package main

import (
	"bufio"
	_ "embed"
	"flag"
	"fmt"
	"html/template"
	"io/fs"
	"log"
	"net/http"
	"os"
	"os/exec"
	"path"
	"strings"
	"time"

	"gitlab.com/balki/ytui/db"
)

//go:embed templates/index.html
var page string

const port = 8080

var (
	ytdlCmd         = []string{"youtube-dl"}
	videosPath      = "./vids"
	cachePath       = "./cache"
	dbPath          = "./db.json"
	approval   bool = false
)

var d *db.Db

func parse() {
	ytcmd := ytdlCmd[0]
	flag.StringVar(&ytcmd, "ytdlcmd", ytcmd, "youtube-dl command seperated by spaces")
	flag.StringVar(&videosPath, "videospath", videosPath, "Path where videos are saved")
	flag.StringVar(&cachePath, "cachepath", cachePath, "Path where temporary download files are saved")
	flag.StringVar(&dbPath, "datapath", dbPath, "Path where downloaded info is saved")
	flag.BoolVar(&approval, "approval", approval, "Is approval required before allowing to watch")
	flag.Parse()
	if ytcmd != ytdlCmd[0] {
		ytdlCmd = strings.Fields(ytcmd)
	}
}

func main() {
	fmt.Println("vim-go")
	parse()
	tmpl, err := template.New("page").Parse(page)
	if err != nil {
		panic(err)
	}
	d, err = db.Load(dbPath)
	if err != nil {
		panic(err)
	}
	defer d.Save()
	seen := map[string]struct{}{}
	d.Run(func(d *db.Jdb) {
		for _, i := range d.Items {
			seen[i.URL] = struct{}{}
		}
	})
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodGet {
			d.Run(func(d *db.Jdb) {
				if err := tmpl.Execute(w, d); err != nil {
					panic(err)
				}
			})
			return
		}
		if err := r.ParseForm(); err != nil {
			panic(err)
		}
		yturl := r.PostFormValue("youtube_url")
		if yturl == "" {
			panic("yturl empty")
		}
		if _, ok := seen[yturl]; !ok {
			seen[yturl] = struct{}{}
			id := d.Add(db.Item{
				Date:     time.Now().String(),
				URL:      yturl,
				Title:    "Loading",
				Approved: false,
				Status:   db.NotStarted,
			})
			go getTitle(id, yturl)
			go download(id, yturl)

		}
		http.Redirect(w, r, "/", http.StatusSeeOther)
	})
	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%v", port), nil))
}

func getTitle(id int, yturl string) {
	args := append(ytdlCmd, "--get-title", yturl)
	cmd := exec.Command(args[0], args[1:]...)
	op, err := cmd.Output()
	if err != nil {
		panic(err)
	}
	d.Update(id, true, func(i *db.Item) {
		i.Title = string(op)
	})
}

func download(id int, yturl string) {
	d.Update(id, true, func(i *db.Item) {
		i.Status = db.InProgress
	})
	pathTmpl := fmt.Sprintf("%s/video_%d.%%(ext)s", cachePath, id)
	args := append(ytdlCmd, "--newline", "--output", pathTmpl, yturl)
	cmd := exec.Command(args[0], args[1:]...)
	rc, err := cmd.StdoutPipe()
	if err != nil {
		log.Panic(err)
	}
	if err := cmd.Start(); err != nil {
		log.Panic(err)
	}
	br := bufio.NewReader(rc)
	for {
		line, _, err := br.ReadLine()
		if err != nil {
			break
		}
		d.Update(id, false, func(i *db.Item) {
			i.Progress = string(line)
		})
	}
	rc.Close()
	err = cmd.Wait()
	var status db.DownloadStatus
	var fname string
	if err != nil {
		status = db.Error
	} else {
		status = db.Done
		matches, err := fs.Glob(os.DirFS(cachePath), fmt.Sprintf("video_%d.*", id))
		if err != nil {
			panic(err)
		}
		if len(matches) != 1 {
			panic(len(matches))
		}
		fname = matches[0]
		err = os.Rename(path.Join(cachePath, fname), path.Join(videosPath, fname))
		if err != nil {
			panic(err)
		}
	}
	d.Update(id, true, func(i *db.Item) {
		i.Status = status
		i.FileName = fname
	})
}