package controller

import (
	"butterfliu/internal/service"
	"encoding/json"
	"log"
	"net/http"
	"strconv"
	"sync"
	"time"

	"github.com/go-chi/chi/v5"
)

type ScanStatus struct {
	Running    bool                `json:"running"`
	LibraryID  int                 `json:"library_id"`
	Report     *service.ScanReport `json:"report,omitempty"`
	Error      string              `json:"error,omitempty"`
	StartedAt  *time.Time          `json:"started_at,omitempty"`
	FinishedAt *time.Time          `json:"finished_at,omitempty"`
}

type LibraryController struct {
	libraryService *service.LibraryService
	coverService   *service.CoverService
	scanMutex      sync.Mutex
	scanStatus     ScanStatus
}

func NewLibraryController(libraryService *service.LibraryService, coverSvc *service.CoverService) *LibraryController {
	return &LibraryController{libraryService: libraryService, coverService: coverSvc}
}

func (c *LibraryController) GetAll(w http.ResponseWriter, r *http.Request) {
	libraries, err := c.libraryService.GetAll()
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, libraries, http.StatusOK)
}

func (c *LibraryController) Create(w http.ResponseWriter, r *http.Request) {
	var req struct {
		Name string `json:"name"`
		Path string `json:"path"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	if req.Name == "" || req.Path == "" {
		jsonError(w, "name and path are required", http.StatusBadRequest)
		return
	}
	_, err := c.libraryService.Create(req.Name, req.Path)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonMsg(w, "Add library successfully.")
}

func (c *LibraryController) GetByID(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	l, err := c.libraryService.GetByID(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, l, http.StatusOK)
}

func (c *LibraryController) UpdateName(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}

	var name string
	if err := json.NewDecoder(r.Body).Decode(&name); err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}

	err = c.libraryService.UpdateName(id, name)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonMsg(w, "Updated library name.")
}

func (c *LibraryController) UpdatePath(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}

	var path string
	if err := json.NewDecoder(r.Body).Decode(&path); err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}

	err = c.libraryService.UpdatePath(id, path)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonMsg(w, "Updated library path.")
}

func (c *LibraryController) Scan(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}

	c.scanMutex.Lock()
	if c.scanStatus.Running {
		c.scanMutex.Unlock()
		jsonError(w, "Another scan is already in progress", http.StatusConflict)
		return
	}

	startedAt := time.Now()
	c.scanStatus = ScanStatus{
		Running:   true,
		LibraryID: id,
		Report:    &service.ScanReport{},
		StartedAt: &startedAt,
	}
	startedStatus := c.cloneScanStatusLocked()
	c.scanMutex.Unlock()

	go func() {
		report, err := c.libraryService.Scan(id, func(progress service.ScanReport) {
			c.scanMutex.Lock()
			if c.scanStatus.LibraryID == id {
				progressCopy := progress
				c.scanStatus.Report = &progressCopy
			}
			c.scanMutex.Unlock()
		})

		c.scanMutex.Lock()
		defer c.scanMutex.Unlock()

		finishedAt := time.Now()
		c.scanStatus.Running = false
		c.scanStatus.FinishedAt = &finishedAt
		if report != nil {
			reportCopy := *report
			c.scanStatus.Report = &reportCopy
		}
		if err != nil {
			c.scanStatus.Error = err.Error()
			log.Printf("Scan failed for library %d: %v", id, err)
			return
		}

		c.scanStatus.Error = ""
		log.Printf("Scan completed for library %d: %+v", id, report)
	}()

	jsonResponse(w, startedStatus, http.StatusAccepted)
}

func (c *LibraryController) GetScanStatus(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}

	c.scanMutex.Lock()
	status := c.cloneScanStatusLocked()
	c.scanMutex.Unlock()

	if status.LibraryID != id {
		jsonResponse(w, ScanStatus{LibraryID: id, Report: &service.ScanReport{}}, http.StatusOK)
		return
	}

	jsonResponse(w, status, http.StatusOK)
}

func (c *LibraryController) cloneScanStatusLocked() ScanStatus {
	status := c.scanStatus
	if c.scanStatus.Report != nil {
		reportCopy := *c.scanStatus.Report
		reportCopy.FailedFiles = append([]string(nil), c.scanStatus.Report.FailedFiles...)
		status.Report = &reportCopy
	}
	return status
}

func (c *LibraryController) Delete(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	err = c.libraryService.Delete(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonMsg(w, "Deleted library.")
}

func (c *LibraryController) GetSongs(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	songs, err := c.libraryService.GetSongs(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, songs, http.StatusOK)
}

func (c *LibraryController) GetSongsByArtist(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	songs, err := c.libraryService.GetSongsByArtist(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, songs, http.StatusOK)
}

func (c *LibraryController) GetSongsByAlbum(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	songs, err := c.libraryService.GetSongsByAlbum(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, songs, http.StatusOK)
}

func (c *LibraryController) GetArtists(w http.ResponseWriter, r *http.Request) {
	artists, err := c.libraryService.GetArtists()
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, artists, http.StatusOK)
}

func (c *LibraryController) GetArtist(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	artist, err := c.libraryService.GetArtist(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, artist, http.StatusOK)
}

func (c *LibraryController) GetAlbums(w http.ResponseWriter, r *http.Request) {
	albums, err := c.libraryService.GetAlbums()
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, albums, http.StatusOK)
}

func (c *LibraryController) GetAlbumsByArtist(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	albums, err := c.libraryService.GetAlbumsByArtistWithDetail(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, albums, http.StatusOK)
}

func (c *LibraryController) GetAlbum(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	album, err := c.libraryService.GetAlbum(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	jsonResponse(w, album, http.StatusOK)
}

func (c *LibraryController) GetAlbumCover(w http.ResponseWriter, r *http.Request) {
	idParam := chi.URLParam(r, "id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		jsonError(w, err.Error(), http.StatusBadRequest)
		return
	}
	coverPath, err := c.coverService.GetAlbumCover(id)
	if err != nil {
		jsonError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	http.ServeFile(w, r, coverPath)
}