use agent_client_protocol::schema as acp;
use anyhow::{Context as _, Result, bail};
use file_icons::FileIcons;
use serde::{Deserialize, Serialize};
use std::{
    borrow::Cow,
    fmt,
    ops::RangeInclusive,
    path::{Path, PathBuf},
};
use ui::{App, IconName, SharedString};
use url::Url;
use urlencoding::decode;
use util::{
    ResultExt,
    paths::{PathStyle, PathWithPosition, is_absolute},
};

#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Hash)]
pub enum MentionUri {
    File {
        abs_path: PathBuf,
    },
    PastedImage {
        name: String,
    },
    Directory {
        abs_path: PathBuf,
    },
    Symbol {
        abs_path: PathBuf,
        name: String,
        line_range: RangeInclusive<u32>,
    },
    Thread {
        id: acp::SessionId,
        name: String,
    },
    Diagnostics {
        #[serde(default = "default_include_errors")]
        include_errors: bool,
        #[serde(default)]
        include_warnings: bool,
    },
    Selection {
        #[serde(default, skip_serializing_if = "Option::is_none")]
        abs_path: Option<PathBuf>,
        line_range: RangeInclusive<u32>,
        #[serde(default, skip_serializing_if = "Option::is_none")]
        column: Option<u32>,
    },
    Fetch {
        url: Url,
    },
    TerminalSelection {
        line_count: u32,
    },
    GitDiff {
        base_ref: String,
    },
    MergeConflict {
        file_path: String,
    },
    Skill {
        name: String,
        source: String,
        skill_file_path: PathBuf,
    },
}

impl MentionUri {
    pub fn parse(input: &str, path_style: PathStyle) -> Result<Self> {
        let input = input
            .strip_prefix('`')
            .and_then(|input| input.strip_suffix('`'))
            .unwrap_or(input);

        fn parse_line_range(fragment: &str) -> Result<RangeInclusive<u32>> {
            let range = fragment.strip_prefix("L").unwrap_or(fragment);

            let (start, end) = if let Some((start, end)) = range.split_once(":") {
                (start, end)
            } else if let Some((start, end)) = range.split_once("-") {
                // Also handle L10-20 or L10-L20 format
                (start, end.strip_prefix("L").unwrap_or(end))
            } else {
                // Single line number like L1872 - treat as a range of one line
                (range, range)
            };

            let start_line = start
                .parse::<u32>()
                .context("Parsing line range start")?
                .checked_sub(1)
                .context("Line numbers should be 1-based")?;
            let end_line = end
                .parse::<u32>()
                .context("Parsing line range end")?
                .checked_sub(1)
                .context("Line numbers should be 1-based")?;

            Ok(start_line..=end_line)
        }

        let parse_column =
            |input: Option<String>| -> Option<u32> { input?.parse::<u32>().ok()?.checked_sub(1) };
        let validate_query_params = |url: &Url, allowed: &[&str]| -> Result<()> {
            for (key, _) in url.query_pairs() {
                if !allowed.contains(&key.as_ref()) {
                    bail!("invalid query parameter")
                }
            }
            Ok(())
        };

        let parse_absolute_path = |input: &str| -> Result<Self> {
            let (path_input, fragment) = input
                .split_once('#')
                .map_or((input, None), |(path, fragment)| (path, Some(fragment)));

            if let Some(fragment) = fragment.and_then(|fragment| parse_line_range(fragment).ok()) {
                return Ok(MentionUri::Selection {
                    abs_path: Some(path_input.into()),
                    line_range: fragment,
                    column: None,
                });
            }

            let path_with_position = PathWithPosition::parse_str(path_input);
            let abs_path = path_with_position.path;
            if let Some(row) = path_with_position.row {
                let line = row
                    .checked_sub(1)
                    .context("Line numbers should be 1-based")?;
                Ok(MentionUri::Selection {
                    abs_path: Some(abs_path),
                    line_range: line..=line,
                    column: path_with_position
                        .column
                        .map(|column| column.saturating_sub(1)),
                })
            } else {
                Ok(MentionUri::File { abs_path })
            }
        };

        if is_absolute(input, path_style) && !input.contains("://") {
            return parse_absolute_path(input)
                .with_context(|| format!("Invalid absolute path mention URI: {input}"));
        }

        let url = url::Url::parse(input)?;
        let path = url.path();
        match url.scheme() {
            "file" => {
                let trimmed = if path_style.is_windows() {
                    path.trim_start_matches("/")
                } else {
                    path
                };
                let decoded = decode(trimmed).unwrap_or(Cow::Borrowed(trimmed));
                let normalized: Cow<str> = if path_style.is_windows() {
                    Cow::Owned(decoded.replace('/', "\\"))
                } else {
                    decoded
                };
                let path = normalized.as_ref();

                if let Some(fragment) = url.fragment() {
                    validate_query_params(&url, &["symbol", "column"])?;
                    let line_range = parse_line_range(fragment).log_err().unwrap_or(1..=1);
                    let column = parse_column(query_param(&url, "column"));
                    if let Some(name) = query_param(&url, "symbol") {
                        Ok(Self::Symbol {
                            name,
                            abs_path: path.into(),
                            line_range,
                        })
                    } else {
                        Ok(Self::Selection {
                            abs_path: Some(path.into()),
                            line_range,
                            column,
                        })
                    }
                } else if input.ends_with("/") {
                    Ok(Self::Directory {
                        abs_path: path.into(),
                    })
                } else {
                    Ok(Self::File {
                        abs_path: path.into(),
                    })
                }
            }
            "zed" => {
                if let Some(thread_id) = path.strip_prefix("/agent/thread/") {
                    let name = single_query_param(&url, "name")?.context("Missing thread name")?;
                    Ok(Self::Thread {
                        id: acp::SessionId::new(thread_id),
                        name,
                    })
                } else if path == "/agent/diagnostics" {
                    let mut include_errors = default_include_errors();
                    let mut include_warnings = false;
                    for (key, value) in url.query_pairs() {
                        match key.as_ref() {
                            "include_warnings" => include_warnings = value == "true",
                            "include_errors" => include_errors = value == "true",
                            _ => bail!("invalid query parameter"),
                        }
                    }
                    Ok(Self::Diagnostics {
                        include_errors,
                        include_warnings,
                    })
                } else if path.starts_with("/agent/pasted-image") {
                    let name =
                        single_query_param(&url, "name")?.unwrap_or_else(|| "Image".to_string());
                    Ok(Self::PastedImage { name })
                } else if path.starts_with("/agent/untitled-buffer") {
                    let fragment = url
                        .fragment()
                        .context("Missing fragment for untitled buffer selection")?;
                    let line_range = parse_line_range(fragment)?;
                    validate_query_params(&url, &["column"])?;
                    Ok(Self::Selection {
                        abs_path: None,
                        line_range,
                        column: parse_column(query_param(&url, "column")),
                    })
                } else if let Some(name) = path.strip_prefix("/agent/symbol/") {
                    let fragment = url
                        .fragment()
                        .context("Missing fragment for untitled buffer selection")?;
                    let line_range = parse_line_range(fragment)?;
                    let path =
                        single_query_param(&url, "path")?.context("Missing path for symbol")?;
                    Ok(Self::Symbol {
                        name: name.to_string(),
                        abs_path: path.into(),
                        line_range,
                    })
                } else if path.starts_with("/agent/file") {
                    let path =
                        single_query_param(&url, "path")?.context("Missing path for file")?;
                    Ok(Self::File {
                        abs_path: path.into(),
                    })
                } else if path.starts_with("/agent/directory") {
                    let path =
                        single_query_param(&url, "path")?.context("Missing path for directory")?;
                    Ok(Self::Directory {
                        abs_path: path.into(),
                    })
                } else if path.starts_with("/agent/selection") {
                    validate_query_params(&url, &["path", "column"])?;
                    let fragment = url.fragment().context("Missing fragment for selection")?;
                    let line_range = parse_line_range(fragment)?;
                    let column = parse_column(query_param(&url, "column"));
                    let path = query_param(&url, "path").context("Missing path for selection")?;
                    Ok(Self::Selection {
                        abs_path: Some(path.into()),
                        line_range,
                        column,
                    })
                } else if path.starts_with("/agent/terminal-selection") {
                    let line_count = single_query_param(&url, "lines")?
                        .unwrap_or_else(|| "0".to_string())
                        .parse::<u32>()
                        .unwrap_or(0);
                    Ok(Self::TerminalSelection { line_count })
                } else if path.starts_with("/agent/git-diff") {
                    let base_ref =
                        single_query_param(&url, "base")?.unwrap_or_else(|| "main".to_string());
                    Ok(Self::GitDiff { base_ref })
                } else if path.starts_with("/agent/merge-conflict") {
                    let file_path = single_query_param(&url, "path")?.unwrap_or_default();
                    Ok(Self::MergeConflict { file_path })
                } else if path.starts_with("/agent/skill") {
                    let mut name = None;
                    let mut source = None;
                    let mut skill_file_path = None;

                    for (key, value) in url.query_pairs() {
                        match key.as_ref() {
                            "name" => {
                                if name.replace(value.to_string()).is_some() {
                                    bail!("duplicate skill name query parameter");
                                }
                            }
                            "source" => {
                                if source.replace(value.to_string()).is_some() {
                                    bail!("duplicate skill source query parameter");
                                }
                            }
                            "path" => {
                                if skill_file_path
                                    .replace(PathBuf::from(value.to_string()))
                                    .is_some()
                                {
                                    bail!("duplicate skill file path query parameter");
                                }
                            }
                            _ => bail!("invalid query parameter"),
                        }
                    }

                    Ok(Self::Skill {
                        name: name.context("missing skill name")?,
                        source: source.context("missing skill source")?,
                        skill_file_path: skill_file_path.context("missing skill file path")?,
                    })
                } else {
                    bail!("invalid zed url: {:?}", input);
                }
            }
            "http" | "https" => Ok(MentionUri::Fetch { url }),
            other => bail!("unrecognized scheme {:?}", other),
        }
    }

    pub fn name(&self) -> String {
        match self {
            MentionUri::File { abs_path, .. } | MentionUri::Directory { abs_path, .. } => abs_path
                .file_name()
                .unwrap_or_default()
                .to_string_lossy()
                .into_owned(),
            MentionUri::PastedImage { name } => name.clone(),
            MentionUri::Symbol { name, .. } => name.clone(),
            MentionUri::Thread { name, .. } => name.clone(),
            MentionUri::Diagnostics { .. } => "Diagnostics".to_string(),
            MentionUri::TerminalSelection { line_count } => {
                if *line_count == 1 {
                    "Terminal (1 line)".to_string()
                } else {
                    format!("Terminal ({} lines)", line_count)
                }
            }
            MentionUri::GitDiff { base_ref } => format!("Branch Diff ({})", base_ref),
            MentionUri::MergeConflict { file_path } => {
                let name = Path::new(file_path)
                    .file_name()
                    .unwrap_or_default()
                    .to_string_lossy();
                format!("Merge Conflict ({name})")
            }
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => selection_name(path.as_deref(), line_range),
            MentionUri::Fetch { url } => url.to_string(),
            MentionUri::Skill { name, .. } => name.clone(),
        }
    }

    /// Returns a label for this mention at the given disambiguation `detail`
    /// level. `detail == 0` is the base name returned by [`Self::name`]; higher
    /// levels include progressively more context (e.g. additional parent path
    /// components for files, or the source for skills) until a fixed point is
    /// reached. Intended to be driven by [`util::disambiguate::compute_disambiguation_details`].
    pub fn disambiguated_name(&self, detail: usize) -> String {
        if detail == 0 {
            return self.name();
        }

        match self {
            MentionUri::Skill { name, source, .. } => {
                if source.is_empty() {
                    // Must match `SkillSource::display_label()` in agent_skills.
                    format!("{} (global)", name)
                } else {
                    format!("{} ({})", name, source)
                }
            }
            MentionUri::File { abs_path, .. } | MentionUri::Directory { abs_path, .. } => {
                project::path_suffix(abs_path, detail)
            }
            _ => self.name(),
        }
    }

    pub fn tooltip_text(&self) -> Option<SharedString> {
        match self {
            MentionUri::File { abs_path } | MentionUri::Directory { abs_path } => {
                Some(abs_path.to_string_lossy().into_owned().into())
            }
            MentionUri::Symbol {
                abs_path,
                line_range,
                ..
            } => Some(
                format!(
                    "{}:{}-{}",
                    abs_path.display(),
                    line_range.start(),
                    line_range.end()
                )
                .into(),
            ),
            MentionUri::Selection {
                abs_path: Some(path),
                line_range,
                ..
            } => Some(
                format!(
                    "{}:{}-{}",
                    path.display(),
                    line_range.start(),
                    line_range.end()
                )
                .into(),
            ),
            MentionUri::Skill {
                skill_file_path, ..
            } => Some(skill_file_path.to_string_lossy().into_owned().into()),
            _ => None,
        }
    }

    pub fn icon_path(&self, cx: &mut App) -> SharedString {
        match self {
            MentionUri::File { abs_path } => {
                FileIcons::get_icon(abs_path, cx).unwrap_or_else(|| IconName::File.path().into())
            }
            MentionUri::PastedImage { .. } => IconName::Image.path().into(),
            MentionUri::Directory { abs_path } => FileIcons::get_folder_icon(false, abs_path, cx)
                .unwrap_or_else(|| IconName::Folder.path().into()),
            MentionUri::Symbol { .. } => IconName::Code.path().into(),
            MentionUri::Thread { .. } => IconName::Thread.path().into(),
            MentionUri::Diagnostics { .. } => IconName::Warning.path().into(),
            MentionUri::TerminalSelection { .. } => IconName::Terminal.path().into(),
            MentionUri::Selection { .. } => IconName::Reader.path().into(),
            MentionUri::Fetch { .. } => IconName::ToolWeb.path().into(),
            MentionUri::GitDiff { .. } => IconName::GitBranch.path().into(),
            MentionUri::MergeConflict { .. } => IconName::GitMergeConflict.path().into(),
            MentionUri::Skill { .. } => IconName::Sparkle.path().into(),
        }
    }

    pub fn as_link<'a>(&'a self) -> MentionLink<'a> {
        MentionLink(self)
    }

    pub fn to_uri(&self) -> Url {
        match self {
            MentionUri::File { abs_path } => {
                let mut url = Url::parse("file:///").unwrap();
                url.set_path(&abs_path.to_string_lossy());
                url
            }
            MentionUri::PastedImage { name } => {
                let mut url = Url::parse("zed:///agent/pasted-image").unwrap();
                url.query_pairs_mut().append_pair("name", name);
                url
            }
            MentionUri::Directory { abs_path } => {
                let mut url = Url::parse("file:///").unwrap();
                let mut path = abs_path.to_string_lossy().into_owned();
                if !path.ends_with('/') && !path.ends_with('\\') {
                    path.push('/');
                }
                url.set_path(&path);
                url
            }
            MentionUri::Symbol {
                abs_path,
                name,
                line_range,
                ..
            } => {
                let mut url = Url::parse("file:///").unwrap();
                url.set_path(&abs_path.to_string_lossy());
                url.query_pairs_mut().append_pair("symbol", name);
                url.set_fragment(Some(&format!(
                    "L{}:{}",
                    line_range.start() + 1,
                    line_range.end() + 1
                )));
                url
            }
            MentionUri::Selection {
                abs_path,
                line_range,
                column,
            } => {
                let mut url = if let Some(path) = abs_path {
                    let mut url = Url::parse("file:///").unwrap();
                    url.set_path(&path.to_string_lossy());
                    url
                } else {
                    let mut url = Url::parse("zed:///").unwrap();
                    url.set_path("/agent/untitled-buffer");
                    url
                };
                if let Some(column) = column {
                    url.query_pairs_mut()
                        .append_pair("column", &(column + 1).to_string());
                }
                url.set_fragment(Some(&format!(
                    "L{}:{}",
                    line_range.start() + 1,
                    line_range.end() + 1
                )));
                url
            }
            MentionUri::Thread { name, id } => {
                let mut url = Url::parse("zed:///").unwrap();
                url.set_path(&format!("/agent/thread/{id}"));
                url.query_pairs_mut().append_pair("name", name);
                url
            }
            MentionUri::Diagnostics {
                include_errors,
                include_warnings,
            } => {
                let mut url = Url::parse("zed:///").unwrap();
                url.set_path("/agent/diagnostics");
                if *include_warnings {
                    url.query_pairs_mut()
                        .append_pair("include_warnings", "true");
                }
                if !include_errors {
                    url.query_pairs_mut().append_pair("include_errors", "false");
                }
                url
            }
            MentionUri::Fetch { url } => url.clone(),
            MentionUri::TerminalSelection { line_count } => {
                let mut url = Url::parse("zed:///agent/terminal-selection").unwrap();
                url.query_pairs_mut()
                    .append_pair("lines", &line_count.to_string());
                url
            }
            MentionUri::GitDiff { base_ref } => {
                let mut url = Url::parse("zed:///agent/git-diff").unwrap();
                url.query_pairs_mut().append_pair("base", base_ref);
                url
            }
            MentionUri::MergeConflict { file_path } => {
                let mut url = Url::parse("zed:///agent/merge-conflict").unwrap();
                url.query_pairs_mut().append_pair("path", file_path);
                url
            }
            MentionUri::Skill {
                name,
                source,
                skill_file_path,
            } => {
                let mut url = Url::parse("zed:///").unwrap();
                url.set_path("/agent/skill");
                url.query_pairs_mut()
                    .append_pair("name", name)
                    .append_pair("source", source)
                    .append_pair("path", &skill_file_path.to_string_lossy());
                url
            }
        }
    }
}

pub struct MentionLink<'a>(&'a MentionUri);

impl fmt::Display for MentionLink<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "[@{}]({})", self.0.name(), self.0.to_uri())
    }
}

fn default_include_errors() -> bool {
    true
}

fn query_param(url: &Url, name: &'static str) -> Option<String> {
    url.query_pairs()
        .find_map(|(key, value)| (key == name).then(|| value.to_string()))
}

fn single_query_param(url: &Url, name: &'static str) -> Result<Option<String>> {
    let pairs = url.query_pairs().collect::<Vec<_>>();
    match pairs.as_slice() {
        [] => Ok(None),
        [(k, v)] => {
            if k != name {
                bail!("invalid query parameter")
            }

            Ok(Some(v.to_string()))
        }
        _ => bail!("too many query pairs"),
    }
}

pub fn selection_name(path: Option<&Path>, line_range: &RangeInclusive<u32>) -> String {
    format!(
        "{} ({}:{})",
        path.and_then(|path| path.file_name())
            .unwrap_or("Untitled".as_ref())
            .display(),
        *line_range.start() + 1,
        *line_range.end() + 1
    )
}

#[cfg(test)]
mod tests {
    use util::{path, uri};

    use super::*;

    #[test]
    fn test_parse_file_uri() {
        let file_uri = uri!("file:///path/to/file.rs");
        let parsed = MentionUri::parse(file_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::File { abs_path } => {
                assert_eq!(abs_path, Path::new(path!("/path/to/file.rs")));
            }
            _ => panic!("Expected File variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), file_uri);
    }

    #[test]
    fn test_parse_directory_uri() {
        let file_uri = uri!("file:///path/to/dir/");
        let parsed = MentionUri::parse(file_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Directory { abs_path } => {
                assert_eq!(abs_path, Path::new(path!("/path/to/dir/")));
            }
            _ => panic!("Expected Directory variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), file_uri);
    }

    #[test]
    fn test_parse_file_uris_use_native_separators_on_windows() {
        let parsed = MentionUri::parse("file:///C:/path/to/file.rs", PathStyle::Windows).unwrap();
        match parsed {
            MentionUri::File { abs_path } => {
                assert_eq!(abs_path, PathBuf::from("C:\\path\\to\\file.rs"));
            }
            other => panic!("Expected File variant, got {other:?}"),
        }

        let parsed = MentionUri::parse("file:///C:/path/to/dir/", PathStyle::Windows).unwrap();
        match parsed {
            MentionUri::Directory { abs_path } => {
                assert_eq!(abs_path, PathBuf::from("C:\\path\\to\\dir\\"));
            }
            other => panic!("Expected Directory variant, got {other:?}"),
        }

        let parsed = MentionUri::parse(
            "file:///C:/path/to/file.rs?symbol=MySymbol#L10:20",
            PathStyle::Windows,
        )
        .unwrap();
        match parsed {
            MentionUri::Symbol { abs_path, .. } => {
                assert_eq!(abs_path, PathBuf::from("C:\\path\\to\\file.rs"));
            }
            other => panic!("Expected Symbol variant, got {other:?}"),
        }

        let parsed =
            MentionUri::parse("file:///C:/path/to/file.rs#L5:15", PathStyle::Windows).unwrap();
        match parsed {
            MentionUri::Selection {
                abs_path: Some(abs_path),
                ..
            } => {
                assert_eq!(abs_path, PathBuf::from("C:\\path\\to\\file.rs"));
            }
            other => panic!("Expected Selection variant, got {other:?}"),
        }
    }

    #[test]
    fn test_to_directory_uri_without_slash() {
        let uri = MentionUri::Directory {
            abs_path: PathBuf::from(path!("/path/to/dir/")),
        };
        let expected = uri!("file:///path/to/dir/");
        assert_eq!(uri.to_uri().to_string(), expected);
    }

    #[test]
    fn test_directory_uri_round_trip_without_trailing_slash() {
        let uri = MentionUri::Directory {
            abs_path: PathBuf::from(path!("/path/to/dir")),
        };
        let serialized = uri.to_uri().to_string();
        assert!(serialized.ends_with('/'), "directory URI must end with /");
        let parsed = MentionUri::parse(&serialized, PathStyle::local()).unwrap();
        assert!(
            matches!(parsed, MentionUri::Directory { .. }),
            "expected Directory variant, got {:?}",
            parsed
        );
    }

    #[test]
    fn test_parse_symbol_uri() {
        let symbol_uri = uri!("file:///path/to/file.rs?symbol=MySymbol#L10:20");
        let parsed = MentionUri::parse(symbol_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Symbol {
                abs_path: path,
                name,
                line_range,
                ..
            } => {
                assert_eq!(path, Path::new(path!("/path/to/file.rs")));
                assert_eq!(name, "MySymbol");
                assert_eq!(line_range.start(), &9);
                assert_eq!(line_range.end(), &19);
            }
            _ => panic!("Expected Symbol variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), symbol_uri);
    }

    #[test]
    fn test_parse_selection_uri() {
        let selection_uri = uri!("file:///path/to/file.rs#L5:15");
        let parsed = MentionUri::parse(selection_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new(path!("/path/to/file.rs")));
                assert_eq!(line_range.start(), &4);
                assert_eq!(line_range.end(), &14);
            }
            _ => panic!("Expected Selection variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), selection_uri);
    }

    #[test]
    fn test_parse_file_uri_with_non_ascii() {
        let file_uri = uri!("file:///path/to/%E6%97%A5%E6%9C%AC%E8%AA%9E.txt");
        let parsed = MentionUri::parse(file_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::File { abs_path } => {
                assert_eq!(abs_path, Path::new(path!("/path/to/日本語.txt")));
            }
            _ => panic!("Expected File variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), file_uri);
    }

    #[test]
    fn test_parse_untitled_selection_uri() {
        let selection_uri = uri!("zed:///agent/untitled-buffer#L1:10");
        let parsed = MentionUri::parse(selection_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: None,
                line_range,
                ..
            } => {
                assert_eq!(line_range.start(), &0);
                assert_eq!(line_range.end(), &9);
            }
            _ => panic!("Expected Selection variant without path"),
        }
        assert_eq!(parsed.to_uri().to_string(), selection_uri);
    }

    #[test]
    fn test_parse_thread_uri() {
        let thread_uri = "zed:///agent/thread/session123?name=Thread+name";
        let parsed = MentionUri::parse(thread_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Thread {
                id: thread_id,
                name,
            } => {
                assert_eq!(thread_id.to_string(), "session123");
                assert_eq!(name, "Thread name");
            }
            _ => panic!("Expected Thread variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), thread_uri);
    }

    #[test]
    fn test_parse_skill_uri_round_trip() {
        let skill_uri = MentionUri::Skill {
            name: "rust-best-practices".to_string(),
            source: "my-personal-project".to_string(),
            skill_file_path: PathBuf::from(path!("/path/to/skills/rust-best-practices/SKILL.md")),
        };

        let serialized = skill_uri.to_uri().to_string();
        let parsed = MentionUri::parse(&serialized, PathStyle::local()).unwrap();

        assert_eq!(parsed, skill_uri);
    }

    #[test]
    fn test_parse_fetch_http_uri() {
        let http_uri = "http://example.com/path?query=value#fragment";
        let parsed = MentionUri::parse(http_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Fetch { url } => {
                assert_eq!(url.to_string(), http_uri);
            }
            _ => panic!("Expected Fetch variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), http_uri);
    }

    #[test]
    fn test_parse_fetch_https_uri() {
        let https_uri = "https://example.com/api/endpoint";
        let parsed = MentionUri::parse(https_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Fetch { url } => {
                assert_eq!(url.to_string(), https_uri);
            }
            _ => panic!("Expected Fetch variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), https_uri);
    }

    #[test]
    fn test_parse_diagnostics_uri() {
        let uri = "zed:///agent/diagnostics?include_warnings=true";
        let parsed = MentionUri::parse(uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Diagnostics {
                include_errors,
                include_warnings,
            } => {
                assert!(include_errors);
                assert!(include_warnings);
            }
            _ => panic!("Expected Diagnostics variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), uri);
    }

    #[test]
    fn test_parse_diagnostics_uri_warnings_only() {
        let uri = "zed:///agent/diagnostics?include_warnings=true&include_errors=false";
        let parsed = MentionUri::parse(uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Diagnostics {
                include_errors,
                include_warnings,
            } => {
                assert!(!include_errors);
                assert!(include_warnings);
            }
            _ => panic!("Expected Diagnostics variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), uri);
    }

    #[test]
    fn test_invalid_scheme() {
        assert!(MentionUri::parse("ftp://example.com", PathStyle::local()).is_err());
        assert!(MentionUri::parse("ssh://example.com", PathStyle::local()).is_err());
        assert!(MentionUri::parse("unknown://example.com", PathStyle::local()).is_err());
    }

    #[test]
    fn test_invalid_zed_path() {
        assert!(MentionUri::parse("zed:///invalid/path", PathStyle::local()).is_err());
        assert!(MentionUri::parse("zed:///agent/unknown/test", PathStyle::local()).is_err());
    }

    #[test]
    fn test_parse_absolute_file_path() {
        let file_path = path!("/path/to/file.rs");
        let parsed = MentionUri::parse(file_path, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::File { abs_path } => {
                assert_eq!(abs_path, Path::new(file_path));
            }
            _ => panic!("Expected File variant"),
        }
    }

    #[test]
    fn test_parse_absolute_file_path_with_row() {
        let file_path = "/path/to/file.rs:42";
        let parsed = MentionUri::parse(file_path, PathStyle::Posix).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new("/path/to/file.rs"));
                assert_eq!(line_range.start(), &41);
                assert_eq!(line_range.end(), &41);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_parse_absolute_file_path_with_row_and_column() {
        let file_path = "/path/to/file.rs:42:5";
        let parsed = MentionUri::parse(file_path, PathStyle::Posix).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                column,
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new("/path/to/file.rs"));
                assert_eq!(line_range.start(), &41);
                assert_eq!(line_range.end(), &41);
                assert_eq!(column, &Some(4));

                let parsed_again = MentionUri::parse(parsed.to_uri().as_ref(), PathStyle::Posix)
                    .expect("selection URI with column should parse");
                assert_eq!(parsed_again, parsed.clone());
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_parse_absolute_file_path_with_fragment_line() {
        let file_path = "/path/to/file.rs#L42";
        let parsed = MentionUri::parse(file_path, PathStyle::Posix).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new("/path/to/file.rs"));
                assert_eq!(line_range.start(), &41);
                assert_eq!(line_range.end(), &41);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_parse_absolute_windows_path() {
        let file_path = "C:\\Users\\zed\\project\\main.rs";
        let parsed = MentionUri::parse(file_path, PathStyle::Windows).unwrap();
        match &parsed {
            MentionUri::File { abs_path } => {
                assert_eq!(abs_path, Path::new("C:\\Users\\zed\\project\\main.rs"));
            }
            _ => panic!("Expected File variant"),
        }
    }

    #[test]
    fn test_parse_absolute_windows_file_path_with_row() {
        let file_path = "C:\\Users\\zed\\project\\main.rs:42";
        let parsed = MentionUri::parse(file_path, PathStyle::Windows).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(
                    path.as_ref().unwrap(),
                    Path::new("C:\\Users\\zed\\project\\main.rs")
                );
                assert_eq!(line_range.start(), &41);
                assert_eq!(line_range.end(), &41);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_parse_absolute_windows_file_path_with_fragment_line() {
        let file_path = "C:\\Users\\zed\\project\\main.rs#L42";
        let parsed = MentionUri::parse(file_path, PathStyle::Windows).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(
                    path.as_ref().unwrap(),
                    Path::new("C:\\Users\\zed\\project\\main.rs")
                );
                assert_eq!(line_range.start(), &41);
                assert_eq!(line_range.end(), &41);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_parse_backticked_absolute_file_path() {
        let file_path = "`/path/to/file.rs`";
        let parsed = MentionUri::parse(file_path, PathStyle::Posix).unwrap();
        match &parsed {
            MentionUri::File { abs_path } => {
                assert_eq!(abs_path, Path::new("/path/to/file.rs"));
            }
            _ => panic!("Expected File variant"),
        }
    }

    #[test]
    fn test_parse_backticked_absolute_file_path_with_fragment_line() {
        let file_path = "`/path/to/file.rs#L42`";
        let parsed = MentionUri::parse(file_path, PathStyle::Posix).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new("/path/to/file.rs"));
                assert_eq!(line_range.start(), &41);
                assert_eq!(line_range.end(), &41);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_parse_backticked_absolute_windows_file_path_with_fragment_line() {
        let file_path = "`C:\\Users\\zed\\project\\main.rs#L42`";
        let parsed = MentionUri::parse(file_path, PathStyle::Windows).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(
                    path.as_ref().unwrap(),
                    Path::new("C:\\Users\\zed\\project\\main.rs")
                );
                assert_eq!(line_range.start(), &41);
                assert_eq!(line_range.end(), &41);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_single_line_number() {
        // https://github.com/zed-industries/zed/issues/46114
        let uri = uri!("file:///path/to/file.rs#L1872");
        let parsed = MentionUri::parse(uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new(path!("/path/to/file.rs")));
                assert_eq!(line_range.start(), &1871);
                assert_eq!(line_range.end(), &1871);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_dash_separated_line_range() {
        let uri = uri!("file:///path/to/file.rs#L10-20");
        let parsed = MentionUri::parse(uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new(path!("/path/to/file.rs")));
                assert_eq!(line_range.start(), &9);
                assert_eq!(line_range.end(), &19);
            }
            _ => panic!("Expected Selection variant"),
        }

        // Also test L10-L20 format
        let uri = uri!("file:///path/to/file.rs#L10-L20");
        let parsed = MentionUri::parse(uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::Selection {
                abs_path: path,
                line_range,
                ..
            } => {
                assert_eq!(path.as_ref().unwrap(), Path::new(path!("/path/to/file.rs")));
                assert_eq!(line_range.start(), &9);
                assert_eq!(line_range.end(), &19);
            }
            _ => panic!("Expected Selection variant"),
        }
    }

    #[test]
    fn test_parse_terminal_selection_uri() {
        let terminal_uri = "zed:///agent/terminal-selection?lines=42";
        let parsed = MentionUri::parse(terminal_uri, PathStyle::local()).unwrap();
        match &parsed {
            MentionUri::TerminalSelection { line_count } => {
                assert_eq!(*line_count, 42);
            }
            _ => panic!("Expected TerminalSelection variant"),
        }
        assert_eq!(parsed.to_uri().to_string(), terminal_uri);
        assert_eq!(parsed.name(), "Terminal (42 lines)");

        // Test single line
        let single_line_uri = "zed:///agent/terminal-selection?lines=1";
        let parsed_single = MentionUri::parse(single_line_uri, PathStyle::local()).unwrap();
        assert_eq!(parsed_single.name(), "Terminal (1 line)");
    }

    #[test]
    fn test_disambiguated_name() {
        // Two files with the same name — should disambiguate with parent dir
        let file_a = MentionUri::File {
            abs_path: PathBuf::from(path!("/project/src/README.md")),
        };
        let file_b = MentionUri::File {
            abs_path: PathBuf::from(path!("/project/docs/README.md")),
        };
        assert_eq!(file_a.name(), "README.md");
        assert_eq!(file_b.name(), "README.md");
        assert_eq!(file_a.disambiguated_name(0), "README.md");
        assert_eq!(file_a.disambiguated_name(1), "src/README.md");
        assert_eq!(file_b.disambiguated_name(1), "docs/README.md");

        // Files that still collide at one parent should grow further.
        let deep_a = MentionUri::File {
            abs_path: PathBuf::from(path!("/a/src/foo.rs")),
        };
        let deep_b = MentionUri::File {
            abs_path: PathBuf::from(path!("/b/src/foo.rs")),
        };
        assert_eq!(deep_a.disambiguated_name(1), "src/foo.rs");
        assert_eq!(deep_b.disambiguated_name(1), "src/foo.rs");
        assert_eq!(deep_a.disambiguated_name(2), "a/src/foo.rs");
        assert_eq!(deep_b.disambiguated_name(2), "b/src/foo.rs");

        // Two skills with the same name — should disambiguate with source
        let global_skill = MentionUri::Skill {
            name: "create-skill".into(),
            source: "".into(),
            skill_file_path: PathBuf::from("/global/create-skill/SKILL.md"),
        };
        let project_skill = MentionUri::Skill {
            name: "create-skill".into(),
            source: "my-project".into(),
            skill_file_path: PathBuf::from("/project/create-skill/SKILL.md"),
        };
        assert_eq!(global_skill.name(), "create-skill");
        assert_eq!(global_skill.disambiguated_name(0), "create-skill");
        assert_eq!(global_skill.disambiguated_name(1), "create-skill (global)");
        assert_eq!(
            project_skill.disambiguated_name(1),
            "create-skill (my-project)"
        );

        // A type without special disambiguation (Thread) — detail has no effect
        // (the value is a fixed point so the disambiguation loop terminates).
        let thread = MentionUri::Thread {
            id: acp::SessionId::new("123"),
            name: "My Thread".into(),
        };
        assert_eq!(thread.disambiguated_name(0), "My Thread");
        assert_eq!(thread.disambiguated_name(1), "My Thread");
        assert_eq!(thread.disambiguated_name(5), "My Thread");

        // Edge case: file at filesystem root has no parent to show
        let root_file = MentionUri::File {
            abs_path: PathBuf::from(path!("/README.md")),
        };
        assert_eq!(root_file.disambiguated_name(1), "README.md");
        assert_eq!(root_file.disambiguated_name(5), "README.md");
    }
}