extern crate dotenvy;
extern crate lastfm;
extern crate reqwest;
extern crate reqwest_middleware;
use http_cache_reqwest::{CACacheManager, Cache, CacheMode, HttpCache, HttpCacheOptions};

use serenity::async_trait;
use serenity::builder::{CreateAttachment, CreateMessage};
use serenity::model::channel::Message;
use serenity::model::id::UserId;
use serenity::prelude::*;

extern crate magick_rust;
use magick_rust::{ColorspaceType, CompositeOperator, MagickWand, PixelWand, magick_wand_genesis, FilterType};

use std::env;
use std::sync::Once;

use palette::color_difference::ImprovedCiede2000;
use palette::lab::Lab;
use palette::white_point::D65;

extern crate sqlx;
use sqlx::sqlite::SqlitePool;

use imagetext::fontdb::FontDB;
use imagetext::superfont::SuperFont;

mod text;

static START: Once = Once::new();

struct Handler;

enum Reply {
    Image(Vec<u8>),
    Text(String),
}

macro_rules! now {
    () => {
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs_f32() as usize
    };
}

macro_rules! log {
	($a:expr) => {
		if env::var("DEBUG").unwrap_or("0".to_string()) == "1" {
			println!(concat!("debug: {} ", $a), now!())
		}
	};

	($a:expr, $($b:expr),+) => {
		if env::var("DEBUG").unwrap_or("0".to_string()) == "1" {
			println!(concat!("debug: {} ", $a), now!(), $($b),+)
		}
	};
}

macro_rules! handle_magick_result {
    ($a: expr, $b: literal) => {
        match $a {
            Ok(_) => {
                log!("{} run successfully", stringify!($a));
            }
            Err(e) => return Reply::Text(format!("Error: {} {}", $b, e)),
        }
    };
}

macro_rules! handle_magick_option {
    ($a: expr, $b: literal) => {
        match $a {
            Some(res) => res,
            None => return Reply::Text($b.to_string()),
        }
    };
}

// this function is almost assuredly the least idiomatic rust code I will ever write.
// but until I know what the "correct" way is, it'll have to do
fn parse_cielab(s: String) -> Result<(f32, f32, f32), &'static str> {
    if s.len() < 13 || &s[0..7] != "cielab(" || s.chars().nth(s.len() - 1).unwrap() != ')' {
        return Err("Error parsing cielab string");
    }
    let vals = s[7..(s.len() - 1)]
        .split(",")
        .map(|x| match x.parse() {
            Ok(f) => f,
            Err(_) => f32::NAN,
        })
        .collect::<Vec<f32>>();
    if vals.iter().any(|x| x.is_nan()) {
        return Err("Error parsing cielab string");
    }
    match &vals[..] {
        &[a, b, c] => Ok((a, b, c)),
        _ => Err("Error parsing cielab string"),
    }
}

fn validate_color(col: &PixelWand) -> Option<Lab> {
    let color_str = match col.get_color_as_string() {
        Ok(s) => s,
        Err(_) => return None,
    };
    let color_raw = match parse_cielab(color_str) {
        Ok(f) => f,
        Err(_) => return None,
    };
    Some(Lab::<D65>::from_components(color_raw))
}

async fn art(ctx: &Context, arg: &str, id: UserId) -> Reply {
    let lastfm_user = match arg {
        "" => get_lastfm_username(ctx, id).await,
        _ => Some(arg.to_string()),
    };
    let lastfm_client = match lastfm_user {
        Some(s) => lastfm::Client::<String, String>::from_env(s),
        None => return Reply::Text("No last.fm username set.".to_string()),
    };
    let now_playing = match lastfm_client.now_playing().await {
        Ok(np) => np,
        Err(e) => return Reply::Text(format!("Error: grabbing last.fm user data failed {e}")),
    };
	let track = match now_playing {
        Some(track) => track,
        None => return Reply::Text("Nothing playing.".to_string()),
    };
    let track_art = match track.image.extralarge {
    	Some(track_art) => track_art,
    	None => return Reply::Text("Error: getting image uri failed".to_string()),
    };
    Reply::Text(track_art.to_string())
}

async fn url(ctx: &Context, arg: &str, id: UserId) -> Reply {
    let lastfm_user = match arg {
        "" => get_lastfm_username(ctx, id).await,
        _ => Some(arg.to_string()),
    };
    let lastfm_client = match lastfm_user {
        Some(s) => lastfm::Client::<String, String>::from_env(s),
        None => return Reply::Text("No last.fm username set.".to_string()),
    };
    let now_playing = match lastfm_client.now_playing().await {
        Ok(np) => np,
        Err(e) => return Reply::Text(format!("Error: grabbing last.fm user data failed {e}")),
    };
	let track = match now_playing {
        Some(track) => track,
        None => return Reply::Text("Nothing playing.".to_string()),
    };
    Reply::Text(track.url)
}

async fn fmi(ctx: &Context, arg: &str, id: UserId, avatar: Option<String>) -> Reply {
    let lastfm_user = match arg {
        "" => get_lastfm_username(ctx, id).await,
        _ => Some(arg.to_string()),
    };
    let lastfm_client = match lastfm_user {
        Some(s) => lastfm::Client::<String, String>::from_env(s),
        None => return Reply::Text("No last.fm username set.".to_string()),
    };
    let now_playing = match lastfm_client.now_playing().await {
        Ok(np) => np,
        Err(e) => return Reply::Text(format!("Error: grabbing last.fm user data failed {e}")),
    };
    let track = match now_playing {
        Some(track) => track,
        None => return Reply::Text("Nothing playing.".to_string()),
    };
    let track_info = text::TrackInfo {
    	title: track.name,
    	artist: track.artist.name,
    	album: track.album,
    };
    let image_uri = match track.image.extralarge {
        Some(iu) => iu,
        None => return Reply::Text("Error: getting image uri failed".to_string()),
    };

    let image = match get_image(ctx, image_uri.as_str()).await {
        Ok(i) => i,
        Err(e) => return Reply::Text(format!("{e}")),
    };
    let mut base_color = PixelWand::new();
    let mut white = PixelWand::new();
    let main_wand = MagickWand::new();
    let art_wand = MagickWand::new();
    let mut art_wand_cluster = MagickWand::new();
    let mask_wand = MagickWand::new();
    let text_image_wand = MagickWand::new();

    handle_magick_result!(
        base_color.set_color("#7f7f7f"),
        "Failed to set init base color"
    );
    handle_magick_result!(
        art_wand.read_image_blob(image),
        "Failed to read image from uri"
    );
    handle_magick_result!(
        art_wand.transform_image_colorspace(ColorspaceType::Lab),
        "Failed to set art colorspace"
    );

    let (art_width, art_height) = (art_wand.get_image_width(), art_wand.get_image_height());
    handle_magick_result!(
        art_wand_cluster.new_image(art_width, art_height, &base_color),
        "Failed to init cluster image"
    );
    handle_magick_result!(
        art_wand_cluster.compose_images(&art_wand, CompositeOperator::SrcOver, true, 0, 0),
        "Failed to copy onto cluster image"
    );
    // least stupid way I could figure out to do this, since it seems that MagickWand::new_from_wand() doesn't work
    handle_magick_result!(
        art_wand_cluster.set_image_colorspace(ColorspaceType::Lab),
        "Failed to set cluster colorspace"
    );
    handle_magick_result!(
        art_wand_cluster.kmeans(10, 200, 0.001),
        "Failed to run kmeans"
    );
    let mut colors = handle_magick_option!(
        art_wand_cluster.get_image_histogram(),
        "Failed to get color histogram"
    );
    colors.sort_by_cached_key(|color| -(color.get_color_count() as isize));
    let base_lab = validate_color(&colors[0]).expect("Failed to validate base color");
    let other_colors = colors
        .iter()
        .filter_map(|col| {
            let testing_color = validate_color(col)?;
            match testing_color.improved_difference(base_lab) {
                10.0.. => Some(testing_color),
                _ => None,
            }
        })
        .collect::<Vec<_>>();
    let mut accent_color = PixelWand::new();
    handle_magick_result!(
        accent_color.set_color("cielab(0.0,0.0,0.0)"),
        "Failed to init accent color"
    );
    if let Some(color) = other_colors.first() {
        let col = format!("cielab{:?}", color.into_components());
        handle_magick_result!(
            accent_color.set_color(col.as_str()),
            "Failed to set accent color"
        );
    }

    
    let use_dark_color = match validate_color(&colors[0]) {
    	Some(color) => {
   			let black_delta_e = Lab::<D65>::new(0.0, 0.0, 0.0).improved_difference(color);
   			let white_delta_e = Lab::<D65>::new(100.0, 0.0, 0.0).improved_difference(color);
    		black_delta_e > white_delta_e
    	}
    	_ => false
    };

    handle_magick_result!(white.set_color("#ffffff"), "Failed to init white");
    handle_magick_result!(
        mask_wand.read_image_blob(include_bytes!("accent_mask.png")),
        "Failed to load mask"
    );
    handle_magick_result!(
        mask_wand.opaque_paint_image(&white, &accent_color, 0.0, false),
        "Failed to paint accent mask"
    );

    let avatar_wand = MagickWand::new();
    match avatar {
        Some(avatar_uri) => {
            if let Ok(avatar) = get_image(ctx, avatar_uri.as_str()).await {
                handle_magick_result!(
                    avatar_wand.read_image_blob(avatar),
                    "Failed to load user avatar"
                );
            } else {
                handle_magick_result!(
                    avatar_wand.new_image(100, 100, &white),
                    "Failed to load dummy avatar"
                );
            }
        }
        None => handle_magick_result!(
            avatar_wand.new_image(100, 100, &white),
            "Failed to load dummy avatar"
        ),
    }
    let avatar_mask_wand = MagickWand::new();
    handle_magick_result!(
        avatar_mask_wand.read_image_blob(include_bytes!("avatar_mask.png")),
        "Failed to load avatar mask"
    );
    handle_magick_result!(
        avatar_wand.compose_images(&avatar_mask_wand, CompositeOperator::CopyAlpha, false, 0, 0),
        "Failed to mask avatar"
    );
    handle_magick_result!(
        avatar_wand.resize_image(64, 64, FilterType::RobidouxSharp),
        "Failed to resize avatar"
    );
    handle_magick_result!(
        avatar_wand.transform_image_colorspace(ColorspaceType::Lab),
        "Failed to set avatar colorspace"
    );

	let (image_width, image_height) = (548, 147);
    let data = ctx.data.write().await;
    let fonts = data
        .get::<FontsHaver>().expect("Failed to load fonts");
    let text_image_blob = match text::fmi_text(image_width, image_height, track_info, fonts, 19.0, use_dark_color) {
    	Ok(bytes) => bytes,
    	Err(e) => return Reply::Text(e),
    };
    handle_magick_result!(text_image_wand.read_image_blob(&text_image_blob), "Failed to load text image");
    handle_magick_result!(
        text_image_wand.transform_image_colorspace(ColorspaceType::Lab),
        "Failed to set avatar colorspace"
    );

    handle_magick_result!(
        main_wand.new_image(image_width as usize, image_height as usize, &colors[0]),
        "Failed to create wand"
    );
    handle_magick_result!(
        main_wand.transform_image_colorspace(ColorspaceType::Lab),
        "Failed to set main colorspace"
    );
    handle_magick_result!(
        art_wand.adaptive_resize_image(124, 124),
        "Failed to resize art"
    );
    handle_magick_result!(
        art_wand_cluster.adaptive_resize_image(124, 124),
        "Failed to resize art_cluster"
    );
    handle_magick_result!(
        main_wand.compose_images(&art_wand, CompositeOperator::SrcOver, false, 12, 12),
        "Failed to combine art image"
    );
    handle_magick_result!(
        main_wand.compose_images(&mask_wand, CompositeOperator::SrcOver, false, 401, 0),
        "Failed to combine mask"
    );
    #[cfg(debug_assertions)]
    if env::var("DEBUG_IMAGE").unwrap_or("0".to_string()) == "1" {
    	handle_magick_result!(
    	    main_wand.compose_images(
    	        &art_wand_cluster,
    	        CompositeOperator::SrcOver,
    	        false,
    	        160,
    	        12
    	    ),
    	    "Failed to combine debug image"
    	);
    }
    handle_magick_result!(
        main_wand.compose_images(&text_image_wand, CompositeOperator::SrcOver, false, 0, 0),
        "Failed to combine mask"
    );
    handle_magick_result!(
        main_wand.compose_images(&avatar_wand, CompositeOperator::SrcOver, false, 473, 73),
        "Failed to combine avatar image"
    );
    Reply::Image(main_wand.write_image_blob("png").unwrap())
}

async fn set(ctx: &Context, arg: &str, id: UserId) -> Reply {
    set_lastfm_username(ctx, id, arg.to_string()).await;
    Reply::Text(format!("set user {arg}"))
}

#[async_trait]
impl EventHandler for Handler {
    async fn message(&self, ctx: Context, msg: Message) {
        let mut cmd_iter = msg.content.split(" ");
        let cmd = cmd_iter.next().unwrap_or("");
        let arg1 = cmd_iter.next().unwrap_or("");
        let arg2 = cmd_iter.next().unwrap_or("");
        let resp = match (cmd, arg1, arg2) {
            (".set", arg, "") | (".k", "set", arg) | (".kset", arg, "") => {
                log!("{} received", msg.content);
                Some(set(&ctx, arg, msg.author.id).await)
            },
            (".k", "art", arg) | (".k", arg, "art") | (".ka" | ".kart", arg, "") => {
            	log!("{} received", msg.content);
            	Some(art(&ctx, arg, msg.author.id).await)
            },
            (".k", "url" | "uri" | "link", arg) | (".k", arg, "url" | "uri" | "link") | (".ku" | ".kl" | ".kurl", arg, "") => {
            	log!("{} received", msg.content);
            	Some(url(&ctx, arg, msg.author.id).await)
            },
            (".fmi" | ".k" | ".kf" | ".ki" | ".kfmi", arg, "") | (".k", "fm" | "fmi" | "get" | "img", arg) => {
                log!("{} received", msg.content);
                Some(fmi(&ctx, arg, msg.author.id, msg.author.avatar_url()).await)
            },
            _ => None,
        };
        if let Some(reply) = resp {
            let m = match reply {
                Reply::Image(img) => {
                    let file = CreateAttachment::bytes(img, "fmi.png");
                    CreateMessage::new().add_file(file)
                }
                Reply::Text(txt) => CreateMessage::new().content(txt),
            };

            let message = msg.channel_id.send_message(&ctx.http, m).await;
            if let Err(why) = message {
                println!("Error sending message: {why:?}");
            }
        }
    }
}

struct HttpHaver;
impl TypeMapKey for HttpHaver {
    type Value = reqwest_middleware::ClientWithMiddleware;
}

struct PoolHaver;
impl TypeMapKey for PoolHaver {
    type Value = SqlitePool;
}

struct FontsHaver;
impl TypeMapKey for FontsHaver {
	type Value = (SuperFont<'static>, SuperFont<'static>);
}

struct DBResponse {
    lastfm_username: String,
}

async fn get_lastfm_username(ctx: &Context, id: UserId) -> Option<String> {
    log!("get db user {}", id);
    let data = ctx.data.write().await;
    let pool = data
        .get::<PoolHaver>()
        .expect("Failed to get pool container");
    let id = i64::from(id);
    let resp = sqlx::query_as!(
        DBResponse,
        r#"
			SELECT lastfm_username
			FROM users
			WHERE discord_userid = ?1
		"#,
        id
    )
    .fetch_one(pool)
    .await;
    match resp {
        Ok(r) => {
            log!("got user {}", r.lastfm_username);
            Some(r.lastfm_username)
        }
        Err(_) => None,
    }
}

async fn set_lastfm_username(ctx: &Context, id: UserId, user: String) {
    log!("set db user {} {}", id, user);
    let data = ctx.data.write().await;
    let pool = data
        .get::<PoolHaver>()
        .expect("Failed to get pool container");
    let id = i64::from(id);
    sqlx::query!(
        r#"
			INSERT INTO users
			VALUES (?1, ?2)
		"#,
        id,
        user
    )
    .execute(pool)
    .await
    .expect("Failed to insert");
}

async fn get_image(ctx: &Context, url: &str) -> Result<Vec<u8>, reqwest_middleware::Error> {
    log!("get {}", url);
    let data = ctx.data.write().await;
    let http = data
        .get::<HttpHaver>()
        .expect("Failed to get http client");
    match http.get(url).send().await {
        Ok(resp) => {
            log!("response received");
            Ok(resp
                .bytes()
                .await
                .expect("Unable to resolve bytes")
                .to_vec())
        }
        Err(e) => Err(e),
    }
}

#[tokio::main]
async fn main() {
    START.call_once(|| {
        dotenvy::dotenv().expect("Failed to load .env");
        magick_wand_genesis();
    });

    let db_url = env::var("DATABASE_URL").expect("Failed to load DATABASE_URL");
    let pool = SqlitePool::connect(&db_url)
        .await
        .expect("Failed to load db");

    let token = env::var("DISCORD_TOKEN").expect("Failed to load DISCORD_TOKEN");
    // Set gateway intents, which decides what events the bot will be notified about
    let intents = GatewayIntents::GUILD_MESSAGES
        | GatewayIntents::DIRECT_MESSAGES
        | GatewayIntents::MESSAGE_CONTENT;

    let http = reqwest_middleware::ClientBuilder::new(reqwest::Client::new())
        .with(Cache(HttpCache {
            mode: CacheMode::Default,
            manager: CACacheManager::default(),
            options: HttpCacheOptions::default(),
        }))
        .build();

   	FontDB::load_from_dir("fonts"); //singlet instance??? wha?????
    let regular_fonts = FontDB::query("
    	NotoSans-Regular
    	NotoSansHK-Regular
    	NotoSansJP-Regular
    	NotoSansKR-Regular
    	NotoSansSC-Regular
    	NotoSansTC-Regular
    	NotoSansArabic-Regular
    	Heebo-Regular
    	NotoEmoji-Regular
    	Symbola
    	Unifont
    ").expect("Failed to load regular fonts");
    let bold_fonts = FontDB::query("
    	NotoSans-SemiBold
    	NotoSansJP-Medium
    	NotoSansKR-Medium
    	NotoSansSC-Medium
    	NotoSansTC-Medium
    	NotoSansArabic-SemiBold
    	Heebo-SemiBold
    	NotoEmoji-Medium
    	Symbola
    	Unifont
    ").expect("Failed to load bold fonts");

    let mut discord_client = Client::builder(&token, intents)
        .event_handler(Handler)
        .await
        .expect("Err creating Discord client");

    {
        let mut data = discord_client.data.write().await;
        data.insert::<PoolHaver>(pool);
        data.insert::<HttpHaver>(http);
        data.insert::<FontsHaver>((regular_fonts, bold_fonts));
    }

    if let Err(why) = discord_client.start().await {
        println!("Client error: {why:?}");
    }
}