package main

import (
    "fmt"
    "log"
    "regexp"
    "context"
    "io"
    "bytes"

    "github.com/bwmarrin/discordgo"
    "github.com/wader/goutubedl"
    "mvdan.cc/xurls/v2" // Peak lazy
)

const MaxSize = 10*1024*1024

// This function will be called every time a new message is created on any channel that the authenticated bot has access to.
func messageCreate(session *discordgo.Session, message *discordgo.MessageCreate) {
    // Ignore all messages created by the bot itself
    if message.Author.ID == session.State.User.ID {
        return
    }

    //log.Printf("[%s] %s#%s: %s", message.ID, message.Author.Username, message.Author.Discriminator, message.Content)

    rxStrict := xurls.Strict()
    urls := rxStrict.FindAllString(message.Content, -1)
    if len(urls) > 0 {
        response := discordgo.MessageSend {
            Content: "Woah there partner! I detect some services that aren't very privacy friendly. Let me help you with that!",
            Reference: message.Reference(),
            Files: []*discordgo.File{},
        }

        log.Printf("Message %s has URLs!", message.ID)

        respond := false

        for _, url := range urls {
            if output, _ := regexp.MatchString("(http.*twitter.com/.*/status)|(http.*t.co/.*)|(http.*x.com/.*/status)", url); output {
                log.Println("Cringe twitter post detected.")

                if shortned, _ := regexp.MatchString("http.*t.co/.*", url); shortned {
                    var err error

                    log.Println("Short URL detected. Getting long version.")
                    url, err = getRedirectURL(url)
                    if err != nil {
                        log.Println(err)
                        continue
                    }
                }

                response.Content = response.Content + fmt.Sprintf("\n<%s>", regexp.MustCompile("(http.*twitter.com)|(http.*x.com)").ReplaceAllString(url, "https://nitter.poast.org"))

                result, err := goutubedl.New(context.Background(), url, goutubedl.Options{})
                if err != nil {
                    // If it's complaining due to a lack of videos, don't care.
                    if noVideo, _ := regexp.MatchString(".*No video could be found in this tweet*", err.Error()); noVideo {
                        respond = true
                    } else {
                        log.Println(err)
                    }

                    continue
                } else {
                    choice, err := getLargestFormat(result, MaxSize)
                    log.Printf("Choice: %s | Size: %fM\n", choice.FormatID, choice.FilesizeApprox/1024/1024)
                    if err == nil {
                        session.ChannelTyping(message.ChannelID)
                        downloadResult, err := result.Download(context.Background(), choice.FormatID)
                        if err != nil {
                            log.Println(err)
                            //session.ChannelMessageSend(message.ChannelID, err.Error())
                            continue
                        }

                        response.Files = append(response.Files, &discordgo.File {
                            Name: fmt.Sprintf("%s.%s", result.Info.ID, choice.Ext),
                            ContentType: "text/plain", // This is of course not true, but Discord doesn't give a shit
                            Reader: downloadResult,
                        })

                        defer downloadResult.Close()
                    } else {
                        log.Println(err)
                    }
                }

                respond = true
            } else if output, _ := regexp.MatchString("(http.*youtube.com/watch.*?v=.*)|(http.*youtube.com/shorts/.*)|(http.*youtube.com/v/.*)|(http.*youtu.be/.*)", url); output {
                log.Println("YouTube detected.")

                if shortned, _ := regexp.MatchString("(http.*youtu\\.be/.*)|(http.*youtube.com/v/.*)", url); shortned {
                    var err error

                    log.Println("Short URL detected. Getting long version.")
                    url, err = getRedirectURL(url)
                    if err != nil {
                        log.Println(err)
                        continue
                    }
                }

                response.Content = response.Content + fmt.Sprintf("\n<%s>", regexp.MustCompile("http.*youtube\\.com").ReplaceAllString(url, "https://piped.video"))

                result, err := goutubedl.New(context.Background(), url, goutubedl.Options{})
                if err != nil {
                    log.Println(err)
                    continue
                } else if result.Info.AgeLimit < 18 && ! result.Info.IsLive {
                    /*
                    videoChoice, audioChoice, err := getLargestDashFormat(result, MaxSize)
                    log.Printf("Choice: %s+%s | Size: %fM\n", videoChoice.FormatID, audioChoice.FormatID, (videoChoice.Filesize+audioChoice.Filesize)/1024/1024)
                    if err == nil {
                        downloadResult, err := result.Download(context.Background(), fmt.Sprintf("%s+%s", videoChoice.FormatID, audioChoice.FormatID))
                    */
                    choice, err := getLargestYTFormat(result, MaxSize)
                    log.Printf("Choice: %s | Size: %fM\n", choice.FormatID, choice.FilesizeApprox/1024/1024)
                    if err == nil {
                        session.ChannelTyping(message.ChannelID)
                        downloadResult, err := result.Download(context.Background(), choice.FormatID)

                        if err != nil {
                            log.Println(err)
                            //session.ChannelMessageSend(message.ChannelID, err.Error())
                            continue
                        }

                        response.Files = append(response.Files, &discordgo.File {
                            //Name: fmt.Sprintf("%s.%s", result.Info.ID, videoChoice.Ext),
                            Name: fmt.Sprintf("%s.%s", result.Info.ID, choice.Ext),
                            ContentType: "text/plain", // This is of course not true, but Discord doesn't give a shit
                            Reader: downloadResult,
                        })

                        defer downloadResult.Close()
                    } else {
                        log.Println(err)
                    }
                }

                respond = true
            } else if output, _ := regexp.MatchString("(http.*instagram\\.com/p/.*)|(http.*instagram\\.com/tv/.*)|(http.*instagram\\.com/reel/.*)", url); output {
                log.Println("Instagram detected.")

                response.Content = response.Content + fmt.Sprintf("\n%s", regexp.MustCompile("http.*instagram\\.com").ReplaceAllString(url, "https://bibliogram.art"))

                result, err := goutubedl.New(context.Background(), url, goutubedl.Options{})
                if err != nil {
                    log.Println(err)
                    continue
                } else {
                    session.ChannelTyping(message.ChannelID)
                    downloadResult, err := result.Download(context.Background(), "best") // Insta only has one possible format to download :(
                    if err != nil {
                        log.Println(err)
                        continue
                    }


                    // Test to see if the result is more than 8MB through the tried and true method of downloading it into a 8MB slice and seeing if it errors out
                    var buf = make([]byte, MaxSize + 1)
                    size, err := io.ReadFull(downloadResult, buf)

                    // This section is probably really bad, don't copy it. Actually, don't even look at it.
                    if size <= MaxSize && err.Error() == "unexpected EOF" {
                        log.Printf("Video Size: %fM", float64(size)/1024/1024)

                        var newBuf = make([]byte, size)
                        _, err := io.ReadFull(bytes.NewReader(buf), newBuf)
                        if err != nil {
                            log.Println(err)
                            continue
                        }
                        buf = nil

                        response.Files = append(response.Files, &discordgo.File {
                            Name: fmt.Sprintf("%s.%s", result.Info.ID, result.Formats()[0].Ext),
                            ContentType: "text/plain", // This is of course not true, but Discord doesn't give a shit
                            Reader: bytes.NewReader(newBuf),
                        })
                    }

                    downloadResult.Close()
                }

                respond = true
            } else if output, _ := regexp.MatchString("(http.*tiktok\\.com/\\@.*)", url); output {
                log.Println("TikTok detected.")

                response.Content = response.Content + fmt.Sprintf("\n<%s>", regexp.MustCompile("http.*tiktok\\.com").ReplaceAllString(url, "https://proxitok.pussthecat.org"))

                result, err := goutubedl.New(context.Background(), url, goutubedl.Options{})
                if err != nil {
                    log.Println(err)
                    continue
                } else {
                    choice, err := getLargestFormat(result, MaxSize)
                    log.Printf("Choice: %s | Size: %fM\n", choice.FormatID, choice.Filesize/1024/1024)
                    if err == nil {
                        session.ChannelTyping(message.ChannelID)
                        downloadResult, err := result.Download(context.Background(), choice.FormatID)
                        if err != nil {
                            log.Println(err)
                            //session.ChannelMessageSend(message.ChannelID, err.Error())
                            continue
                        }

                        response.Files = append(response.Files, &discordgo.File {
                            Name: fmt.Sprintf("%s.%s", result.Info.ID, choice.Ext),
                            ContentType: "text/plain", // This is of course not true, but Discord doesn't give a shit
                            Reader: downloadResult,
                        })

                        defer downloadResult.Close()
                    } else {
                        log.Println(err)
                    }
                }

                respond = true
            } else if output, _ := regexp.MatchString("(http.*reddit\\.com/r/\\.*)", url); output {
                log.Println("Reddit detected.")

                response.Content = response.Content + fmt.Sprintf("\n<%s>", regexp.MustCompile("http.*reddit\\.com").ReplaceAllString(url, "https://libreddit.privacydev.net"))

                // Reddit's native format is 'mpegts', which Discord cannot preview. This code however does produce a usable video with audio.
                /*
                result, err := goutubedl.New(context.Background(), url, goutubedl.Options{})
                if err != nil {
                    // If it's complaining due to a lack of videos, don't care.
                    if noVideo, _ := regexp.MatchString(".*No media found.*", err.Error()); noVideo {
                        respond = true
                    } else {
                        log.Println(err)
                    }

                    continue
                } else {
                    videoChoice, audioChoice, err := getLargestDashFormat(result, MaxSize)
                    log.Printf("Choice: %s+%s | Size: %fM\n", videoChoice.FormatID, audioChoice.FormatID, (videoChoice.FilesizeApprox+audioChoice.FilesizeApprox)/1024/1024)
                    if err == nil {
                        session.ChannelTyping(message.ChannelID)
                        downloadResult, err := result.Download(context.Background(), fmt.Sprintf("%s+%s", videoChoice.FormatID, audioChoice.FormatID))
                        if err != nil {
                            log.Println(err)
                            //session.ChannelMessageSend(message.ChannelID, err.Error())
                            continue
                        }

                        response.Files = append(response.Files, &discordgo.File {
                            Name: fmt.Sprintf("%s.%s", result.Info.ID, videoChoice.Ext),
                            ContentType: "text/plain", // This is of course not true, but Discord doesn't give a shit
                            Reader: downloadResult,
                        })

                        defer downloadResult.Close()
                    } else {
                        log.Println(err)
                    }
                }
                */

                respond = true
            } else if output, _ := regexp.MatchString("(http.*clips\\.twitch\\.tv/\\.*)", url); output {
                //TODO: Finish
                //Twitch doesn't report filesize (makes too much sense I guess).
                log.Println("Twitch clip detected.")
            }
        }

        if respond {
            if result, err := session.ChannelMessageSendComplex(message.ChannelID, &response); err != nil {
                log.Println(result)
                log.Println(err)
            } else {
                log.Printf("Successfully responded to %s", message.ID)
            }
        }
    }
}