package main

import (
	"bytes"
	"fmt"
	"io/fs"
	"log"
	"os/exec"
	"path/filepath"
	"sort"
	"strconv"
	"strings"
)

// Category 电影分类结构
type Category struct {
	Name   string  `json:"name"`
	Movies []Movie `json:"movies"`
}

// Movie 电影结构
type Movie struct {
	Name     string `json:"filename"`
	Image    string `json:"image"`
	Duration int    `json:"duration"`
}

// var movies []Movie
var categories []Category

var IsRemakePNG = false

func initMovie() {
	// 需要改进 如果存在这个文件的略缩图, 就不存进movieDict里
	var movieDict map[string]*Movie = make(map[string]*Movie)

	matches, err := filepath.Glob("movie/*")
	if err != nil {
		log.Println(err)
	}

	for _, filename := range matches {
		base := filepath.Base(filename)

		// ext := filepath.Ext(base)
		base = base[:strings.IndexByte(base, '.')]

		if _, ok := movieDict[base]; ok {
			if !IsRemakePNG {
				delete(movieDict, base)
			}
		} else {
			movieDict[base] = &Movie{Name: filename}
		}

	}

	// 初始化分类
	categories = []Category{
		{Name: "15min", Movies: []Movie{}},
		{Name: "30min", Movies: []Movie{}},
		{Name: "60min", Movies: []Movie{}},
		{Name: "大于60min", Movies: []Movie{}},
	}

	filepath.Walk("./movie", func(path string, info fs.FileInfo, err error) error {
		if !info.IsDir() && filepath.Ext(info.Name()) != ".png" {
			base := info.Name()
			cmd := exec.Command("ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries", "stream=duration", "-of", "default=nw=1:nk=1", "./movie/"+info.Name())
			durationOutput, err := cmd.Output()
			if err != nil {
				log.Printf("Error getting duration for %s: %v", info.Name(), err)
				return err
			}

			duration, err := strconv.ParseFloat(strings.Trim(string(durationOutput), "\n "), 64)
			if err != nil {
				log.Printf("Error parsing duration for %s: %v", info.Name(), err)
				return err
			}
			// log.Println(path, info.Name())

			movie := Movie{
				Name:     info.Name(),
				Image:    base[:strings.IndexByte(base, '.')] + ".png",
				Duration: int(duration / 60.0),
			}

			if m, ok := movieDict[base[:strings.IndexByte(base, '.')]]; ok {
				m.Duration = movie.Duration
			}

			if movie.Duration <= 15 {
				categories[0].Movies = append(categories[0].Movies, movie)
			} else if movie.Duration <= 30 {
				categories[1].Movies = append(categories[1].Movies, movie)
			} else if movie.Duration <= 60 {
				categories[2].Movies = append(categories[2].Movies, movie)
			} else {
				categories[3].Movies = append(categories[3].Movies, movie)
			}

		}
		return nil
	})

	for _, category := range categories {
		var movies = category.Movies
		sort.Slice(movies, func(i, j int) bool {
			return movies[i].Duration < movies[j].Duration
		})
	}

	for key, movie := range movieDict {
		// width := 160
		// height := 120
		// if movie.Duration <= 40 {
		// 	continue
		// }

		log.Println(movie.Name, "时长:", movie.Duration)
		var filter string

		if movie.Duration <= 2 {
			filter = "select='isnan(prev_selected_t)+gte(t-prev_selected_t\\,5)',scale=320:180,tile=3x3"
		} else if movie.Duration <= 5 {
			filter = "select='isnan(prev_selected_t)+gte(t-prev_selected_t\\,10)',scale=320:180,tile=3x3"
		} else if movie.Duration <= 30 {
			filter = "select='isnan(prev_selected_t)+gte(t-prev_selected_t\\,20)',scale=320:180,tile=3x3"
		} else if movie.Duration <= 60 {
			filter = "select='isnan(prev_selected_t)+gte(t-prev_selected_t\\,35)',scale=320:180,tile=3x3"
		} else {
			filter = "select='isnan(prev_selected_t)+gte(t-prev_selected_t\\,60)',scale=320:180,tile=3x3"
		}

		cmd := exec.Command("ffmpeg",
			"-i", movie.Name,
			"-vf", filter,
			"-frames:v", "1",
			"-y",
			"movie/"+key+".png",
		)

		var buffer bytes.Buffer
		cmd.Stdout = &buffer
		if cmd.Run() != nil {
			log.Println(buffer.String())
			panic(fmt.Errorf("could not generate frame %s %d", movie.Name, movie.Duration))
		}

	}

	// log.Printf("%##v", categories)
}