package router

import (
	"encoding/json"
	"fmt"
	"net/http"
	"os/exec"
	"runtime"
	"strconv"

	"bilidown/internal/task"
	"bilidown/internal/util"
)

func createTask(w http.ResponseWriter, r *http.Request) {
	defer r.Body.Close()
	if r.Method != http.MethodPost {
		util.Res{Success: false, Message: "不支持的请求方法"}.Write(w)
		return
	}
	var body []task.TaskInDB
	err := json.NewDecoder(r.Body).Decode(&body)
	if err != nil {
		util.Res{Success: false, Message: "参数错误"}.Write(w)
		return
	}
	db := util.MustGetDB()
	defer db.Close()

	// 预先获取下载目录，避免循环中重复查询
	folder, err := util.GetCurrentFolder(db)
	if err != nil {
		util.Res{Success: false, Message: fmt.Sprintf("获取下载目录失败: %v", err)}.Write(w)
		return
	}

	for _, item := range body {
		if !util.CheckBvidFormat(item.Bvid) {
			util.Res{Success: false, Message: "bvid 格式错误"}.Write(w)
			return
		}
		if item.Cover == "" || item.Title == "" || item.Owner == "" {
			util.Res{Success: false, Message: "参数错误"}.Write(w)
			return
		}

		if !util.IsValidURL(item.Cover) {
			util.Res{Success: false, Message: "封面链接格式错误"}.Write(w)
			return
		}
		if !util.IsValidURL(item.Audio) {
			util.Res{Success: false, Message: "音频链接格式错误"}.Write(w)
			return
		}
		if !util.IsValidURL(item.Video) {
			util.Res{Success: false, Message: "视频链接格式错误"}.Write(w)
			return
		}
		if !util.IsValidFormatCode(item.Format) {
			util.Res{Success: false, Message: "清晰度代码错误"}.Write(w)
			return
		}
		item.Folder = folder
		item.Status = "waiting"
		_task := task.Task{TaskInDB: item}
		_task.Title = util.FilterFileName(_task.Title)
		err = _task.Create(db)
		if err != nil {
			util.Res{Success: false, Message: fmt.Sprintf("_task.Create: %v.", err)}.Write(w)
			return
		}
		go _task.Start()
	}
	util.Res{Success: true, Message: "创建成功"}.Write(w)
}

func getActiveTask(w http.ResponseWriter, r *http.Request) {
	util.Res{Success: true, Data: task.GlobalTaskList}.Write(w)
}

func getTaskList(w http.ResponseWriter, r *http.Request) {
	err := r.ParseForm()
	if err != nil {
		util.Res{Success: false, Message: "参数错误"}.Write(w)
		return
	}
	db := util.MustGetDB()
	defer db.Close()
	page, err := strconv.Atoi(r.FormValue("page"))
	if err != nil {
		page = 0
	}
	pageSize, err := strconv.Atoi(r.FormValue("pageSize"))
	if err != nil {
		pageSize = 360
	}
	tasks, err := task.GetTaskList(db, page, pageSize)
	if err != nil {
		util.Res{Success: false, Message: err.Error()}.Write(w)
		return
	}
	util.Res{Success: true, Message: "获取成功", Data: tasks}.Write(w)
}

// showFile 调用 Explorer 查看文件位置
func showFile(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		util.Res{Success: false, Message: "参数错误"}.Write(w)
		return
	}
	filePath := r.FormValue("filePath")

	var cmd *exec.Cmd

	// 根据操作系统选择命令
	switch runtime.GOOS {
	case "windows":
		// Windows 使用 explorer
		cmd = exec.Command("explorer", "/select,", filePath)
	case "darwin":
		// macOS 使用 open
		cmd = exec.Command("open", "-R", filePath)
	case "linux":
		// Linux 使用 xdg-open
		cmd = exec.Command("xdg-open", filePath)
	default:
		util.Res{Success: false, Message: "不支持的操作系统"}.Write(w)
		return
	}
	err := cmd.Start()
	if err != nil {
		util.Res{Success: false, Message: err.Error()}.Write(w)
		return
	}
	util.Res{Success: true, Message: "操作成功"}.Write(w)
}

func deleteTask(w http.ResponseWriter, r *http.Request) {
	// 支持单个删除（GET 参数 id）和批量删除（POST 参数 ids）
	var taskIDs []int

	if r.Method == http.MethodPost {
		defer r.Body.Close()
		var body struct {
			IDs []int `json:"ids"`
		}
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
			util.Res{Success: false, Message: "参数错误"}.Write(w)
			return
		}
		taskIDs = body.IDs
	} else {
		taskIDStr := r.FormValue("id")
		taskID, err := strconv.Atoi(taskIDStr)
		if err != nil {
			util.Res{Success: false, Message: "参数错误"}.Write(w)
			return
		}
		taskIDs = []int{taskID}
	}

	if len(taskIDs) == 0 {
		util.Res{Success: false, Message: "参数错误"}.Write(w)
		return
	}

	db := util.MustGetDB()
	defer db.Close()

	// 批量删除结果
	successCount := 0
	failedTasks := []struct {
		ID    int
		Error string
	}{}

	for _, taskID := range taskIDs {
		// 只删除数据库记录，不删除已下载的视频文件
		err := task.DeleteTask(db, taskID)
		if err != nil {
			failedTasks = append(failedTasks, struct {
				ID    int
				Error string
			}{ID: taskID, Error: fmt.Sprintf("数据库删除失败: %v", err)})
			continue
		}
		successCount++
	}

	if len(failedTasks) == 0 {
		util.Res{Success: true, Message: fmt.Sprintf("成功删除 %d 个任务", successCount)}.Write(w)
	} else {
		util.Res{
			Success: successCount > 0,
			Message: fmt.Sprintf("成功删除 %d 个任务，失败 %d 个", successCount, len(failedTasks)),
			Data:    failedTasks,
		}.Write(w)
	}
}

func cancelTask(w http.ResponseWriter, r *http.Request) {
	// 支持单个取消（GET 参数 id）和批量取消（POST 参数 ids）
	var taskIDs []int64

	if r.Method == http.MethodPost {
		defer r.Body.Close()
		var body struct {
			IDs []int64 `json:"ids"`
		}
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
			util.Res{Success: false, Message: "参数错误"}.Write(w)
			return
		}
		taskIDs = body.IDs
	} else {
		taskIDStr := r.FormValue("id")
		taskID, err := strconv.ParseInt(taskIDStr, 10, 64)
		if err != nil {
			util.Res{Success: false, Message: "参数错误"}.Write(w)
			return
		}
		taskIDs = []int64{taskID}
	}

	if len(taskIDs) == 0 {
		util.Res{Success: false, Message: "参数错误"}.Write(w)
		return
	}

	// 批量取消结果
	successCount := 0
	failedIDs := []int64{}

	for _, taskID := range taskIDs {
		if task.CancelTask(taskID) {
			successCount++
		} else {
			failedIDs = append(failedIDs, taskID)
		}
	}

	if len(failedIDs) == 0 {
		util.Res{Success: true, Message: fmt.Sprintf("成功取消 %d 个任务", successCount)}.Write(w)
	} else {
		util.Res{
			Success: successCount > 0,
			Message: fmt.Sprintf("成功取消 %d 个任务，失败 %d 个", successCount, len(failedIDs)),
			Data:    failedIDs,
		}.Write(w)
	}
}