package admin

import (
	"context"
	"log/slog"
	"net/http"
	"path/filepath"
	"server/internal/config"
	"server/internal/model/common"
	"server/internal/model/request"
	"server/internal/pkg/errs"
	"server/internal/pkg/httputil"
	"server/internal/pkg/safego"
	"server/internal/pkg/validator"
	"server/internal/router"
	"server/internal/service/admin"
	"strings"

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

type FileHandler struct {
	service *admin.FileService
	logger  *slog.Logger
	cfg     *config.Config
}

var _ router.Registrar = (*FileHandler)(nil)

func NewFileHandler(service *admin.FileService, logger *slog.Logger, cfg *config.Config) *FileHandler {
	return &FileHandler{
		service: service,
		logger:  logger,
		cfg:     cfg,
	}
}

func (h *FileHandler) Register(r chi.Router) {
	r.Route("/files", func(r chi.Router) {
		r.Get("/", h.List)
		r.Post("/", h.Upload)
		r.Post("/sync-metadata", h.SyncMetadata)
	})
}

func (h *FileHandler) List(w http.ResponseWriter, r *http.Request) {
	pagination := httputil.Pagination(r)

	result, err := h.service.List(r.Context(), pagination)
	if err != nil {
		httputil.Fail(w, err)
		return
	}

	resp := common.PageResponse{
		Page:     pagination.Page,
		PageSize: pagination.PageSize,
		List:     result.List,
		Total:    result.Total,
	}

	httputil.OkWithPage(w, &resp)
}

func (h *FileHandler) Upload(w http.ResponseWriter, r *http.Request) {
	// 限制上传大小（默认 10MB）
	maxSize := h.cfg.File.MaxUploadSize
	if maxSize <= 0 {
		maxSize = 10 << 20 // 10MB
	}
	r.Body = http.MaxBytesReader(w, r.Body, maxSize)

	folder := r.FormValue("folder")
	req := request.UploadFileRequest{Folder: folder}
	if err := validator.Struct(&req); err != nil {
		httputil.Fail(w, err)
		return
	}

	_, header, err := r.FormFile("file")
	if err != nil {
		httputil.Fail(w, err)
		return
	}

	// 扩展名白名单
	ext := strings.ToLower(filepath.Ext(header.Filename))
	if !request.IsAllowedUploadExt(ext) {
		httputil.Fail(w, errs.ErrFileTypeNotAllowed)
		return
	}

	file, err := h.service.Upload(r.Context(), folder, header)
	if err != nil {
		httputil.Fail(w, err)
		return
	}

	httputil.Ok(w, file)
}

func (h *FileHandler) SyncMetadata(w http.ResponseWriter, r *http.Request) {
	safego.Go(func() {
		if err := h.service.SyncMetadata(context.Background()); err != nil {
			h.logger.Error("sync metadata failed", "error", err)
		}
	})

	httputil.Ok(w)
}