package public

import (
	"FileRelay/internal/api/middleware"
	"FileRelay/internal/bootstrap"
	"FileRelay/internal/model"
	"FileRelay/internal/service"
	"FileRelay/internal/storage"
	"archive/zip"
	"fmt"
	"io"
	"net/http"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
)

type PickupResponse struct {
	Remark        string           `json:"remark"`
	ExpireAt      *time.Time       `json:"expire_at"`
	ExpireType    string           `json:"expire_type"`
	DownloadCount int              `json:"download_count"`
	MaxDownloads  int              `json:"max_downloads"`
	Type          string           `json:"type"`
	Content       string           `json:"content,omitempty"`
	Files         []model.FileItem `json:"files,omitempty"`
}

// DownloadBatch 批量下载文件 (ZIP)
// @Summary      批量下载文件
// @Description  根据取件码将批次内的所有文件打包为 ZIP 格式一次性下载。可选提供带 pickup scope 的 API Token。
// @Tags         Public
// @Security     APITokenAuth
// @Param        pickup_code  path  string  true  "取件码"
// @Produce      application/zip
// @Success      200  {file}    file
// @Failure      404  {object}  model.Response
// @Router       /api/batches/{pickup_code}/download [get]
func (h *PickupHandler) DownloadBatch(c *gin.Context) {
	code := c.Param("pickup_code")
	batch, err := h.batchService.GetBatchByPickupCode(code)
	if err != nil {
		c.JSON(http.StatusNotFound, model.ErrorResponse(model.CodeNotFound, "batch not found or expired"))
		return
	}

	c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=\"batch_%s.zip\"", code))
	c.Header("Content-Type", "application/zip")

	zw := zip.NewWriter(c.Writer)
	defer zw.Close()

	for _, item := range batch.FileItems {
		reader, err := storage.GlobalStorage.Open(c.Request.Context(), item.StoragePath)
		if err != nil {
			continue // Skip failed files
		}

		f, err := zw.Create(item.OriginalName)
		if err != nil {
			reader.Close()
			continue
		}

		_, _ = io.Copy(f, reader)
		reader.Close()
	}

	// 增加下载次数
	if err := h.batchService.IncrementDownloadCount(batch.ID); err != nil {
		fmt.Printf("[DownloadBatch] Failed to increment download count for batch %s: %v\n", batch.ID, err)
	}
}

type PickupHandler struct {
	batchService *service.BatchService
}

func NewPickupHandler() *PickupHandler {
	return &PickupHandler{
		batchService: service.NewBatchService(),
	}
}

// Pickup 获取批次信息
// @Summary      获取批次信息
// @Description  根据取件码获取文件批次详细信息和文件列表。可选提供带 pickup scope 的 API Token。
// @Tags         Public
// @Security     APITokenAuth
// @Produce      json
// @Param        pickup_code  path  string  true  "取件码"
// @Success      200  {object}  model.Response{data=PickupResponse}
// @Failure      404  {object}  model.Response
// @Router       /api/batches/{pickup_code} [get]
func (h *PickupHandler) Pickup(c *gin.Context) {
	code := c.Param("pickup_code")
	if code == "" {
		c.JSON(http.StatusBadRequest, model.ErrorResponse(model.CodeBadRequest, "pickup code required"))
		return
	}

	batch, err := h.batchService.GetBatchByPickupCode(code)
	if err != nil {
		middleware.RecordPickupFailure(c.ClientIP(), code)
		c.JSON(http.StatusNotFound, model.ErrorResponse(model.CodeNotFound, "batch not found or expired"))
		return
	}

	if batch.Type == "text" {
		if err := h.batchService.IncrementDownloadCount(batch.ID); err != nil {
			fmt.Printf("[Pickup] Failed to increment download count for batch %s: %v\n", batch.ID, err)
		} else {
			batch.DownloadCount++
		}
	}

	c.JSON(http.StatusOK, model.SuccessResponse(PickupResponse{
		Remark:        batch.Remark,
		ExpireAt:      batch.ExpireAt,
		ExpireType:    batch.ExpireType,
		DownloadCount: batch.DownloadCount,
		MaxDownloads:  batch.MaxDownloads,
		Type:          batch.Type,
		Content:       batch.Content,
		Files:         batch.FileItems,
	}))
}

// DownloadFile 下载单个文件
// @Summary      下载单个文件
// @Description  根据文件 ID 下载单个文件。可选提供带 pickup scope 的 API Token。
// @Tags         Public
// @Security     APITokenAuth
// @Param        file_id  path  string  true  "文件 ID (UUID)"
// @Produce      application/octet-stream
// @Success      200  {file}    file
// @Failure      404  {object}  model.Response
// @Failure      410  {object}  model.Response
// @Router       /api/files/{file_id}/download [get]
func (h *PickupHandler) DownloadFile(c *gin.Context) {
	fileID := c.Param("file_id")

	var item model.FileItem
	if err := bootstrap.DB.First(&item, "id = ?", fileID).Error; err != nil {
		c.JSON(http.StatusNotFound, model.ErrorResponse(model.CodeNotFound, "file not found"))
		return
	}

	var batch model.FileBatch
	if err := bootstrap.DB.First(&batch, "id = ?", item.BatchID).Error; err != nil {
		c.JSON(http.StatusNotFound, model.ErrorResponse(model.CodeNotFound, "batch not found"))
		return
	}

	if h.batchService.IsExpired(&batch) {
		h.batchService.MarkAsExpired(&batch)
		c.JSON(http.StatusGone, model.ErrorResponse(model.CodeGone, "batch expired"))
		return
	}

	// 打开文件
	reader, err := storage.GlobalStorage.Open(c.Request.Context(), item.StoragePath)
	if err != nil {
		c.JSON(http.StatusInternalServerError, model.ErrorResponse(model.CodeInternalError, "failed to open file"))
		return
	}
	defer reader.Close()

	// 增加下载次数
	if err := h.batchService.IncrementDownloadCount(batch.ID); err != nil {
		// 记录错误但不中断下载过程
		fmt.Printf("[Download] Failed to increment download count for batch %s: %v\n", batch.ID, err)
	}

	c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", item.OriginalName))
	c.Header("Content-Type", item.MimeType)
	c.Header("Content-Length", strconv.FormatInt(item.Size, 10))

	// 如果是 HEAD 请求，只返回 Header
	if c.Request.Method == http.MethodHead {
		return
	}

	io.Copy(c.Writer, reader)
}