package main

import (
	"embed"
	"encoding/json"
	"fmt"
	"io/fs"
	"log"
	"net"
	"net/http"
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"sort"
	"strconv"
	"strings"
	"sync"
	"time"
)

//go:embed web/ui/*
var webUI embed.FS

func cmdServe(args []string) {
	port := 0
	host := "127.0.0.1"
	openBrowser := true

	for i := 0; i < len(args); i++ {
		switch args[i] {
		case "-p", "--port":
			if i+1 < len(args) {
				port, _ = strconv.Atoi(args[i+1])
				i++
			}
		case "--host":
			if i+1 < len(args) {
				host = args[i+1]
				i++
			}
		case "--no-browser":
			openBrowser = false
		}
	}

	mux := http.NewServeMux()

	uiFS, err := fs.Sub(webUI, "web/ui")
	if err != nil {
		fatal("embed web/ui: %v", err)
	}
	mux.Handle("/", http.FileServer(http.FS(uiFS)))

	mux.HandleFunc("/api/search", handleSearch)
	mux.HandleFunc("/api/list", handleList)
	mux.HandleFunc("/api/list-wavs", handleListWavs)
	mux.HandleFunc("/api/download", handleAPIDownload)
	mux.HandleFunc("/api/extract", handleAPIExtract)
	mux.HandleFunc("/api/progress", handleProgress)

	wavsBase := "./output/wavs"
	if abs, err := filepath.Abs(wavsBase); err == nil {
		wavsBase = abs
	}
	if err := os.MkdirAll(wavsBase, 0755); err != nil {
		fatal("create wavs dir: %v", err)
	}
	mux.Handle("/wavs/", http.StripPrefix("/wavs/", http.FileServer(http.Dir(wavsBase))))

	addr := fmt.Sprintf("%s:%d", host, port)
	listener, err := net.Listen("tcp", addr)
	if err != nil {
		fatal("listen: %v", err)
	}

	realPort := listener.Addr().(*net.TCPAddr).Port
	realHost := "0.0.0.0"
	if ip := listener.Addr().(*net.TCPAddr).IP; ip != nil {
		realHost = ip.String()
	}

	fmt.Printf("\n  AKAI Utils Server\n")
	fmt.Printf("  =================\n\n")
	if realHost == "0.0.0.0" || realHost == "::" || realHost == "" || realHost == "<nil>" {
		fmt.Printf("  Local:   http://localhost:%d\n", realPort)
		if realHost == "0.0.0.0" {
			fmt.Printf("  Network: http://<host-ip>:%d\n", realPort)
		}
	} else {
		fmt.Printf("  Local:   http://%s:%d\n", realHost, realPort)
	}
	fmt.Printf("  API:     http://localhost:%d/api/\n", realPort)
	fmt.Printf("  Quit:    Ctrl+C\n\n")

	if openBrowser {
		go func() {
			time.Sleep(500 * time.Millisecond)
			openURL(fmt.Sprintf("http://localhost:%d", realPort))
		}()
	}

	server := &http.Server{Handler: mux}
	log.Fatal(server.Serve(listener))
}

func handleSearch(w http.ResponseWriter, r *http.Request) {
	q := r.URL.Query().Get("q")
	filter := r.URL.Query().Get("filter")
	limitStr := r.URL.Query().Get("limit")

	if q == "" {
		q = "subject:akai AND subject:sampler"
	}
	if filter != "" {
		q = "(" + q + ") AND (" + filter + ")"
	}

	limit := 30
	if limitStr != "" {
		limit, _ = strconv.Atoi(limitStr)
	}

	results := searchArchive(q, limit)
	sort.Slice(results, func(i, j int) bool {
		return results[i].Downloads > results[j].Downloads
	})

	writeJSON(w, results)
}

func handleList(w http.ResponseWriter, r *http.Request) {
	identifier := r.URL.Query().Get("identifier")
	if identifier == "" {
		http.Error(w, "missing identifier", http.StatusBadRequest)
		return
	}
	files := getItemFiles(identifier)
	writeJSON(w, files)
}

var (
	downloadJobs   = make(map[string]*downloadState)
	downloadJobsMu sync.Mutex
)

type downloadState struct {
	ID         string  `json:"id"`
	Identifier string  `json:"identifier"`
	FileName   string  `json:"file_name"`
	TotalSize  int64   `json:"total_size"`
	Downloaded int64   `json:"downloaded"`
	Done       bool    `json:"done"`
	Error      string  `json:"error,omitempty"`
	Speed      float64 `json:"speed"`
	lastCheck  time.Time
	lastBytes  int64
}

func handleAPIDownload(w http.ResponseWriter, r *http.Request) {
	identifier := r.URL.Query().Get("identifier")
	outDir := r.URL.Query().Get("dir")
	if identifier == "" {
		http.Error(w, "missing identifier", http.StatusBadRequest)
		return
	}
	if outDir == "" {
		outDir = "."
	}

	if abs, err := filepath.Abs(outDir); err == nil {
		outDir = abs
	}
	if err := os.MkdirAll(outDir, 0755); err != nil {
		writeJSON(w, map[string]any{"error": fmt.Sprintf("create %s: %v", outDir, err)})
		return
	}

	files := getItemFiles(identifier)
	if len(files) == 0 {
		writeJSON(w, map[string]any{"error": "no ISO files found"})
		return
	}

	var jobIDs []string
	for _, f := range files {
		size, _ := strconv.ParseInt(f.Size, 10, 64)
		jobID := identifier + "/" + f.Name
		state := &downloadState{
			ID:         jobID,
			Identifier: identifier,
			FileName:   f.Name,
			TotalSize:  size,
			lastCheck:  time.Now(),
		}
		downloadJobsMu.Lock()
		downloadJobs[jobID] = state
		downloadJobsMu.Unlock()
		jobIDs = append(jobIDs, jobID)

		go func(j downloadJob, s *downloadState) {
			if err := os.MkdirAll(filepath.Dir(j.OutPath), 0755); err != nil {
				s.Error = err.Error()
				return
			}

			client := &http.Client{Timeout: 0}
			req, _ := http.NewRequest("GET", j.URL, nil)
			req.Header.Set("User-Agent", userAgent)

			if fi, err := os.Stat(j.OutPath); err == nil && j.Size > 0 && fi.Size() == j.Size {
				s.Downloaded = j.Size
				s.Done = true
				return
			}

			resp, err := client.Do(req)
			if err != nil {
				s.Error = err.Error()
				return
			}
			defer func() { _ = resp.Body.Close() }()

			outFile, err := os.Create(j.OutPath)
			if err != nil {
				s.Error = err.Error()
				return
			}
			defer func() { _ = outFile.Close() }()

			buf := make([]byte, 32*1024)
			for {
				n, readErr := resp.Body.Read(buf)
				if n > 0 {
					if _, err := outFile.Write(buf[:n]); err != nil {
						s.Error = err.Error()
						return
					}
					s.Downloaded += int64(n)

					now := time.Now()
					elapsed := now.Sub(s.lastCheck).Seconds()
					if elapsed >= 1.0 {
						s.Speed = float64(s.Downloaded-s.lastBytes) / elapsed
						s.lastCheck = now
						s.lastBytes = s.Downloaded
					}
				}
				if readErr != nil {
					break
				}
			}
			s.Done = true
			s.Speed = 0
		}(downloadJob{
			Identifier: identifier,
			Name:       f.Name,
			URL:        fmt.Sprintf("%s/download/%s/%s", iaBaseURL, url.PathEscape(identifier), url.PathEscape(f.Name)),
			OutPath:    filepath.Join(outDir, f.Name),
			Size:       size,
		}, state)
	}

	writeJSON(w, map[string]any{"jobs": jobIDs})
}

func handleListWavs(w http.ResponseWriter, r *http.Request) {
	dir := r.URL.Query().Get("dir")
	if dir == "" {
		dir = "./output/wavs"
	}
	if abs, err := filepath.Abs(dir); err == nil {
		dir = abs
	}

	entries, err := os.ReadDir(dir)
	if err != nil {
		writeJSON(w, map[string]any{"error": err.Error()})
		return
	}

	files := []string{}
	for _, e := range entries {
		if !e.IsDir() && strings.HasSuffix(strings.ToLower(e.Name()), ".wav") {
			files = append(files, e.Name())
		}
	}
	writeJSON(w, files)
}

func handleProgress(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/event-stream")
	w.Header().Set("Cache-Control", "no-cache")
	w.Header().Set("Connection", "keep-alive")

	flusher, ok := w.(http.Flusher)
	if !ok {
		http.Error(w, "streaming unsupported", http.StatusInternalServerError)
		return
	}

	ticker := time.NewTicker(500 * time.Millisecond)
	defer ticker.Stop()

	for range ticker.C {
		downloadJobsMu.Lock()
		data, _ := json.Marshal(downloadJobs)
		downloadJobsMu.Unlock()

		if _, err := fmt.Fprintf(w, "data: %s\n\n", data); err != nil {
			return
		}
		flusher.Flush()

		allDone := true
		downloadJobsMu.Lock()
		for _, s := range downloadJobs {
			if !s.Done && s.Error == "" {
				allDone = false
				break
			}
		}
		downloadJobsMu.Unlock()
		if allDone && len(downloadJobs) > 0 {
			break
		}
	}
}

func handleAPIExtract(w http.ResponseWriter, r *http.Request) {
	isoDir := r.URL.Query().Get("dir")
	outDir := r.URL.Query().Get("out")
	if isoDir == "" {
		isoDir = "."
	}
	if outDir == "" {
		outDir = "./wavs"
	}

	entries, err := os.ReadDir(isoDir)
	if err != nil {
		writeJSON(w, map[string]any{"error": err.Error()})
		return
	}

	var isos []string
	for _, e := range entries {
		if !e.IsDir() && strings.HasSuffix(strings.ToLower(e.Name()), ".iso") {
			isos = append(isos, filepath.Join(isoDir, e.Name()))
		}
	}

	if len(isos) == 0 {
		writeJSON(w, map[string]any{"error": "no ISO files found in " + isoDir})
		return
	}

	var messages []string
	for _, isoPath := range isos {
		result, err := extractISO(isoPath, outDir)
		if err != nil {
			messages = append(messages, fmt.Sprintf("FAIL %s: %v", filepath.Base(isoPath), err))
		} else {
			messages = append(messages, fmt.Sprintf("OK %s: %s", filepath.Base(isoPath), result))
		}
	}

	writeJSON(w, map[string]any{
		"message": fmt.Sprintf("Extracted %d ISOs: %s", len(isos), strings.Join(messages, "; ")),
	})
}

func writeJSON(w http.ResponseWriter, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	if err := json.NewEncoder(w).Encode(v); err != nil {
		// client disconnected, nothing we can do
		return
	}
}

func openURL(rawURL string) {
	_ = exec.Command("xdg-open", rawURL).Start()
	_ = exec.Command("open", rawURL).Start()
	_ = exec.Command("rundll32", "url.dll,FileProtocolHandler", rawURL).Start()
}

func init() {
	log.SetFlags(0)
}