use poise::serenity_prelude as serenity;
use tracing::{error, info};

use super::autocomplete::audio_file;
use crate::Data;
use crate::copyparty::{html_decode, percent_decode};
use crate::error::{Error, Result};
use crate::lang;

type Context<'a> = poise::Context<'a, Data, Error>;

// ── Source classification ──────────────────────────────────────────

/// What kind of audio source are we dealing with?
///
/// This mirrors the Python original's split: `EXTERNAL_URL_PATTERN`
/// (youtube/soundcloud/bandcamp) goes through yt-dlp download, while
/// *every other* URL is streamed directly via ffmpeg (radio, HLS,
/// playlists, direct media files).
#[derive(Debug, Clone, PartialEq)]
enum SourceKind {
    /// YouTube, SoundCloud, Twitch, Bandcamp — platforms that don't serve
    /// raw audio at a direct URL. Needs yt-dlp to extract + download the
    /// media to memory before decoding.
    YtDlp,
    /// Any HTTP(S) URL: internet radio (Icecast/Shoutcast), HLS `.m3u8`,
    /// `.m3u`/`.pls` playlists, Copyparty files, Discord attachments, or
    /// directly-accessible media files. Streamed via an ffmpeg subprocess
    /// — NO full download. ffmpeg handles playlist parsing, Icecast
    /// metadata, reconnection, and codec/container detection universally.
    Stream,
}

/// Play music from Copyparty, URL, or file upload
#[poise::command(slash_command)]
pub async fn grajcuj(
    ctx: Context<'_>,
    #[description = "Plik do odtworzenia"]
    #[autocomplete = "audio_file"]
    melodia: Option<String>,
    #[description = "Bezpośredni plik z twojego systemu"] file: Option<serenity::Attachment>,
    #[description = "Chujowa kompresja!?"] compressed: Option<bool>,
) -> Result<()> {
    let compressed = compressed.unwrap_or(false);
    eprintln!(
        "[DEBUG] play() reached, melodia={:?}, file={:?}, compressed={compressed}",
        melodia,
        file.as_ref().map(|f| &f.filename)
    );
    let result = play_impl(ctx, melodia, file, compressed).await;
    if let Err(e) = &result {
        eprintln!("[DEBUG] play() error: {e}");
        error!("play command failed: {e}");
    }
    result
}

struct ResolvedSource {
    url: String,
    display_name: String,
    kind: SourceKind,
}

fn clean_name(raw: &str) -> String {
    html_decode(&percent_decode(raw))
}

// ── URL classification helpers ──────────────────────────────────────

/// URLs that require yt-dlp extraction (platforms that don't serve
/// raw audio at a direct URL). These MUST be downloaded first.
///
/// Matches the Python original's `EXTERNAL_URL_PATTERN`:
/// `youtube|youtu.be|soundcloud|bandcamp` (plus twitch).
fn needs_ytdlp(url: &str) -> bool {
    let lower = url.to_lowercase();
    lower.contains("youtube.com/")
        || lower.contains("youtu.be/")
        || lower.contains("twitch.tv/")
        || lower.contains("soundcloud.com/")
        || lower.contains("bandcamp.com/")
}

/// Heuristic: does this URL *look* like a live internet radio stream?
/// (Used for logging / display only — dispatch is controlled by `SourceKind`.)
fn is_live_stream_hint(url: &str) -> bool {
    let lower = url.to_lowercase();
    // Common Icecast/Shoutcast mount patterns
    lower.contains("/stream")
        || lower.contains("/live")
        || lower.contains("/radio")
        || lower.contains(";stream")
        || lower.contains("icecast")
        || lower.contains("shoutcast")
        || lower.ends_with(".m3u8")
        || lower.ends_with(".m3u")
        || lower.ends_with(".pls")
        || lower.contains(":8000/")   // common Icecast port
        || lower.contains(":8080/") // common alt port
}

async fn resolve_source(
    ctx: Context<'_>,
    melodia: Option<String>,
    file: Option<serenity::Attachment>,
) -> Result<ResolvedSource> {
    // ── File attachment ──────────────────────────────────────────
    // Discord attachment URLs are direct media file URLs — ffmpeg streams
    // them without a full download.
    if let Some(file) = file {
        return Ok(ResolvedSource {
            url: file.url.clone(),
            display_name: file.filename.clone(),
            kind: SourceKind::Stream,
        });
    }

    let name = melodia.ok_or_else(|| Error::Custom(lang::L_MUSIC_NEED_NAME.into()))?;

    // ── Autocomplete cache (per-user: (UserId, filename) → SearchHit) ─
    if let Some(hit) = ctx.data().ac_lookup(ctx.author().id, &name).await {
        let path = hit.url_path().unwrap_or("");
        let path = if path.starts_with('/') {
            path.to_string()
        } else {
            format!("/{path}")
        };
        let url = ctx.data().copyparty.build_url(&path);
        let display_name = clean_name(hit.filename().unwrap_or(&name));
        return Ok(ResolvedSource {
            url,
            display_name,
            kind: SourceKind::Stream,
        });
    }

    // ── Direct Copyparty path (starts with '/') ──────────────────
    if name.starts_with('/') {
        let url = ctx.data().copyparty.build_url(&name);
        let display_name = clean_name(name.rsplit('/').next().unwrap_or(&name));
        return Ok(ResolvedSource {
            url,
            display_name,
            kind: SourceKind::Stream,
        });
    }

    // ── Direct HTTP(S) URL ───────────────────────────────────────
    if name.starts_with("http://") || name.starts_with("https://") {
        let url = name.clone();
        let display_name = clean_name(url.rsplit('/').next().unwrap_or(&url));

        // yt-dlp platforms → download; everything else (radio, HLS,
        // playlists, Copyparty, direct media) → ffmpeg stream.
        let kind = if needs_ytdlp(&url) {
            SourceKind::YtDlp
        } else {
            SourceKind::Stream
        };
        return Ok(ResolvedSource {
            url,
            display_name,
            kind,
        });
    }

    // ── Fallback: search Copyparty ───────────────────────────────
    info!(query = %name, "searching copyparty for audio");
    let results = ctx
        .data()
        .copyparty
        .search(
            &name,
            5,
            &["mp3", "wav", "ogg", "flac", "m4a", "opus", "mp4"],
        )
        .await
        .map_err(|e| {
            error!(query = %name, error = %e, "copyparty search failed");
            Error::Custom(lang::fmt_music_search_failed(&e))
        })?;
    let hit = results
        .first()
        .ok_or_else(|| Error::Custom(lang::L_MUSIC_NO_AUDIO_ON_CP.into()))?;
    let path = hit
        .url_path()
        .ok_or_else(|| Error::Custom(lang::L_MUSIC_NO_URL_IN_RESULT.into()))?;
    let path = if path.starts_with('/') {
        path.to_string()
    } else {
        format!("/{path}")
    };
    let url = ctx.data().copyparty.build_url(&path);
    let display_name = clean_name(hit.filename().unwrap_or("unknown"));
    Ok(ResolvedSource {
        url,
        display_name,
        kind: SourceKind::Stream,
    })
}

/// Strip `?pw=...` / `&pw=...` query params from a URL for safe logging.
fn redact_url(url: &str) -> &str {
    let Some(q) = url.find('?') else {
        return url;
    };
    let before = &url[..q];
    let after = &url[q..];
    // Strip `?pw=...` or `&pw=...`
    if after.strip_prefix("?pw=").is_some() {
        return before;
    }
    if let Some(idx) = after.find("&pw=") {
        return &url[..q + idx];
    }
    url
}

/// Strip tracking/playlist params (`&...`) from YouTube URLs.
/// yt-dlp only needs `?v=ID`; extra `&` params can cause failures.
pub(crate) fn sanitize_yt_url(url: &str) -> String {
    let lower = url.to_lowercase();
    if (lower.contains("youtube.com/") || lower.contains("youtu.be/"))
        && let Some(pos) = url.find('&') {
            return url[..pos].to_string();
        }
    url.to_string()
}

// ── Playlist resolution is handled by ffmpeg natively ──────────────
// ffmpeg reads `.m3u`/`.m3u8`/`.pls` playlists directly (HLS segment
// fetching, PLS/M3U entry parsing) — no manual resolution needed.
// This mirrors the Python bot's `FFmpegPCMAudio(source, ...)` approach.

async fn play_impl(
    ctx: Context<'_>,
    melodia: Option<String>,
    file: Option<serenity::Attachment>,
    compressed: bool,
) -> Result<()> {
    ctx.defer().await?;

    let guild_id = ctx.guild_id().ok_or_else(lang::err_not_in_guild)?;

    let channel_id = ctx
        .serenity_context()
        .cache
        .guild(guild_id)
        .and_then(|g| {
            g.voice_states
                .get(&ctx.author().id)
                .and_then(|vs| vs.channel_id)
        })
        .ok_or_else(lang::err_not_in_voice)?;

    let src = resolve_source(ctx, melodia, file).await?;

    let call;
    let input;

    if compressed {
        // ── Compressed path: download → compress → decode ──────────
        // Defer stopping current track until compression is done.
        let audio_bytes = match src.kind {
            SourceKind::YtDlp => {
                let clean_url = sanitize_yt_url(&src.url);
                info!(url = %clean_url, "downloading via yt-dlp for compression");
                crate::voice::ytdlp_download(&clean_url).await?
            }
            SourceKind::Stream => {
                if is_live_stream_hint(&src.url) {
                    ctx.say(lang::L_MUSIC_CANT_COMPRESS_LIVE).await?;
                    // Fall through to normal streaming below
                    let live = true;
                    info!(url = %redact_url(&src.url), live, "live stream — compression skipped, streaming via ffmpeg");
                    // Stop current, connect, stream
                    {
                        let mut map = ctx.data().music_tracks.lock().await;
                        if let Some(handle) = map.remove(&guild_id.get()) {
                            let _ = handle.stop();
                        }
                    }
                    let (call_res, input_res) = tokio::join!(
                        ctx.data().voice_manager.connect(guild_id, channel_id),
                        crate::voice::ffmpeg_stream_input(&src.url)
                    );
                    call = call_res?;
                    input = input_res?;
                    // skip the rest of the compressed path
                    let handle = {
                        let mut call_lock = call.lock().await;
                        call_lock.play_input(input)
                    };
                    ctx.data()
                        .music_tracks
                        .lock()
                        .await
                        .insert(guild_id.get(), handle);
                    ctx.say(lang::fmt_music_playing(&src.display_name)).await?;
                    return Ok(());
                }
                info!(url = %redact_url(&src.url), "downloading for compression");
                crate::voice::download_url(&ctx.data().http_client, &src.url).await?
            }
        };

        info!("degrading audio ({} bytes)", audio_bytes.len());
        let degraded = crate::voice::degrade_audio(&audio_bytes).await?;

        // Deferred stop: only interrupt current track now that we're ready.
        {
            let mut map = ctx.data().music_tracks.lock().await;
            if let Some(handle) = map.remove(&guild_id.get()) {
                let _ = handle.stop();
            }
        }
        call = ctx
            .data()
            .voice_manager
            .connect(guild_id, channel_id)
            .await?;
        input = degraded;
    } else {
        // ── Normal path: stop first, then stream/download ──────────
        {
            let mut map = ctx.data().music_tracks.lock().await;
            if let Some(handle) = map.remove(&guild_id.get()) {
                let _ = handle.stop();
            }
        }

        match src.kind {
            SourceKind::YtDlp => {
                let clean_url = sanitize_yt_url(&src.url);
                info!(url = %clean_url, "downloading via yt-dlp");
                let audio_bytes = crate::voice::ytdlp_download(&clean_url).await?;
                let (call_res, input_res) = tokio::join!(
                    ctx.data().voice_manager.connect(guild_id, channel_id),
                    tokio::task::spawn_blocking(move || crate::voice::decode_audio(&audio_bytes))
                );
                call = call_res?;
                input = input_res??;
            }
            SourceKind::Stream => {
                let live = is_live_stream_hint(&src.url);
                info!(url = %redact_url(&src.url), live, "streaming via ffmpeg subprocess");
                let (call_res, input_res) = tokio::join!(
                    ctx.data().voice_manager.connect(guild_id, channel_id),
                    crate::voice::ffmpeg_stream_input(&src.url)
                );
                call = call_res?;
                input = input_res?;
            }
        }
    }

    let handle = {
        let mut call_lock = call.lock().await;
        call_lock.play_input(input)
    };

    ctx.data()
        .music_tracks
        .lock()
        .await
        .insert(guild_id.get(), handle);

    ctx.say(lang::fmt_music_playing(&src.display_name)).await?;
    Ok(())
}

/// Stop playback and disconnect from voice
#[poise::command(slash_command)]
pub async fn stop(ctx: Context<'_>) -> Result<()> {
    let guild_id = ctx.guild_id().ok_or_else(lang::err_not_in_guild)?;
    ctx.data().voice_manager.disconnect(guild_id).await?;
    ctx.data().music_tracks.lock().await.remove(&guild_id.get());
    ctx.send(
        poise::CreateReply::default()
            .content(lang::L_MUSIC_STOPPED)
            .ephemeral(true),
    )
    .await?;
    Ok(())
}

/// Join your voice channel
#[poise::command(slash_command)]
pub async fn join(ctx: Context<'_>) -> Result<()> {
    ctx.defer().await?;
    let guild_id = ctx.guild_id().ok_or_else(lang::err_not_in_guild)?;

    let channel_id = ctx.serenity_context().cache.guild(guild_id).and_then(|g| {
        g.voice_states
            .get(&ctx.author().id)
            .and_then(|vs| vs.channel_id)
    });

    match channel_id {
        Some(cid) => match ctx.data().voice_manager.connect(guild_id, cid).await {
            Ok(_) => {
                ctx.say(lang::fmt_voice_joined(&cid)).await?;
            }
            Err(e) => {
                ctx.say(lang::fmt_voice_join_failed(&e)).await?;
            }
        },
        None => {
            ctx.say(lang::L_VOICE_USER_NOT_IN_VC).await?;
        }
    }
    Ok(())
}

pub fn commands() -> Vec<poise::Command<Data, Error>> {
    vec![grajcuj(), stop(), join()]
}