use std::time::Duration;

use poise::serenity_prelude as serenity;
use tracing::warn;

use super::autocomplete::any_file;
use crate::music::sanitize_yt_url;
use crate::Data;
use crate::copyparty::{html_decode, percent_decode, redact_url};
use crate::error::{Error, Result};
use crate::lang;

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

// Above this size (or when `serwer` is forced) the result is uploaded to
// copyparty instead of being attached to the Discord reply. Discord's own
// attachment limit is 25 MiB for non-Nitro, but 10 MiB matches the Python
// original and keeps replies snappy.
const LARGE_FILE_THRESHOLD: usize = 10 * 1024 * 1024;

/// Hard cap for a single `/download` result (before it is read into memory).
const MAX_DOWNLOAD_BYTES: u64 = 512 * 1024 * 1024;

#[derive(Clone, Copy, PartialEq, Eq)]
pub(crate) enum FileType {
    Video,
    Audio,
    Image,
    Unknown,
}

/// Classify a file by its extension.
///
/// Mirrors Python's `mimetypes.guess_type`-based `filetype()` helper without
/// pulling in a mime crate: the set of extensions below covers everything the
/// original bot handled.
pub(crate) fn file_type(filename: &str) -> FileType {
    let Some((_, ext)) = filename.rsplit_once('.') else {
        return FileType::Unknown;
    };
    if ext.is_empty() || ext.contains('/') {
        return FileType::Unknown;
    }
    match ext.to_ascii_lowercase().as_str() {
        "mp4" | "avi" | "mkv" | "mov" | "webm" | "flv" | "wmv" | "m4v" | "mpg" | "mpeg" | "3gp"
        | "ts" => FileType::Video,
        "mp3" | "wav" | "ogg" | "flac" | "m4a" | "opus" | "aac" | "wma" | "oga" => FileType::Audio,
        "jpg" | "jpeg" | "png" | "gif" | "bmp" | "webp" | "tiff" | "tif" | "avif" => {
            FileType::Image
        }
        _ => FileType::Unknown,
    }
}

/// Lowercased extension without the leading dot, or `None` if there is none.
fn ext_of(filename: &str) -> Option<String> {
    let (_, ext) = filename.rsplit_once('.')?;
    if ext.is_empty() || ext.contains('/') {
        None
    } else {
        Some(ext.to_ascii_lowercase())
    }
}

/// Filename stem: everything before the final dot of the basename.
pub(crate) fn stem_of(filename: &str) -> &str {
    let base = filename.rsplit('/').next().unwrap_or(filename);
    match base.rsplit_once('.') {
        Some((stem, _)) if !stem.is_empty() => stem,
        _ => base,
    }
}

/// A safe basename: no directory components, no characters Discord/Copyparty
/// filenames commonly abuse, and never `.`/`..`.
fn safe_basename(name: &str) -> String {
    // Treat both separators as directory boundaries: Discord filenames may
    // come from Windows clients even though the bot runs on Linux.
    let base = name.rsplit(['/', '\\']).next().unwrap_or(name);
    let cleaned = sanitize_filename(base)
        .trim_matches(|c| c == '.' || c == ' ')
        .to_string();
    if cleaned.is_empty() {
        "file".to_string()
    } else {
        cleaned
    }
}

/// Create a unique per-operation directory and return
/// `(directory, input_path, output_path)`. Concurrent commands can never
/// overwrite or delete each other's files.
async fn temp_op(
    original: &str,
    output_name: &str,
) -> std::io::Result<(String, String, String)> {
    let safe = safe_basename(original);
    let ext = ext_of(&safe)
        .map(|ext| format!(".{ext}"))
        .unwrap_or_default();
    let dir = format!(
        "{}/op_{}",
        crate::config::temp_path(),
        uuid::Uuid::new_v4()
    );
    tokio::fs::create_dir_all(&dir).await?;
    let input_path = format!("{dir}/input{ext}");
    let output_path = format!("{dir}/{}", safe_basename(output_name));
    Ok((dir, input_path, output_path))
}

/// Best-effort removal of a per-operation temp directory.
async fn cleanup_dir(dir: &str) {
    let _ = tokio::fs::remove_dir_all(dir).await;
}

/// Resolve the input source — either an autocomplete-picked copyparty file or
/// a Discord attachment — downloading the bytes and returning them alongside
/// the original filename.
///
/// Replies with an appropriate user-facing message and returns `Ok(None)` when
/// no valid source was supplied, so callers can early-return without sending a
/// second message.
async fn resolve_input(
    ctx: &Context<'_>,
    plik: Option<&str>,
    zalacznik: Option<&serenity::Attachment>,
) -> Result<Option<(Vec<u8>, String)>> {
    if let Some(name) = plik {
        // Autocomplete-selected copyparty file: the choice value is the decoded
        // filename, stashed into the per-user ac_cache by `any_file`.
        let hit = match ctx.data().ac_lookup(ctx.author().id, name).await {
            Some(h) => h,
            None => {
                ctx.say(lang::L_UTIL_PICK_FROM_AUTOCOMPLETE).await?;
                return Ok(None);
            }
        };
        let path = hit.url_path().unwrap_or("");
        let path = if path.starts_with('/') {
            path.to_string()
        } else {
            format!("/{path}")
        };
        let full_url = ctx.data().copyparty.build_url(&path);
        let resp = ctx.data().http_client.get(&full_url).send().await?;
        if !resp.status().is_success() {
            ctx.say(lang::L_UTIL_DOWNLOAD_FAILED).await?;
            return Ok(None);
        }
        let bytes = resp.bytes().await?.to_vec();
        return Ok(Some((bytes, name.to_string())));
    }

    if let Some(att) = zalacznik {
        let resp = ctx.data().http_client.get(&att.url).send().await?;
        if !resp.status().is_success() {
            ctx.say(lang::L_UTIL_DOWNLOAD_FAILED).await?;
            return Ok(None);
        }
        let bytes = resp.bytes().await?.to_vec();
        return Ok(Some((bytes, att.filename.clone())));
    }

    ctx.say(lang::L_UTIL_NEED_INPUT).await?;
    Ok(None)
}

/// Output extension the compressor produces for a given input.
///
/// - Video keeps its container extension (ffmpeg re-muxes in place).
/// - Audio is always re-encoded to Opus in an `.ogg` container.
/// - JPEG/GIF keep their extension; other images are rewritten to `.jpg`.
pub(crate) fn compress_output_ext(ft: FileType, original: &str) -> String {
    let orig = ext_of(original);
    match ft {
        FileType::Video => orig.unwrap_or_else(|| "mp4".to_string()),
        FileType::Audio => "ogg".to_string(),
        FileType::Image => match orig.as_deref() {
            Some("jpg" | "jpeg" | "gif") => orig.unwrap(),
            _ => "jpg".to_string(),
        },
        FileType::Unknown => String::new(),
    }
}

/// Build the ffmpeg/magick command for extreme-low-quality compression.
/// Returns `None` for unsupported (`Unknown`) file types.
pub(crate) fn build_compress_command(
    ft: FileType,
    input: &str,
    output: &str,
) -> Option<tokio::process::Command> {
    match ft {
        FileType::Video => {
            let mut c = tokio::process::Command::new("ffmpeg");
            c.arg("-y")
                .arg("-i")
                .arg(input)
                .arg("-c:v")
                .arg("libx264")
                .arg("-crf")
                .arg("51")
                .arg("-b:v")
                .arg("100")
                .arg("-vf")
                .arg("fps=10,scale=trunc(iw*0.5/2)*2:trunc(ih*0.5/2)*2")
                .arg("-preset")
                .arg("ultrafast")
                .arg("-c:a")
                .arg("libopus")
                .arg("-b:a")
                .arg("500")
                .arg(output);
            Some(c)
        }
        FileType::Audio => {
            let mut c = tokio::process::Command::new("ffmpeg");
            c.arg("-y")
                .arg("-i")
                .arg(input)
                .arg("-c:a")
                .arg("libopus")
                .arg("-b:a")
                .arg("500")
                .arg("-ar")
                .arg("12000")
                .arg("-ac")
                .arg("1")
                .arg(output);
            Some(c)
        }
        FileType::Image => {
            let mut c = tokio::process::Command::new("magick");
            c.arg(input);
            match ext_of(input).as_deref() {
                Some("gif") => {
                    c.arg("-coalesce")
                        .arg("-resize")
                        .arg("30%")
                        .arg("-colors")
                        .arg("32")
                        .arg("-strip")
                        .arg("-layers")
                        .arg("Optimize");
                }
                // jpg/jpeg stay jpg; other images are rewritten to .jpg by
                // `compress_output_ext` and magick infers the encoder from the
                // output extension.
                _ => {
                    c.arg("-strip")
                        .arg("-resize")
                        .arg("30%")
                        .arg("-quality")
                        .arg("5");
                }
            }
            c.arg(output);
            Some(c)
        }
        FileType::Unknown => None,
    }
}

enum DeliverKind {
    Compress,
    Convert,
}

/// Compress a single in-memory blob (an attachment body) into a compressed
/// file, returning the encoded bytes and the output filename.
///
/// Mirrors the per-attachment path of Python's `Compression` message command,
/// but each invocation gets its own temp directory, so concurrent calls cannot
/// overwrite or delete each other's files.
async fn compress_attachment_bytes(
    ft: FileType,
    original: &str,
    input_bytes: &[u8],
) -> Option<(Vec<u8>, String)> {
    let safe_original = safe_basename(original);
    let stem = stem_of(&safe_original).to_string();
    let out_ext = compress_output_ext(ft, &safe_original);
    let out_filename = format!("compressed_{stem}.{out_ext}");
    let (dir, input_path, output_path) = temp_op(&safe_original, &out_filename).await.ok()?;

    if tokio::fs::write(&input_path, input_bytes).await.is_err() {
        cleanup_dir(&dir).await;
        return None;
    }
    let Some(mut cmd) = build_compress_command(ft, &input_path, &output_path) else {
        cleanup_dir(&dir).await;
        return None;
    };
    let res = match cmd.output().await {
        Ok(out) if out.status.success() => tokio::fs::read(&output_path).await.ok(),
        _ => None,
    };
    cleanup_dir(&dir).await;
    res.map(|b| (b, out_filename))
}

/// Compress audio bytes for playback using Vorbis (symphonia-decodable).
/// Uses Vorbis instead of Opus because symphonia 0.6 lacks an Opus decoder.
/// Returns the compressed .ogg bytes on success.
pub(crate) async fn compress_audio_bytes(input_bytes: &[u8], original_name: &str) -> Option<Vec<u8>> {
    let safe_name = safe_basename(original_name);
    let stem = stem_of(&safe_name).to_string();
    let out_filename = format!("compressed_{stem}.ogg");
    let (dir, input_path, output_path) = temp_op(&safe_name, &out_filename).await.ok()?;

    if let Err(e) = tokio::fs::write(&input_path, input_bytes).await {
        tracing::warn!("compress_audio_bytes: failed to write input: {e}");
        cleanup_dir(&dir).await;
        return None;
    }
    tracing::debug!(
        input = %input_path,
        output = %output_path,
        bytes = input_bytes.len(),
        "compress_audio_bytes: running ffmpeg"
    );

    // Opus at 500bps, 12 kHz, mono — same as /compress.
    // Decoded via ffmpeg in the caller (symphonia lacks Opus support).
    let mut cmd = tokio::process::Command::new("ffmpeg");
    cmd.arg("-y")
        .arg("-i")
        .arg(&input_path)
        .arg("-c:a")
        .arg("libopus")
        .arg("-b:a")
        .arg("500")
        .arg("-ar")
        .arg("12000")
        .arg("-ac")
        .arg("1")
        .arg(&output_path);

    let res = match cmd.output().await {
        Ok(out) if out.status.success() => tokio::fs::read(&output_path).await.ok(),
        Ok(out) => {
            let stderr = String::from_utf8_lossy(&out.stderr);
            tracing::warn!(
                input = %input_path,
                output = %output_path,
                exit = %out.status,
                "compress_audio_bytes ffmpeg failed:\n{}",
                stderr.chars().take(500).collect::<String>()
            );
            None
        }
        Err(e) => {
            tracing::warn!("compress_audio_bytes ffmpeg spawn error: {e}");
            None
        }
    };
    cleanup_dir(&dir).await;
    res
}

/// Strip characters that Discord/coping filenames can't safely carry. Mirrors
/// Python's `Downloader._sanitize_filename`.
fn sanitize_filename(name: &str) -> String {
    const BAD: &[char] = &['<', '>', ':', '"', '/', '\\', '|', '?', '*'];
    name.chars()
        .filter(|c| !BAD.contains(c))
        .collect::<String>()
        .trim()
        .to_string()
}

/// Extract `http://` and `https://` URLs from text. After consuming each URL,
/// trailing characters not in the RFC 3986 unreserved + sub-delims set are
/// stripped (e.g. a trailing backtick that should have been URL-encoded).
pub(crate) fn extract_urls(content: &str) -> Vec<String> {
    fn is_url_char(b: u8) -> bool {
        b.is_ascii_alphanumeric()
            || matches!(
                b,
                b'-' | b'.' | b'_' | b'~' | b':' | b'/' | b'?' | b'#' | b'[' | b']' | b'@'
                    | b'!' | b'$' | b'&' | b'\'' | b'(' | b')' | b'*' | b'+' | b',' | b';'
                    | b'%' | b'='
            )
    }
    let bytes = content.as_bytes();
    let mut urls = Vec::new();
    let mut i = 0;
    while i < bytes.len() {
        // Find next http:// or https://
        let scheme = if bytes[i..].starts_with(b"https://") {
            Some("https://")
        } else if bytes[i..].starts_with(b"http://") {
            Some("http://")
        } else {
            None
        };
        let Some(s) = scheme else {
            i += 1;
            continue;
        };
        let start = i;
        let after = i + s.len();

        // Consume the host (until `/` or whitespace).
        let mut j = after;
        while j < bytes.len() && !bytes[j].is_ascii_whitespace() && bytes[j] != b'/' {
            j += 1;
        }

        if j < bytes.len() && bytes[j] == b'/' {
            // Consume the rest of the URL (valid URL chars only).
            let mut k = j;
            while k < bytes.len() && is_url_char(bytes[k]) {
                k += 1;
            }
            if k > after {
                urls.push(content[start..k].to_string());
            }
            i = k;
        } else {
            // No path component — not matched; advance past it.
            i = after;
        }
    }
    urls
}

/// Locate the single file yt-dlp produced in `dir`, picking the most recently
/// modified one (matches Python's `os.listdir`-first fallback behaviour while
/// being deterministic enough for the per-call unique subdir).
async fn find_downloaded_file(dir: &str) -> Option<(String, String)> {
    let mut rd = tokio::fs::read_dir(dir).await.ok()?;
    let mut newest: Option<(std::time::SystemTime, String)> = None;
    while let Ok(Some(entry)) = rd.next_entry().await {
        let meta = match entry.metadata().await {
            Ok(m) => m,
            Err(_) => continue,
        };
        if !meta.is_file() {
            continue;
        }
        let mtime = match meta.modified() {
            Ok(t) => t,
            Err(_) => continue,
        };
        if let Some((t, _)) = &newest
            && *t >= mtime {
                continue;
            }
        newest = Some((mtime, entry.path().to_string_lossy().into_owned()));
    }
    newest.map(|(_, p)| {
        let fname = std::path::Path::new(&p)
            .file_name()
            .map(|s| s.to_string_lossy().into_owned())
            .unwrap_or_default();
        (p, fname)
    })
}

/// Hand the produced download back to the user: attach when below the size
/// threshold (and upload isn't forced), otherwise push to copyparty and reply
/// with the download URL. Mirrors Python's `Downloader` slash `/download`.
async fn deliver_download(
    ctx: &Context<'_>,
    bytes: Vec<u8>,
    filename: String,
    catbox: bool,
) -> Result<()> {
    if bytes.len() > LARGE_FILE_THRESHOLD || catbox {
        match ctx.data().copyparty.upload(&filename, bytes).await {
            Ok(url) => {
                ctx.say(lang::fmt_download_uploaded(&url)).await?;
            }
            Err(e) => {
                tracing::warn!("copyparty upload failed: {e}");
                ctx.say(lang::L_UTIL_UPLOAD_FAILED).await?;
            }
        }
    } else {
        ctx.send(
            poise::CreateReply::default()
                .attachment(serenity::CreateAttachment::bytes(bytes, filename)),
        )
        .await?;
    }
    Ok(())
}

/// Run yt-dlp on `url` and deliver the resulting file. The caller is expected
/// to have already called `ctx.defer()`. Each invocation uses a fresh unique
/// subdirectory under `TEMP_PATH` (matching Python's per-call
/// `tempfile.TemporaryDirectory`) so concurrent downloads never collide.
async fn run_download(
    ctx: &Context<'_>,
    url: &str,
    catbox: bool,
    fformat: Option<&str>,
    filename_user: Option<&str>,
) -> Result<()> {
    // Copyparty may legitimately live on localhost/LAN; every other host must
    // be public. This blocks metadata endpoints and internal services.
    if !ctx.data().copyparty.is_own_url(url) {
        crate::net::ensure_public_http_url(url).await?;
    }
    let fmt = fformat.unwrap_or("mp4");
    let is_audio = matches!(fmt, "mp3" | "wav" | "m4a");
    let dl_dir = format!("{}/dl_{}", crate::config::temp_path(), uuid::Uuid::new_v4());
    tokio::fs::create_dir_all(&dl_dir).await.ok();

    let out_template = match filename_user {
        Some(name) => {
            // Custom filename: sanitize, cap at 100 chars, let yt-dlp append ext.
            let clean: String = sanitize_filename(name).chars().take(100).collect();
            format!("{dl_dir}/{clean}.%(ext)s")
        }
        None => format!("{dl_dir}/%(title).100s.%(ext)s"),
    };

    let mut cmd = tokio::process::Command::new("yt-dlp");
    // `--ignore-config` keeps a planted config file from injecting options;
    // `--` stops a user-supplied URL from being parsed as a flag.
    cmd.arg("--ignore-config")
        .arg("--no-playlist")
        .arg("-f")
        .arg("bestaudio/bestvideo+bestaudio")
        .arg("--merge-output-format")
        .arg("mp4")
        .arg("--max-filesize")
        .arg("512M")
        .arg("-o")
        .arg(&out_template);
    if is_audio {
        cmd.arg("--extract-audio").arg("--audio-format").arg(fmt);
    }
    cmd.arg("--").arg(sanitize_yt_url(url));

    let output = match tokio::time::timeout(Duration::from_secs(600), cmd.output()).await {
        Ok(result) => result.map_err(|e| Error::Custom(lang::fmt_ytdlp_err(&e)))?,
        Err(_) => {
            let _ = tokio::fs::remove_dir_all(&dl_dir).await;
            ctx.say(lang::fmt_download_failed("download timed out after 10 minutes"))
                .await?;
            return Ok(());
        }
    };
    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        // Keep the full yt-dlp trace in the logs; the user only sees the
        // short `fmt_download_failed` (translated) message.
        warn!(
            url = %redact_url(url),
            "yt-dlp failed:\n{}",
            stderr.trim_end()
        );
        let _ = tokio::fs::remove_dir_all(&dl_dir).await;
        ctx.say(lang::fmt_download_failed(&stderr)).await?;
        return Ok(());
    }

    let Some((actual_path, basename)) = find_downloaded_file(&dl_dir).await else {
        let _ = tokio::fs::remove_dir_all(&dl_dir).await;
        ctx.say(lang::fmt_download_failed("no file produced"))
            .await?;
        return Ok(());
    };

    // Determine the display filename for the upload/attachment.
    let final_name = match filename_user {
        Some(name) => {
            let clean: String = sanitize_filename(name).chars().take(100).collect();
            let ext = std::path::Path::new(&basename)
                .extension()
                .map(|e| format!(".{}", e.to_string_lossy()))
                .unwrap_or_default();
            format!("{clean}{ext}")
        }
        None => basename,
    };

    match tokio::fs::metadata(&actual_path).await {
        Ok(meta) if meta.len() > MAX_DOWNLOAD_BYTES => {
            let _ = tokio::fs::remove_dir_all(&dl_dir).await;
            ctx.say(lang::fmt_download_failed("file is larger than 512 MiB"))
                .await?;
            return Ok(());
        }
        _ => {}
    }

    let bytes = match tokio::fs::read(&actual_path).await {
        Ok(b) => b,
        Err(e) => {
            let _ = tokio::fs::remove_dir_all(&dl_dir).await;
            ctx.say(lang::fmt_download_failed(&e.to_string())).await?;
            return Ok(());
        }
    };

    let deliver_result = deliver_download(ctx, bytes, final_name, catbox).await;
    let _ = tokio::fs::remove_dir_all(&dl_dir).await;
    deliver_result
}

/// Hand the produced bytes back to the user.
///
/// Below the size threshold (and when upload isn't forced) the result is
/// attached directly to the reply. Otherwise it's pushed to copyparty and the
/// reply contains the download URL. Upload failures are reported gracefully
/// rather than propagated, matching the Python original.
async fn deliver(
    ctx: &Context<'_>,
    bytes: Vec<u8>,
    filename: String,
    force_upload: bool,
    kind: DeliverKind,
) -> Result<()> {
    if bytes.len() > LARGE_FILE_THRESHOLD || force_upload {
        match ctx.data().copyparty.upload(&filename, bytes).await {
            Ok(url) => {
                let msg = match kind {
                    DeliverKind::Compress => lang::fmt_util_compressed(&url),
                    DeliverKind::Convert => lang::fmt_util_converted(&url),
                };
                ctx.say(msg).await?;
            }
            Err(e) => {
                tracing::warn!("copyparty upload failed: {e}");
                ctx.say(lang::L_UTIL_UPLOAD_FAILED).await?;
            }
        }
    } else {
        ctx.send(
            poise::CreateReply::default()
                .attachment(serenity::CreateAttachment::bytes(bytes, filename)),
        )
        .await?;
    }
    Ok(())
}

/// Compress media to extreme low quality
#[poise::command(slash_command, aliases("kompresja"))]
pub async fn compress(
    ctx: Context<'_>,
    #[description = "File from Copyparty"]
    #[autocomplete = "any_file"]
    plik: Option<String>,
    #[description = "File from Discord"] zalacznik: Option<serenity::Attachment>,
    #[description = "Force upload to Copyparty"] serwer: Option<bool>,
) -> Result<()> {
    ctx.defer().await?;
    tokio::fs::create_dir_all(crate::config::temp_path())
        .await
        .ok();

    let (input_bytes, original_filename) =
        match resolve_input(&ctx, plik.as_deref(), zalacznik.as_ref()).await? {
            Some(v) => v,
            None => return Ok(()),
        };

    let safe_original = safe_basename(&original_filename);
    let ft = file_type(&safe_original);
    let stem = stem_of(&safe_original).to_string();
    let out_ext = compress_output_ext(ft, &safe_original);
    let out_filename = format!("compressed_{stem}.{out_ext}");
    let Some((dir, input_path, output_path)) = temp_op(&safe_original, &out_filename).await.ok()
    else {
        ctx.say(lang::L_UTIL_COMPRESS_FAILED).await?;
        return Ok(());
    };

    if let Err(e) = tokio::fs::write(&input_path, &input_bytes).await {
        tracing::warn!("compress: failed to write input: {e}");
        cleanup_dir(&dir).await;
        ctx.say(lang::L_UTIL_COMPRESS_FAILED).await?;
        return Ok(());
    }

    let result = match build_compress_command(ft, &input_path, &output_path) {
        Some(mut cmd) => cmd.output().await,
        None => {
            cleanup_dir(&dir).await;
            ctx.say(lang::L_UTIL_UNSUPPORTED_TYPE).await?;
            return Ok(());
        }
    };

    match result {
        Ok(out) if out.status.success() => match tokio::fs::read(&output_path).await {
            Ok(out_bytes) => {
                cleanup_dir(&dir).await;
                deliver(
                    &ctx,
                    out_bytes,
                    out_filename,
                    serwer.unwrap_or(false),
                    DeliverKind::Compress,
                )
                .await?;
            }
            Err(e) => {
                tracing::warn!("compress: output missing after encode: {e}");
                cleanup_dir(&dir).await;
                ctx.say(lang::L_UTIL_COMPRESS_FAILED).await?;
            }
        },
        _ => {
            cleanup_dir(&dir).await;
            ctx.say(lang::L_UTIL_COMPRESS_FAILED).await?;
        }
    }
    Ok(())
}

/// Convert media between formats
#[poise::command(slash_command, aliases("konwersja"))]
pub async fn convert(
    ctx: Context<'_>,
    #[description = "File from Copyparty"]
    #[autocomplete = "any_file"]
    plik: Option<String>,
    #[description = "File from Discord"] zalacznik: Option<serenity::Attachment>,
    #[description = "Target format extension (e.g. mp3, wav, avi, png)"] format: String,
    #[description = "Force upload to Copyparty"] serwer: Option<bool>,
) -> Result<()> {
    ctx.defer().await?;
    tokio::fs::create_dir_all(crate::config::temp_path())
        .await
        .ok();

    let (input_bytes, original_filename) =
        match resolve_input(&ctx, plik.as_deref(), zalacznik.as_ref()).await? {
            Some(v) => v,
            None => return Ok(()),
        };

    // Normalise the requested extension: lowercase, no leading dot, and reject
    // anything containing path separators or extra dots — this keeps it a
    // single clean extension component and rules out escaping TEMP_PATH.
    let fmt = format.trim().trim_start_matches('.').to_ascii_lowercase();
    if fmt.is_empty() || fmt.contains('/') || fmt.contains('\\') || fmt.contains('.') {
        ctx.say(lang::L_UTIL_UNSUPPORTED_TYPE).await?;
        return Ok(());
    }

    let safe_original = safe_basename(&original_filename);
    let ft = file_type(&safe_original);
    let stem = stem_of(&safe_original).to_string();
    let out_filename = format!("{stem}.{fmt}");
    let Some((dir, input_path, output_path)) = temp_op(&safe_original, &out_filename).await.ok()
    else {
        ctx.say(lang::L_UTIL_CONVERT_FAILED).await?;
        return Ok(());
    };

    if let Err(e) = tokio::fs::write(&input_path, &input_bytes).await {
        tracing::warn!("convert: failed to write input: {e}");
        cleanup_dir(&dir).await;
        ctx.say(lang::L_UTIL_CONVERT_FAILED).await?;
        return Ok(());
    }

    let mut cmd = match ft {
        FileType::Video | FileType::Audio => {
            let mut c = tokio::process::Command::new("ffmpeg");
            c.arg("-y").arg("-i").arg(&input_path).arg(&output_path);
            c
        }
        FileType::Image => {
            let mut c = tokio::process::Command::new("magick");
            c.arg(&input_path).arg(&output_path);
            c
        }
        FileType::Unknown => {
            cleanup_dir(&dir).await;
            ctx.say(lang::L_UTIL_UNSUPPORTED_TYPE).await?;
            return Ok(());
        }
    };

    match cmd.output().await {
        Ok(out) if out.status.success() => match tokio::fs::read(&output_path).await {
            Ok(out_bytes) => {
                cleanup_dir(&dir).await;
                deliver(
                    &ctx,
                    out_bytes,
                    out_filename,
                    serwer.unwrap_or(false),
                    DeliverKind::Convert,
                )
                .await?;
            }
            Err(e) => {
                tracing::warn!("convert: output missing after encode: {e}");
                cleanup_dir(&dir).await;
                ctx.say(lang::L_UTIL_CONVERT_FAILED).await?;
            }
        },
        Ok(out) => {
            let stderr = String::from_utf8_lossy(&out.stderr);
            cleanup_dir(&dir).await;
            ctx.say(lang::fmt_util_convert_err(&stderr)).await?;
        }
        Err(e) => {
            cleanup_dir(&dir).await;
            ctx.say(lang::fmt_util_convert_err(&e.to_string())).await?;
        }
    }
    Ok(())
}

/// Upload files from Discord to Copyparty
#[poise::command(slash_command)]
pub async fn upload(
    ctx: Context<'_>,
    #[description = "File to upload"] zalacznik: serenity::Attachment,
) -> Result<()> {
    ctx.defer().await?;

    let data = ctx
        .data()
        .http_client
        .get(&zalacznik.url)
        .send()
        .await?
        .bytes()
        .await?;
    let file_url = ctx
        .data()
        .copyparty
        .upload(&zalacznik.filename, data.to_vec())
        .await?;
    ctx.say(lang::fmt_uploaded(&file_url)).await?;
    Ok(())
}

/// Search Copyparty file server and return a direct URL
#[poise::command(slash_command)]
pub async fn search(
    ctx: Context<'_>,
    #[description = "Partial filename to search"]
    #[autocomplete = "any_file"]
    filename: String,
) -> Result<()> {
    // Autocomplete cache: per-user (UserId, filename) → SearchHit.
    if let Some(hit) = ctx.data().ac_lookup(ctx.author().id, &filename).await {
        let name = html_decode(&percent_decode(hit.filename().unwrap_or(&filename)));
        let path = hit.url_path().unwrap_or("");
        let path = if path.starts_with('/') {
            path.to_string()
        } else {
            format!("/{path}")
        };
        let full_url = format!("{}{}", ctx.data().config.copyparty_url, path);
        ctx.say(lang::fmt_search_result(&name, &full_url)).await?;
        return Ok(());
    }

    // Direct copyparty path from manual input (starts with /)
    if filename.starts_with('/') {
        let full_url = format!("{}{}", ctx.data().config.copyparty_url, filename);
        ctx.say(lang::fmt_search_result(&filename, &full_url))
            .await?;
        return Ok(());
    }

    let results = ctx.data().copyparty.search(&filename, 10, &[]).await?;

    if results.is_empty() {
        ctx.say(lang::L_SEARCH_NO_RESULTS).await?;
        return Ok(());
    }

    let hit = &results[0];
    let name = html_decode(&percent_decode(hit.filename().unwrap_or("unknown")));
    let path = hit.url_path().unwrap_or("");
    let path = if path.starts_with('/') {
        path.to_string()
    } else {
        format!("/{path}")
    };
    let full_url = format!("{}{}", ctx.data().config.copyparty_url, path);

    ctx.say(lang::fmt_search_result(&name, &full_url)).await?;
    Ok(())
}

/// Download media from any yt-dlp-supported URL
#[poise::command(slash_command)]
pub async fn download(
    ctx: Context<'_>,
    #[description = "Media URL"] url: String,
    #[description = "Force upload to Copyparty"] catbox: Option<bool>,
    #[description = "Output format (mp4, mp3, wav, etc.)"] fformat: Option<String>,
    #[description = "Custom output filename"] filename_user: Option<String>,
) -> Result<()> {
    ctx.defer().await?;
    tokio::fs::create_dir_all(crate::config::temp_path())
        .await
        .ok();
    run_download(
        &ctx,
        &url,
        catbox.unwrap_or(false),
        fformat.as_deref(),
        filename_user.as_deref(),
    )
    .await
}

/// Right-click a message → upload its attachments to Copyparty
/// (mirrors Python's `@commands.message_command(name="upload")`).
///
/// Display name is not `"upload"` because poise's dispatcher matches commands
/// by name alone without considering `CommandType`, so a context-menu named
/// `"upload"` would shadow — and be shadowed by — the slash `/upload` command
/// (see `poise::dispatch::find_matching_command`). `"Wypchnij załączniki"`
/// avoids the collision while keeping the Polish user-facing label.
#[poise::command(context_menu_command = "Wyślij załączniki")]
pub async fn message_upload(ctx: Context<'_>, message: serenity::Message) -> Result<()> {
    if message.attachments.is_empty() {
        ctx.say(lang::L_UTIL_NO_ATTACHMENTS).await?;
        return Ok(());
    }
    ctx.defer().await?;

    let mut urls: Vec<String> = Vec::new();
    let mut failed = 0usize;
    for att in &message.attachments {
        let resp = match ctx.data().http_client.get(&att.url).send().await {
            Ok(r) if r.status().is_success() => r,
            _ => {
                failed += 1;
                continue;
            }
        };
        let bytes = resp.bytes().await?.to_vec();
        match ctx.data().copyparty.upload(&att.filename, bytes).await {
            Ok(url) => urls.push(url),
            Err(e) => {
                tracing::warn!("upload: copyparty failed for {}: {e}", att.filename);
                failed += 1;
            }
        }
    }

    if urls.is_empty() {
        ctx.say(lang::L_UTIL_UPLOAD_FAILED).await?;
        return Ok(());
    }

    let mut resp = lang::fmt_upload_summary(urls.len());
    for u in &urls {
        resp.push_str(u);
        resp.push('\n');
    }
    if failed > 0 {
        resp.push_str(&lang::fmt_upload_partial_failed(failed));
    }
    ctx.say(resp).await?;
    Ok(())
}

/// Right-click a message → compress all of its attachments
/// (mirrors Python's `@commands.message_command(name="kompresja")`).
#[poise::command(context_menu_command = "kompresja")]
pub async fn message_compression(ctx: Context<'_>, message: serenity::Message) -> Result<()> {
    if message.attachments.is_empty() {
        ctx.say(lang::L_UTIL_NO_ATTACHMENTS).await?;
        return Ok(());
    }
    ctx.defer().await?;
    tokio::fs::create_dir_all(crate::config::temp_path())
        .await
        .ok();

    let total = message.attachments.len();
    let mut attachments_out: Vec<serenity::CreateAttachment> = Vec::new();
    let mut made = 0usize;

    for att in &message.attachments {
        let resp = match ctx.data().http_client.get(&att.url).send().await {
            Ok(r) if r.status().is_success() => r,
            _ => continue,
        };
        let bytes = match resp.bytes().await {
            Ok(b) => b.to_vec(),
            Err(_) => continue,
        };
        let ft = file_type(&att.filename);
        if let Some((out_bytes, out_name)) =
            compress_attachment_bytes(ft, &att.filename, &bytes).await
        {
            attachments_out.push(serenity::CreateAttachment::bytes(out_bytes, out_name));
            made += 1;
        }
    }

    if attachments_out.is_empty() {
        ctx.say(lang::L_UTIL_COMPRESS_FAILED).await?;
        return Ok(());
    }

    let mut reply =
        poise::CreateReply::default().content(lang::fmt_message_compressed(made, total));
    for a in attachments_out {
        reply = reply.attachment(a);
    }
    ctx.send(reply).await?;
    Ok(())
}

/// Right-click a message → download every `https://` URL it contains
/// (mirrors Python's `@commands.message_command(name="download")`).
///
/// Named `"Pobierz z linku"` rather than `"download"` to avoid colliding with
/// the slash `/download` command in poise's name-only dispatcher (see the note
/// on `message_upload`).
#[poise::command(context_menu_command = "Pobierz z linku")]
pub async fn message_download(ctx: Context<'_>, message: serenity::Message) -> Result<()> {
    let urls = extract_urls(&message.content);
    if urls.is_empty() {
        // Faithful to the Python original, which reuses the attachments-missing
        // string for the no-URL case.
        ctx.say(lang::L_UTIL_NO_ATTACHMENTS).await?;
        return Ok(());
    }
    ctx.defer().await?;
    tokio::fs::create_dir_all(crate::config::temp_path())
        .await
        .ok();

    for url in urls {
        if let Err(e) = run_download(&ctx, &url, false, Some("mp4"), None).await {
            tracing::warn!("download runner error for {url}: {e}");
        }
    }
    Ok(())
}

/// Echo text to channel
#[poise::command(slash_command, required_permissions = "MANAGE_MESSAGES")]
pub async fn say(ctx: Context<'_>, #[description = "Message to send"] text: String) -> Result<()> {
    // Acknowledge the interaction with an invisible ephemeral reply, delete it,
    // then post the actual text as a normal channel message (not a reply to the
    // command invocation).
    let ack = ctx
        .send(
            poise::CreateReply::default()
                .content("\u{200b}")
                .ephemeral(true),
        )
        .await?;
    if let Err(e) = ack.delete(ctx).await {
        warn!("say: failed to delete ephemeral acknowledgement: {e}");
    }

    ctx.channel_id()
        .say(ctx.serenity_context(), &text)
        .await?;
    Ok(())
}

pub fn commands() -> Vec<poise::Command<Data, Error>> {
    vec![
        compress(),
        convert(),
        upload(),
        search(),
        download(),
        say(),
        message_upload(),
        message_compression(),
        message_download(),
    ]
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn safe_basename_strips_directories() {
        assert_eq!(safe_basename("/music/foo.mp3"), "foo.mp3");
        assert_eq!(safe_basename("../../etc/passwd"), "passwd");
        assert_eq!(
            safe_basename(r"..\..\windows\system32\evil.exe"),
            "evil.exe"
        );
        assert_eq!(safe_basename(r"C:\Users\x\song.mp3"), "song.mp3");
    }

    #[test]
    fn safe_basename_never_returns_dot_entries() {
        assert_eq!(safe_basename(".."), "file");
        assert_eq!(safe_basename("."), "file");
        assert_eq!(safe_basename(""), "file");
    }
}