import { GlobalFonts, createCanvas, loadImage } from '@napi-rs/canvas';
import { levelingService } from '@/modules/leveling/leveling.service';
import path from 'path';

// Register Fonts
const fontDir = path.join(process.cwd(), 'src', 'assets', 'fonts');
GlobalFonts.registerFromPath(path.join(fontDir, 'IBMPlexSansCondensed-SemiBold.ttf'), 'IBMPlexSansCondensed-SemiBold');
GlobalFonts.registerFromPath(path.join(fontDir, 'IBMPlexMono-Bold.ttf'), 'IBMPlexMono-Bold');

const textColor = '#FFE7C5';
const secondaryTextColor = '#9C7D53';
const accentColor = '#3F2923';

interface StudentCardData {
    username: string;
    avatarUrl: string;
    id: string;
    level: number;
    au: bigint; // Astral Units
    cu: bigint; // Constellation Units
    xp: bigint; // Experience
    className?: string | null;
}

export async function generateStudentIdCard(data: StudentCardData): Promise<Buffer> {
    const templatePath = path.join(process.cwd(), 'src', 'assets', 'student-id-template.png');
    const template = await loadImage(templatePath);

    const canvas = createCanvas(template.width, template.height);
    const ctx = canvas.getContext('2d');

    // Draw Template
    ctx.drawImage(template, 0, 0);

    // Draw Avatar
    const avatarSize = 111;
    const avatarX = 18;
    const avatarY = 64;

    try {
        const avatar = await loadImage(data.avatarUrl);
        ctx.save();
        ctx.beginPath();
        // Square avatar
        ctx.rect(avatarX, avatarY, avatarSize, avatarSize);
        ctx.clip();
        ctx.drawImage(avatar, avatarX, avatarY, avatarSize, avatarSize);
        ctx.restore();
    } catch (e) {
        console.error("Failed to load avatar", e);
    }

    // Draw ID
    ctx.save();
    ctx.font = '12px IBMPlexMono-Bold';
    ctx.fillStyle = secondaryTextColor;
    ctx.textAlign = 'left';
    ctx.fillText(`ID: ${data.id}`, 302, 30);
    ctx.restore();

    // Draw Username
    ctx.save();
    ctx.font = '32px IBMPlexSansCondensed-SemiBold';
    ctx.fillStyle = textColor;
    ctx.textAlign = 'left';
    ctx.fillText(data.username, 140, 107);
    ctx.restore();

    // Draw Class
    try {
        const classBadge = await loadImage(path.join(process.cwd(), 'src', 'assets', 'student-id-class-badge.png'));
        ctx.save();
        ctx.beginPath();
        ctx.drawImage(classBadge, 100, 126, 58, 58);
        ctx.font = '32px IBMPlexMono-Bold';
        ctx.fillStyle = textColor;
        ctx.textAlign = 'left';
        ctx.fillText(data.className || 'Unknown', 120, 162);
        ctx.restore();
    } catch (e) {
        console.error("Failed to load class badge", e);
    }

    // Draw Astral Units
    ctx.save();
    ctx.font = '32px IBMPlexMono-Bold';
    ctx.fillStyle = textColor;
    ctx.textAlign = 'left';
    ctx.fillText(data.au.toString(), 163, 218);
    ctx.restore();

    // Draw Constellation Units
    ctx.save();
    ctx.font = '32px IBMPlexMono-Bold';
    ctx.fillStyle = textColor;
    ctx.textAlign = 'left';
    ctx.fillText(data.cu.toString(), 163, 153);
    ctx.restore();

    // Draw Level
    ctx.save();
    // check how many digits the level has and adjust the position accordingly
    const levelDigits = data.level.toString().length;
    ctx.font = '12px IBMPlexMono-Bold';
    ctx.fillStyle = secondaryTextColor;
    ctx.textAlign = 'left';
    if (levelDigits === 1) {
        ctx.fillText(data.level.toString(), 406, 265);
    } else {
        ctx.fillText(data.level.toString(), 400, 265);
    }
    ctx.restore();

    // Draw Next Level
    ctx.save();
    // check how many digits the next level has and adjust the position accordingly
    const nextLevelDigits = (data.level + 1).toString().length;
    ctx.font = '24px IBMPlexMono-Bold';
    ctx.fillStyle = textColor;
    ctx.textAlign = 'left';
    if (nextLevelDigits === 1) {
        ctx.fillText((data.level + 1).toString(), 438, 255);
    } else {
        ctx.fillText((data.level + 1).toString(), 431, 255);
    }
    ctx.restore();

    // Draw xp bar
    const xpbarX = 2;
    const xpbarY = 268;
    const xpbarMaxWidth = 400; // in pixels
    const xpbarHeight = 4;

    const xp = data.xp;
    const requiredXp = BigInt(levelingService.getXpForLevel(data.level));

    // Check to avoid division by zero, though requiredXp should be >= 100
    let percentage = 0;
    if (requiredXp > 0n) {
        percentage = Number(xp) / Number(requiredXp);
    }

    const xpFilledWidth = Math.min(Math.max(percentage * xpbarMaxWidth, 0), xpbarMaxWidth);

    const gradient = ctx.createLinearGradient(xpbarX, xpbarY, xpbarX + xpFilledWidth, xpbarY);
    gradient.addColorStop(0, '#FFFFFF');
    gradient.addColorStop(1, '#D9B178');
    ctx.save();
    ctx.fillStyle = accentColor;
    ctx.fillRect(xpbarX, xpbarY, xpbarMaxWidth, xpbarHeight);

    if (xpFilledWidth > 0) {
        ctx.fillStyle = gradient;
        ctx.fillRect(xpbarX, xpbarY, xpFilledWidth, xpbarHeight);
    }
    ctx.restore();

    return canvas.toBuffer('image/png');
}