package main

import (
	"embed"
	"encoding/json"
	"fmt"
	"io"
	"io/fs"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"sort"

	"github.com/kv/clearnup/backend/internal/apps"
	"github.com/kv/clearnup/backend/internal/cleaner"
	"github.com/kv/clearnup/backend/internal/platform"
	"github.com/kv/clearnup/backend/internal/scanner"
)

//go:embed all:dist
var distFS embed.FS

const Port = ":36969"

func enableCors(w *http.ResponseWriter) {
	(*w).Header().Set("Access-Control-Allow-Origin", "*")
	(*w).Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
	(*w).Header().Set("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
}

func main() {
	http.HandleFunc("/api/disk-usage", handleDiskUsage)
	http.HandleFunc("/api/scan/user", handleScanUser)
	http.HandleFunc("/api/scan/system", handleScanSystem) // Detailed list
	http.HandleFunc("/api/scan/sizes", handleScanSizes)   // Fast summary
	http.HandleFunc("/api/scan/deepest", handleDeepestScan)

	http.HandleFunc("/api/scan/category", handleScanCategory)
	http.HandleFunc("/api/purge", handlePurge)
	http.HandleFunc("/api/empty-trash", handleEmptyTrash)
	http.HandleFunc("/api/clear-cache", handleClearCache)
	http.HandleFunc("/api/clean-docker", handleCleanDocker)
	http.HandleFunc("/api/system-info", handleSystemInfo)
	http.HandleFunc("/api/estimates", handleCleaningEstimates)

	// App Uninstaller
	http.HandleFunc("/api/apps", handleScanApps)
	http.HandleFunc("/api/apps/details", handleAppDetails)
	http.HandleFunc("/api/apps/action", handleAppAction)
	http.HandleFunc("/api/apps/uninstall", handleAppUninstall)

	// Static File Serving (SPA Support)
	// Check if we are running with embedded files or local dist
	// Priority: Embedded (Production) -> Local dist (Dev/Preview)

	// Try to get a sub-fs for "dist" from the embedded FS
	distRoot, err := fs.Sub(distFS, "dist")
	if err == nil {
		fmt.Println("📂 Serving embedded static files")
		// Check if it's actually populated (sanity check)
		if _, err := distRoot.Open("index.html"); err == nil {
			fsrv := http.FileServer(http.FS(distRoot))
			http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
				if filepath.Ext(r.URL.Path) == "" {
					// Read index.html from embedded
					index, _ := distRoot.Open("index.html")
					stat, _ := index.Stat()
					http.ServeContent(w, r, "index.html", stat.ModTime(), index.(io.ReadSeeker))
					return
				}
				fsrv.ServeHTTP(w, r)
			})
		} else {
			// Fallback to local ./dist if embedded is empty (e.g. dev mode without build)
			if _, err := os.Stat("dist"); err == nil {
				fmt.Println("📂 Serving static files from local ./dist")
				fs := http.FileServer(http.Dir("dist"))
				http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
					if filepath.Ext(r.URL.Path) == "" {
						http.ServeFile(w, r, "dist/index.html")
						return
					}
					fs.ServeHTTP(w, r)
				})
			}
		}
	}

	fmt.Printf("🚀 Antigravity Backend running on http://localhost%s\n", Port)

	// Open Browser if not in development mode
	if os.Getenv("APP_ENV") != "development" {
		go platform.OpenBrowser("http://localhost" + Port)
	}

	if err := http.ListenAndServe(Port, nil); err != nil {
		fmt.Printf("Server failed: %s\n", err)
	}
}

type ScanRequest struct {
	Category string `json:"category"` // "apps", "photos", "icloud", "docs", "system"
}

func handleScanCategory(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	var req ScanRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid body", http.StatusBadRequest)
		return
	}

	targets := scanner.GetScanTargets(req.Category)
	if len(targets) == 0 {
		json.NewEncoder(w).Encode([]scanner.ScanResult{})
		return
	}

	var allResults []scanner.ScanResult
	for _, t := range targets {
		if t == "" {
			continue
		}
		res, _ := scanner.FindLargeFiles(t, 10*1024*1024) // 10MB
		allResults = append(allResults, res...)
	}

	// Sort
	sort.Slice(allResults, func(i, j int) bool {
		return allResults[i].Size > allResults[j].Size
	})
	if len(allResults) > 50 {
		allResults = allResults[:50]
	}

	json.NewEncoder(w).Encode(allResults)
}

func handleOpenSettings(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	if err := platform.OpenSettings(); err != nil {
		fmt.Printf("Failed to open settings: %v\n", err)
	}
	w.WriteHeader(http.StatusOK)
}

func handleDiskUsage(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	usage, err := scanner.GetDiskUsage()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(usage)
}

func handleScanUser(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	files, err := scanner.ScanUserDocuments()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(files)
}

func handleScanSizes(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	sizes, err := scanner.GetCategorySizes()
	if err != nil {
		// Log but return empty
		fmt.Println("Size scan error:", err)
		json.NewEncoder(w).Encode(map[string]int64{})
		return
	}
	json.NewEncoder(w).Encode(sizes)
}

func handleScanSystem(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	files, err := scanner.ScanSystemData()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(files)
}

func handleDeepestScan(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	// Default to Documents for now, or parse body for path
	home, _ := os.UserHomeDir()
	target := filepath.Join(home, "Documents")

	folders, err := scanner.FindHeavyFolders(target)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(folders)
}

type PurgeRequest struct {
	Path string `json:"path"`
}

func handlePurge(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	var req PurgeRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	if err := cleaner.PurgePath(req.Path); err != nil {
		http.Error(w, fmt.Sprintf("Failed to purge: %s", err), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]bool{"success": true})
}

func handleEmptyTrash(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	if err := platform.EmptyTrash(); err != nil {
		http.Error(w, fmt.Sprintf("Cannot empty trash: %v", err), http.StatusInternalServerError)
		return
	}

	json.NewEncoder(w).Encode(map[string]bool{"success": true})
}

func handleClearCache(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	cachePath, err := platform.GetCachePath()
	if err != nil {
		http.Error(w, "Cannot get cache path", http.StatusInternalServerError)
		return
	}

	// Get size before clearing
	sizeBefore := scanner.GetDirectorySize(cachePath)

	// Clear cache directories (keep the Caches folder itself if possible, or jus remove content)
	entries, err := os.ReadDir(cachePath)
	if err != nil {
		http.Error(w, "Cannot read cache directory", http.StatusInternalServerError)
		return
	}

	for _, entry := range entries {
		itemPath := filepath.Join(cachePath, entry.Name())
		os.RemoveAll(itemPath)
	}

	json.NewEncoder(w).Encode(map[string]int64{"cleared": sizeBefore})
}

func handleCleanDocker(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	dockerPath, err := platform.GetDockerPath()
	if err != nil {
		json.NewEncoder(w).Encode(map[string]interface{}{
			"cleared": 0,
			"message": "Docker not found",
		})
		return
	}

	// Run docker system prune -af --volumes to clean images, containers, and volumes
	cmd := exec.Command(dockerPath, "system", "prune", "-af", "--volumes")
	output, err := cmd.CombinedOutput()

	if err != nil {
		json.NewEncoder(w).Encode(map[string]interface{}{
			"cleared": 0,
			"message": fmt.Sprintf("Docker cleanup failed: %s", err),
		})
		return
	}

	json.NewEncoder(w).Encode(map[string]interface{}{
		"cleared": 1,
		"message": string(output),
	})
}

func handleSystemInfo(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	info, err := platform.GetSystemInfo()
	if err != nil {
		http.Error(w, "Failed to get system info", http.StatusInternalServerError)
		return
	}

	json.NewEncoder(w).Encode(info)
}

func handleCleaningEstimates(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	estimates, err := scanner.GetCleaningEstimates()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(estimates)
}

// App Uninstaller Handlers

func handleScanApps(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	appsList, err := apps.ScanApps()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(appsList)
}

func handleAppDetails(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	type AppDetailsRequest struct {
		Path     string `json:"path"`
		BundleID string `json:"bundleID"`
	}
	var req AppDetailsRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	details, err := apps.GetAppDetails(req.Path, req.BundleID)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(details)
}

func handleAppAction(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	var req struct {
		Files []string `json:"files"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	if err := apps.DeleteFiles(req.Files); err != nil {
		http.Error(w, fmt.Sprintf("Failed to delete files: %s", err), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]bool{"success": true})
}

func handleAppUninstall(w http.ResponseWriter, r *http.Request) {
	enableCors(&w)
	if r.Method == "OPTIONS" {
		return
	}

	var req struct {
		Cmd string `json:"cmd"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	if err := apps.RunUninstaller(req.Cmd); err != nil {
		http.Error(w, fmt.Sprintf("Failed to launch uninstaller: %s", err), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]bool{"success": true})
}