from __future__ import annotations

import html
import math
from pathlib import Path
from typing import Any

from PIL import Image, ImageDraw, ImageFont

from .verifier import (
    make_container_shape,
    make_item_shape,
    normalize_solution,
    solution_case,
)


GREEN = (205, 247, 214)
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)


def font(size: int, bold: bool = False, scale: int = 1) -> ImageFont.ImageFont:
    names = [
        "/System/Library/Fonts/Supplemental/Arial Bold.ttf" if bold else "/System/Library/Fonts/Supplemental/Arial.ttf",
        "/System/Library/Fonts/Supplemental/Helvetica Bold.ttf" if bold else "/System/Library/Fonts/Supplemental/Helvetica.ttf",
        "/Library/Fonts/Arial Bold.ttf" if bold else "/Library/Fonts/Arial.ttf",
        "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf" if bold else "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf",
    ]
    for name in names:
        if Path(name).exists():
            return ImageFont.truetype(name, size=size * scale)
    return ImageFont.load_default()


def all_points(container: dict[str, Any], shapes: list[dict[str, Any]]) -> list[tuple[float, float]]:
    points: list[tuple[float, float]] = []
    if container["kind"] == "circle":
        cx, cy = container["center"]
        r = container["radius"]
        points.extend([(cx - r, cy - r), (cx + r, cy + r)])
    else:
        points.extend(container["vertices"])
    for shape in shapes:
        if shape["kind"] == "circle":
            cx, cy = shape["center"]
            r = shape["radius"]
            points.extend([(cx - r, cy - r), (cx + r, cy + r)])
        else:
            points.extend(shape["vertices"])
    return points


def transform_factory(
    points: list[tuple[float, float]],
    size: int,
    label_height: int,
    margin: int,
    supersample: int,
):
    xs = [x for x, _ in points]
    ys = [y for _, y in points]
    minx, maxx = min(xs), max(xs)
    miny, maxy = min(ys), max(ys)
    width = max(maxx - minx, 1.0e-12)
    height = max(maxy - miny, 1.0e-12)
    left, top = margin, label_height
    right, bottom = size - margin, size - margin
    scale = min((right - left) / width, (bottom - top) / height)
    offx = left + ((right - left) - width * scale) * 0.5
    offy = top + ((bottom - top) - height * scale) * 0.5

    def xy(point: tuple[float, float]) -> tuple[int, int]:
        x, y = point
        px = offx + (x - minx) * scale
        py = offy + (maxy - y) * scale
        return round(px * supersample), round(py * supersample)

    def length(value: float) -> int:
        return round(value * scale * supersample)

    return xy, length


def draw_closed(draw: ImageDraw.ImageDraw, points: list[tuple[int, int]], width: int) -> None:
    draw.line(points + [points[0]], fill=BLACK, width=width, joint="curve")


def render_png(solution: dict[str, Any], path: Path, size: int = 900, label: bool = True) -> Path:
    solution = normalize_solution(solution)
    container = make_container_shape(solution["container"])
    shapes = [make_item_shape(solution["item"], placement) for placement in solution["placements"]]
    ss = 3
    label_height = 82 if label else 28
    xy, lens = transform_factory(all_points(container, shapes), size, label_height, 30, ss)

    img = Image.new("RGB", (size * ss, size * ss), WHITE)
    draw = ImageDraw.Draw(img)
    if label:
        title_font = font(30, bold=True, scale=ss)
        side_font = font(28, bold=True, scale=ss)
        case = solution_case(solution)
        side = make_container_shape(solution["container"])["side"]
        side_label = f"s={side:.5f}"
        draw.text((24 * ss, 18 * ss), case, fill=BLACK, font=title_font)
        bbox = draw.textbbox((0, 0), side_label, font=side_font)
        draw.text(((size - 24) * ss - (bbox[2] - bbox[0]), 20 * ss), side_label, fill=BLACK, font=side_font)

    for shape in shapes:
        if shape["kind"] == "circle":
            cx, cy = xy(shape["center"])
            r = lens(shape["radius"])
            draw.ellipse((cx - r, cy - r, cx + r, cy + r), fill=GREEN, outline=BLACK, width=3 * ss)
        else:
            pts = [xy(point) for point in shape["vertices"]]
            draw.polygon(pts, fill=GREEN)
            draw_closed(draw, pts, width=3 * ss)

    if container["kind"] == "circle":
        cx, cy = xy(container["center"])
        r = lens(container["radius"])
        draw.ellipse((cx - r, cy - r, cx + r, cy + r), outline=BLACK, width=6 * ss)
    else:
        draw_closed(draw, [xy(point) for point in container["vertices"]], width=6 * ss)

    img = img.resize((size, size), Image.Resampling.LANCZOS)
    path.parent.mkdir(parents=True, exist_ok=True)
    img.save(path, optimize=True)
    return path


def svg_markup(solution: dict[str, Any], size: int = 900) -> str:
    solution = normalize_solution(solution)
    container = make_container_shape(solution["container"])
    shapes = [make_item_shape(solution["item"], placement) for placement in solution["placements"]]
    points = all_points(container, shapes)
    xs = [x for x, _ in points]
    ys = [y for _, y in points]
    minx, maxx = min(xs), max(xs)
    miny, maxy = min(ys), max(ys)
    pad = max(maxx - minx, maxy - miny) * 0.05 + 1.0e-9
    view = f"{minx - pad:.12g} {-maxy - pad:.12g} {maxx - minx + 2 * pad:.12g} {maxy - miny + 2 * pad:.12g}"
    stroke = max(maxx - minx, maxy - miny) / 260.0

    def pts(poly: list[tuple[float, float]]) -> str:
        return " ".join(f"{x:.12g},{-y:.12g}" for x, y in poly)

    body = [
        f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="{view}" width="{size}" height="{size}">',
        f"  <title>{html.escape(solution_case(solution))}</title>",
        '  <g stroke="black" stroke-linejoin="round">',
    ]
    for shape in shapes:
        if shape["kind"] == "circle":
            cx, cy = shape["center"]
            body.append(
                f'    <circle cx="{cx:.12g}" cy="{-cy:.12g}" r="{shape["radius"]:.12g}" fill="#cdf7d6" stroke-width="{stroke:.12g}"/>'
            )
        else:
            body.append(f'    <polygon points="{pts(shape["vertices"])}" fill="#cdf7d6" stroke-width="{stroke:.12g}"/>')
    if container["kind"] == "circle":
        cx, cy = container["center"]
        body.append(
            f'    <circle cx="{cx:.12g}" cy="{-cy:.12g}" r="{container["radius"]:.12g}" fill="none" stroke-width="{2.6 * stroke:.12g}"/>'
        )
    else:
        body.append(f'    <polygon points="{pts(container["vertices"])}" fill="none" stroke-width="{2.6 * stroke:.12g}"/>')
    body.extend(["  </g>", "</svg>"])
    return "\n".join(body) + "\n"