use crate::{
  Error,
  internals::utils::{
    mention_dev,
    format_bytes
  }
};

use regex::Regex;
use std::{
  os::unix::fs::MetadataExt,
  fs::{
    write,
    remove_file,
    metadata
  }
};
use poise::{
  CreateReply,
  serenity_prelude::CreateAttachment
};

/// Convert MIDI file to WAV
#[poise::command(context_menu_command = "MIDI -> WAV")]
pub async fn midi_to_wav(
  ctx: poise::Context<'_, (), Error>,
  #[description = "MIDI file to be converted"] message: poise::serenity_prelude::Message
) -> Result<(), Error> {
  let re = Regex::new(r"(?i)\.mid$").unwrap();

  if !message.embeds.is_empty() || message.attachments.is_empty() || !re.is_match(&message.attachments[0].filename) {
    ctx.reply("That ain't a MIDI file! What are you even doing??").await?;
    return Ok(());
  }

  ctx.defer().await?;

  let bytes = match message.attachments[0].download().await {
    Ok(bytes) => bytes,
    Err(y) => {
      ctx.send(CreateReply::default()
        .content(format!(
          "Download failed, ask {} to check console for more information!",
          mention_dev(ctx).unwrap_or_default()
        ))
      )
      .await.unwrap();

      return Err(Error::from(format!("Failed to download the file: {}", y)))
    }
  };

  let midi_path = &message.attachments[0].filename;
  write(midi_path, bytes)?;

  let wav_path = re.replace(&midi_path, ".wav");

  let sf2_path = "/tmp/FluidR3_GM.sf2";
  write(sf2_path, include_bytes!("../internals/assets/FluidR3_GM.sf2"))?;

  let output = std::process::Command::new("fluidsynth")
    .args(&["-ni", sf2_path, midi_path, "-F", &wav_path])
    .output();

  // Just to add an info to console to tell what the bot is doing when MIDI file is downloaded.
  println!("Discord[{}:{}]: Processing MIDI file: \"{}\"", ctx.guild().unwrap().name, ctx.command().qualified_name, midi_path);

  match output {
    Ok(_) => {
      let reply = ctx.send(CreateReply::default()
        .attachment(CreateAttachment::path(&*wav_path).await.unwrap())
      ).await;

      if reply.is_err() {
        println!(
          "Discord[{}:{}]: Processed file couldn't be uploaded back to Discord channel due to upload limit",
          ctx.guild().unwrap().name, ctx.command().qualified_name
        );

        ctx.send(CreateReply::default()
          .content(format!(
            "Couldn't upload the processed file (`{}`, `{}`) due to upload limit",
            &*wav_path, format_bytes(metadata(&*wav_path).unwrap().size())
          ))
        ).await.unwrap();
      } else if reply.is_ok() {
        remove_file(midi_path)?;
        remove_file(&*wav_path)?;
      }
    },
    Err(y) => {
      ctx.send(CreateReply::default()
        .content("Command didn't execute successfully, check console for more information!")
      ).await.unwrap();

      return Err(Error::from(format!("Midi conversion failed: {}", y)))
    }
  }

  Ok(())
}