from __future__ import annotations

from pathlib import Path

from PIL import Image, ImageDraw

from driftwm.utils import ensure_dir


OUT_DIR = Path("experiments/reports/figures/task_schematics")
WORKSPACE = (0.0, 10.0, 0.0, 10.0)

BG = (247, 250, 252)
BORDER = (45, 62, 80)
START = (35, 91, 140)
GOAL = (203, 62, 74)
ACTIVE = (30, 139, 88)
PASSIVE = (145, 153, 163)
FLOW = (68, 135, 205)
SWITCH = (238, 184, 72)


def w2p(x: float, y: float, size: int = 640, pad: int = 58) -> tuple[int, int]:
    xmin, xmax, ymin, ymax = WORKSPACE
    px = int(pad + (x - xmin) / (xmax - xmin) * (size - 2 * pad))
    py = int(size - pad - (y - ymin) / (ymax - ymin) * (size - 2 * pad))
    return px, py


def draw_arrow(
    draw: ImageDraw.ImageDraw,
    p0: tuple[int, int],
    p1: tuple[int, int],
    color: tuple[int, int, int],
    width: int = 6,
    head: int = 18,
) -> None:
    import math

    draw.line((p0, p1), fill=color, width=width)
    dx = p1[0] - p0[0]
    dy = p1[1] - p0[1]
    angle = math.atan2(dy, dx)
    for delta in (2.55, -2.55):
        a = angle + delta
        q = (int(p1[0] + head * math.cos(a)), int(p1[1] + head * math.sin(a)))
        draw.line((p1, q), fill=color, width=width)


def draw_polyline_arrow(
    draw: ImageDraw.ImageDraw,
    pts: list[tuple[int, int]],
    color: tuple[int, int, int],
    width: int = 6,
) -> None:
    if len(pts) < 2:
        return
    draw.line(pts, fill=color, width=width, joint="curve")
    draw_arrow(draw, pts[-2], pts[-1], color, width=width)


def circle(draw: ImageDraw.ImageDraw, center: tuple[int, int], radius: int, color: tuple[int, int, int], width: int = 0) -> None:
    box = (center[0] - radius, center[1] - radius, center[0] + radius, center[1] + radius)
    if width:
        draw.ellipse(box, outline=color, width=width)
    else:
        draw.ellipse(box, fill=color)


def base(size: int = 640) -> tuple[Image.Image, ImageDraw.ImageDraw]:
    img = Image.new("RGB", (size, size), BG)
    draw = ImageDraw.Draw(img)
    draw.rectangle((58, 58, size - 58, size - 58), outline=BORDER, width=3)
    return img, draw


def draw_flow_arrows(draw: ImageDraw.ImageDraw, arrows: list[tuple[tuple[float, float], tuple[float, float]]]) -> None:
    for start, end in arrows:
        draw_arrow(draw, w2p(*start), w2p(*end), FLOW, width=5, head=15)


def save(img: Image.Image, name: str) -> None:
    ensure_dir(OUT_DIR / "clean")
    path = OUT_DIR / "clean" / name
    img.save(path)
    print(path)


def reach_target() -> Image.Image:
    img, draw = base()
    start = w2p(2.0, 2.0)
    goal = w2p(8.0, 8.0)
    draw_arrow(draw, start, goal, ACTIVE)
    circle(draw, start, 13, START)
    circle(draw, goal, 18, GOAL, width=6)
    return img


def station_keeping() -> Image.Image:
    img, draw = base()
    center = w2p(5.0, 5.0)
    circle(draw, center, 72, GOAL, width=6)
    draw.line((center[0] - 22, center[1], center[0] + 22, center[1]), fill=GOAL, width=4)
    draw.line((center[0], center[1] - 22, center[0], center[1] + 22), fill=GOAL, width=4)
    draw_flow_arrows(draw, [((6.8, 6.8), (5.85, 5.95)), ((6.6, 3.3), (5.8, 4.2)), ((3.5, 6.8), (4.25, 5.9))])
    pts = [w2p(4.55, 4.25), w2p(5.2, 4.45), w2p(5.45, 5.15), w2p(4.85, 5.45), w2p(4.65, 4.8), w2p(5.0, 5.02)]
    draw_polyline_arrow(draw, pts, ACTIVE, width=6)
    circle(draw, pts[0], 12, START)
    return img


def waypoint_square() -> Image.Image:
    img, draw = base()
    start = w2p(2.0, 2.0)
    pts = [w2p(2.5, 2.5), w2p(7.5, 2.5), w2p(7.5, 7.5), w2p(2.5, 7.5)]
    draw_polyline_arrow(draw, [start] + pts, ACTIVE, width=6)
    circle(draw, start, 13, START)
    for p in pts:
        circle(draw, p, 13, GOAL)
    return img


def waypoint_zigzag() -> Image.Image:
    img, draw = base()
    start = w2p(2.0, 2.0)
    pts = [w2p(2.5, 7.0), w2p(4.2, 3.0), w2p(5.8, 7.0), w2p(7.5, 3.0)]
    draw_polyline_arrow(draw, [start] + pts, ACTIVE, width=6)
    circle(draw, start, 13, START)
    for p in pts:
        circle(draw, p, 13, GOAL)
    return img


def make_contact_sheet(names: list[str]) -> None:
    ensure_dir(OUT_DIR)
    thumbs = [Image.open(OUT_DIR / "clean" / name).resize((240, 240), Image.Resampling.LANCZOS) for name in names]
    sheet = Image.new("RGB", (2 * 280 + 40, 2 * 300 + 40), (246, 249, 251))
    draw = ImageDraw.Draw(sheet)
    labels = [name.removeprefix("task_").removesuffix(".png") for name in names]
    for i, (thumb, label) in enumerate(zip(thumbs, labels, strict=True)):
        row, col = divmod(i, 2)
        x = 20 + col * 280
        y = 20 + row * 300
        sheet.paste(thumb, (x, y))
        draw.text((x, y + 250), label, fill=(35, 45, 58))
    path = OUT_DIR / "task_schematics_contact_sheet.png"
    sheet.save(path)
    print(path)


def main() -> None:
    tasks = {
        "task_reach_target.png": reach_target(),
        "task_station_keeping.png": station_keeping(),
        "task_waypoint_square.png": waypoint_square(),
        "task_waypoint_zigzag.png": waypoint_zigzag(),
    }
    for name, img in tasks.items():
        save(img, name)
    make_contact_sheet(
        [
            "task_reach_target.png",
            "task_station_keeping.png",
            "task_waypoint_square.png",
            "task_waypoint_zigzag.png",
        ]
    )


if __name__ == "__main__":
    main()