use std::{net::TcpListener, process, sync::Arc};

use http::responses::{Body, Response};

use resvg::{
    tiny_skia::{Color, Pixmap, Transform},
    usvg,
};

mod constants;
mod handlers;
mod http;
mod icons;
mod macros;
mod threads;

fn main() {
    println!("luciders starting...");

    let port = match std::env::var("PORT") {
        Ok(port) => port,
        Err(_) => "7878".to_string(),
    };

    let listener = TcpListener::bind(format!("[::]:{}", port))
        .unwrap_or_else(|_| fatal("Failed to bind to address"));

    let icons_rc = Arc::new(match icons::Icons::build() {
        Ok(icons) => icons,
        Err(e) => fatal(e),
    });

    let mut handlers = handlers::Handlers::new();

    handlers.add_handler("/", |req| {
        if req.method != "GET" {
            return Response::new(req, 405, Body::Static("Method Not Allowed"));
        }

        Response::new(req, 200, Body::Static("OK - luciders is running"))
    });

    handlers.add_handler("/info", |req| {
        if req.method != "GET" {
            return Response::new(req, 405, Body::Static("Method Not Allowed"));
        }

        Response::new(req, 200, Body::Static(constants::SERVER_INFO))
    });

    handlers.add_handler("/icons/[icon].svg", {
        let icons = Arc::clone(&icons_rc);
        move |req| {
            if req.method != "GET" {
                return Response::new(req, 405, Body::Static("Method Not Allowed"));
            }

            let icon_filename = match req.url.get_path_segment(1) {
                Some(icon) => icon,
                None => return Response::new(req, 404, Body::Static("Icon Segment Not Found")),
            };

            let icon_name = &icon_filename[..icon_filename.len() - icons::ICON_FILE_EXTENSION_LEN];

            if !icons.has_iconname(icon_name) {
                return Response::new(req, 404, Body::Static("Icon Not Found"));
            }

            let icon = match icons.get_icon(icon_name) {
                Some(icon) => icon,
                None => {
                    error!("Failed to read icon");
                    return Response::new(req, 500, Body::Static("Failed to read icon"));
                }
            };

            return Response::new(req, 200, Body::Bytes(icon, "image/svg+xml"));
        }
    });

    handlers.add_handler("/icons/[icon].png", {
        let icons = Arc::clone(&icons_rc);
        move |req| {
            if req.method != "GET" {
                return Response::new(req, 405, Body::Static("Method Not Allowed"));
            }

            let icon_filename = match req.url.get_path_segment(1) {
                Some(icon) => icon,
                None => return Response::new(req, 404, Body::Static("Icon Segment Not Found")),
            };

            let icon_name = &icon_filename[..icon_filename.len() - icons::ICON_FILE_EXTENSION_LEN];

            if !icons.has_iconname(icon_name) {
                return Response::new(req, 404, Body::Static("Icon Not Found"));
            }

            let mut icon_string = match icons.get_icon_string(icon_name) {
                Some(icon) => icon,
                None => {
                    error!("Failed to read icon");
                    return Response::new(req, 500, Body::Static("Failed to read icon"))
                },
            };

            // Options handling
            let mut scale = 1;
            match req.url.query.get("scale") {
                Some(scale_str) => {
                    match scale_str.parse::<u32>() {
                        Ok(scale_val) => {
                            if scale_val <= 0 || scale_val > 100 {
                                return Response::new(req, 400, Body::Static("Invalid scale value. Scale value must be an integer > 0 and <= 100"));
                            }
                            scale = scale_val;
                        }
                        Err(_) => return Response::new(req, 400, Body::Static("Invalid scale value. Scale value must be an integer > 0 and <= 100"))
                    }
                }
                None => {}
            }

            let mut padding = 0;
            match req.url.query.get("padding") {
                Some(padding_str) => {
                    match padding_str.parse::<u32>() {
                        Ok(padding_val) => {
                            if padding_val > 100 {
                                return Response::new(req, 400, Body::Static("Invalid padding value. Padding value must be an integer >= 0 and <= 100"));
                            }

                            padding = padding_val;
                        }
                        Err(_) => return Response::new(req, 400, Body::Static("Invalid padding value. Padding value must be an integer >= 0 and <= 100"))
                    }
                }
                None => {}
            }

            match req.url.query.get("discord_compatibility") {
                Some(_) => {
                    padding = 8;
                }
                None => {}
            }

            let mut background = Color::TRANSPARENT;
            match req.url.query.get("background") {
                Some(background_str) => {
                    match u32::from_str_radix(&background_str, 16) {
                        Ok(background_val) => {
                            if background_val > 0xFFFFFF {
                                return Response::new(req, 400, Body::Static("Invalid background value. Background value must be a valid hex color #000000 - #FFFFFF"));
                            }
                            let red = ((background_val >> 16) & 0xFF) as u8;
                            let green = ((background_val >> 8) & 0xFF) as u8;
                            let blue = (background_val & 0xFF) as u8;
                            background = Color::from_rgba8(red, green, blue, 255);
                        }
                        Err(_) => return Response::new(req, 400, Body::Static("Invalid background value. Background value must be a valid hex color"))
                    }
                }
                None => {}
            }

            let mut svg_stroke = "currentColor";
            // thx horizell for this code
            match (req.url.query.get("stroke_color"), req.url.query.get("stroke_colour"), req.url.query.get("stroke")) {
                (Some(stroke_str), _, _) | (_, Some(stroke_str), _) | (_, _, Some(stroke_str)) => svg_stroke = stroke_str,
                _ => {}
              }

            icon_string = icon_string.replace("currentColor", &svg_stroke);

            let mut backwards_compatibility = false;
            match req.url.query.get("backwards_compatibility") {
                Some(_) => {
                    backwards_compatibility = true;
                    // Icons were 80x80 plus 8px of padding; Icons start at 24x24 now so: 80 - 8 = 72, 72 / 24 = 3 therefore scale is 3x.
                    scale = 3;
                    padding = 8;

                }
                None => {}
            }

            // Rendering
            let tree = match usvg::Tree::from_str(&icon_string, &usvg::Options::default()) {
                Ok(tree) => tree,
                Err(e) => {
                    error!(&format!("Failed to load icon into tree: {}", e));
                    return Response::new(req, 500, Body::Static("Failed to load icon into tree"))
                }
            };


            let length = if backwards_compatibility { 80 } else { 24 * scale + padding };

            let mut pixmap = match Pixmap::new(length, length) {
                Some(pixmap) => pixmap,
                None => {
                    error!("Failed to create pixmap");
                    return Response::new(req, 500, Body::Static("Failed to create pixmap"))
                },
            };

            let mut pixmap_mut = pixmap.as_mut();
            pixmap_mut.fill(background);

            resvg::render(
                &tree,
                    Transform::from_scale(scale as f32, scale as f32)
                    .post_concat(Transform::from_translate(length as f32 / 2.0 - 12.0 * scale as f32, length as f32 / 2.0 - 12.0 * scale as f32)),
                &mut pixmap_mut,
            );
            let png = match pixmap.encode_png() {
                Ok(png) => png,
                Err(e) => {
                    error!(&format!("Failed to encode PNG: {}", e));
                    return Response::new(req, 500, Body::Static("Failed to encode PNG"))
                },
            };

            return Response::new(req, 200, Body::Bytes(png, "image/png"));
        }
    });

    handlers
        .bind(listener)
        .unwrap_or_else(|_| fatal("Failed to bind handlers"));

    println!("luciders started on port {}", port);
    println!("Serving {} icons", icons_rc.icons_len())
}

fn fatal(msg: &'static str) -> ! {
    eprintln!("[FATAL] {}", msg);
    process::exit(1);
}