let colors = {};
let rasterized = {};

function get_color(stage_name) {
    if (stage_name in config.predefined_colors) {
        return config.predefined_colors[stage_name];
    }

    if (stage_name in colors) {
        return colors[stage_name];
    }

    const r = Math.floor(Math.random() * 155);
    const g = Math.floor(Math.random() * 155);
    const b = Math.floor(Math.random() * 155);

    colors[stage_name] = [ 100 + r, 100 + g, 100 + b ];

    return colors[stage_name];
}

function rasterize_and_pack(text, cycles) {
    // TODO: handle texture is full or stuff don't fit (unlikely)

    const key = text + '@' + cycles;

    if (key in rasterized) {
        return rasterized[key];
    }

    let cycles_total_padding = (cycles - 1) * config.padding;
    let bonus_cells = Math.ceil(cycles_total_padding / config.w);

    const tiles_needed = 1; // cycles - 1 + 1 + bonus_cells; // stage name + count cycles from one
    if (tiles_needed > config.raster_texture_size / config.w - raster_tile.x) {
        raster_tile.x = 0;
        raster_tile.y += 1;
    }

    const u = raster_tile.x * config.w / config.raster_texture_size;
    const v = raster_tile.y * config.h / config.raster_texture_size;

    rasterize(text);    
    gl.bindTexture(gl.TEXTURE_2D, textures['raster']);
    gl.texSubImage2D(gl.TEXTURE_2D, 0, 
        raster_tile.x * config.w, raster_tile.y * config.h, 
        config.w, config.h, 
        gl.RGBA, gl.UNSIGNED_BYTE, 
        c2d.canvas
    );

    raster_tile.x += 1;

    /*
    raster_tile.x += cycles + bonus_cells;

    if (raster_tile.x === config.raster_texture_size / config.w) {
        raster_tile.x = 0;
        raster_tile.y += 1;
    }
    */

    rasterized[key] = [u, v];

    return [u, v];
}

function pack_instruction(instruction, positions, sizes, colors, uvs, starts, y) {
    starts.push(positions.length);
    
    for (let i = 0; i < instruction.lanes['0'].length; ++i) {
        const stage = instruction.lanes['0'][i];
        let stage_cycles;

        if (i < instruction.lanes['0'].length - 1) {
            const next_stage = instruction.lanes['0'][i + 1];
            stage_cycles = next_stage.c - stage.c;
        } else {
            stage_cycles = instruction.retcyc - stage.c;
        }

        let [r, g, b] = get_color(stage.name);
        let a = 255;

        if (!instruction.retired) {
            r = Math.max(50, r - 50);
            g = Math.max(50, g - 50);
            b = Math.max(50, b - 50);
            a = 100;
        }

        const [u, v] = rasterize_and_pack(stage.name, stage_cycles);

        sizes.push(stage_cycles * config.w + (stage_cycles - 1) * config.padding, 1 * config.h);
        positions.push(config.w * stage.c + config.padding * (stage.c - 1), config.h * y + config.padding * (y - 1)); 
        colors.push(r, g, b, a);
        uvs.push(u, v);
    }

    return instruction.lanes['0'].length;
}

function generate(trace_id) {
    const before = performance.now();

    const result = {
        'count': 0,
    };

    const positions = [];
    const sizes = [];
    const colors = [];
    const uvs = [];
    const starts = [];

    let instructions = {};

    if (trace_id in traces) {
        instructions = traces[trace_id].raw;
    }

    let y = 0;

    for (let i = 0; i < instructions.length; ++i) {
        const instruction = instructions[i];
        result.count += pack_instruction(instruction, positions, sizes, colors, uvs, starts, y);
        if (config.limit > 0 && result.count >= config.limit) {
            break;
        }
        ++y;
    }

    starts.push(positions.length);

    if (false) {
        result.pos = new Float32Array([0, 0]);
        result.size = new Float32Array([config.raster_texture_size, config.raster_texture_size]);
        result.color = new Uint8Array([0, 0, 0, 255]);
        result.uv = new Float32Array([0, 0]);
        result.count = 1;
        result.trace_id = trace_id;
        result.uploaded = false;
    } else {
        result.pos = new Float32Array(positions);
        result.size = new Float32Array(sizes);
        result.color = new Uint8Array(colors);
        result.uv = new Float32Array(uvs);
        result.trace_id = trace_id;
        result.uploaded = false;
        result.start = new Int32Array(starts);
    }

    const after = performance.now();

    console.log(`Generated geometry in ${Math.round(after - before)}ms`);

    return result;
}

function clip(quads) {
    const tl = screen_to_canvas({'x': 0, 'y': 0});
    const br = screen_to_canvas({'x': 0, 'y': canvas.height});

    const x1 = tl.x;
    const y1 = tl.y;

    const x2 = br.x;
    const y2 = br.y;

    const result = {
        'count': 0,
    };

    if (quads.count === 0) {
        return result;
    }

    let i0 = -1;
    let i1 = -1;

    for (let i = 0; i < quads.start.length - 1; ++i) {
        const index = quads.start[i];
        const next = quads.start[i + 1];

        const left = quads.pos[index];
        const top = quads.pos[index + 1];
        const bottom = top + quads.size[index + 1];
        const right = quads.pos[next - 2] + quads.size[next - 2];

        if (bottom < y1) {
            if (i < quads.start.length / 2 - 2) {
                const index_ahead = quads.start[i * 2];
                const top_ahead = quads.pos[index_ahead + 1];
                const bottom_ahead = top_ahead + quads.size[index_ahead + 1];

                if (bottom_ahead < y1) {
                    i *= 2;
                    continue;
                }
            }
        }

        if (bottom < y1 || right < x1) {
            continue;
        }

        if (top > y2) {
            i1 = quads.start[i + 1];
            break;
        }

        if (i0 === -1) {
            i0 = index;
        }
    }

    result.pos = quads.pos.subarray(i0, i1);
    result.size = quads.size.subarray(i0, i1);
    result.color = quads.color.subarray(i0 * 2, i1 * 2);
    result.uv = quads.uv.subarray(i0, i1);
    result.count = (i1 - i0) / 2;
    result.uploaded = false;

    return result;
}