// kenaito-media-picker 主入口：启动 Web 服务（内嵌前端），媒体库扫描整理由页面点击触发。
package main

import (
	"fmt"
	"io"
	"io/fs"
	"mime"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"time"

	"kenaito-media-picker/frontend"
	"kenaito-media-picker/internal/api"
	"kenaito-media-picker/internal/config"
	"kenaito-media-picker/internal/store"

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

func main() {
	config.LoadAppConfig()
	cfg := config.GetAppConfig()

	// 打开数据库；失败时服务照常启动，仅媒体库查询不可用、扫描不记录信息
	st, err := store.Open(cfg.Dsn)
	if err != nil {
		fmt.Printf("=== 打开数据库失败(媒体库查询不可用): %v\n", err)
		st = nil
	} else {
		defer st.Close()
	}

	r := api.NewRouter(st)
	// 请求日志输出到 stderr，避免占用被扫描流程捕获的 stdout
	r.Use(gin.LoggerWithWriter(os.Stderr))
	r.NoRoute(staticHandler())

	addr := fmt.Sprintf(":%d", cfg.Port)
	url := "http://localhost" + addr
	fmt.Printf("=== Web 服务已启动: %s\n", url)
	fmt.Printf("=== 数据库: %s\n", cfg.Dsn)
	fmt.Printf("=== 在页面上点击【开始扫描】执行媒体整理（会移动文件，注意备份）\n")
	if cfg.AutoOpen {
		go func() {
			time.Sleep(600 * time.Millisecond) // 等服务端口就绪再打开
			openBrowser(url)
		}()
	}
	if err := r.Run(addr); err != nil {
		fmt.Printf("=== 服务启动失败: %v\n", err)
	}
}

// openBrowser 调用系统默认浏览器打开指定 URL（Windows/macOS/Linux）
func openBrowser(url string) {
	var cmd *exec.Cmd
	switch runtime.GOOS {
	case "windows":
		cmd = exec.Command("cmd", "/c", "start", "", url)
	case "darwin":
		cmd = exec.Command("open", url)
	default:
		cmd = exec.Command("xdg-open", url)
	}
	if err := cmd.Start(); err != nil {
		fmt.Printf("=== 自动打开浏览器失败: %v\n", err)
	}
}

// staticHandler 服务内嵌前端产物：命中静态资源则返回，否则回退 index.html（hash 路由）。
func staticHandler() gin.HandlerFunc {
	distFS, err := fs.Sub(frontend.Dist, "dist")
	if err != nil {
		return func(c *gin.Context) {
			c.String(http.StatusNotFound, "前端产物缺失，请先 npm run build 后重新编译")
		}
	}
	return func(c *gin.Context) {
		if strings.HasPrefix(c.Request.URL.Path, "/api") {
			c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "接口不存在", "data": nil})
			return
		}
		path := strings.TrimPrefix(c.Request.URL.Path, "/")
		if path == "" {
			path = "index.html"
		}
		file, err := distFS.Open(path)
		if err != nil {
			file, err = distFS.Open("index.html")
		}
		if err != nil {
			c.String(http.StatusNotFound, "页面不存在")
			return
		}
		defer file.Close()
		info, statErr := file.Stat()
		if statErr != nil {
			c.String(http.StatusInternalServerError, "读取前端资源失败")
			return
		}
		if rs, ok := file.(io.ReadSeeker); ok {
			http.ServeContent(c.Writer, c.Request, info.Name(), info.ModTime(), rs)
			return
		}
		body, err := io.ReadAll(file)
		if err != nil {
			c.String(http.StatusInternalServerError, "读取前端资源失败")
			return
		}
		c.Data(http.StatusOK, mime.TypeByExtension(filepath.Ext(path)), body)
	}
}