import csv
import os
import math

IMG_SIZE = 512

SHAPES = {
    "circle":               ("circle",                    "diameter"),
    "square":               ("axis-aligned square",      "side length"),
    "equilateral triangle": ("upright equilateral triangle", "side length"),
}

SIZE_RATIOS = [0.2, 0.4, 0.6, 0.8, 1.0]

# POSITIONS_DEFAULT = {
#     "left":   "aligned with the left edge, vertically centered",
#     "top":    "aligned with the top edge, horizontally centered",
#     "right":  "aligned with the right edge, vertically centered",
#     "bottom": "aligned with the bottom edge, horizontally centered",
#     "center": "centered in the image",
# }
POSITIONS_DEFAULT = {
    "left":   "with its bounding box aligned with the left edge, vertically centered",
    "top":    "with its bounding box aligned with the top edge, horizontally centered",
    "right":  "with its bounding box aligned with the right edge, vertically centered",
    "bottom": "with its bounding box aligned with the bottom edge, horizontally centered",
    "center": "with its bounding box centered in the image",
}

POSITIONS_TRIANGLE = {
    "left":   "with its bounding box aligned with the left edge, vertically centered",
    "top":    "with its bounding box aligned with the top edge, horizontally centered",
    "right":  "with its bounding box aligned with the right edge, vertically centered",
    "bottom": "with its bounding box aligned with the bottom edge, horizontally centered",
    "center": "with its bounding box centered in the image",
}


def get_bounding_half(shape, size_ratio):
    """Return (half_w, half_h) of the shape's bounding box."""
    side = size_ratio * IMG_SIZE
    if shape == "circle":
        r = side / 2
        return r, r
    elif shape == "square":
        return side / 2, side / 2
    elif shape == "equilateral triangle":
        h = side * math.sqrt(3) / 2
        return side / 2, h / 2


def get_center(position, half_w, half_h):
    """Return (cx, cy) for the given position."""
    mid = IMG_SIZE / 2
    if position == "left":
        return half_w, mid
    elif position == "top":
        return mid, half_h
    elif position == "right":
        return IMG_SIZE - half_w, mid
    elif position == "bottom":
        return mid, IMG_SIZE - half_h
    elif position == "center":
        return mid, mid


def is_out_of_bounds(cx, cy, half_w, half_h):
    return (cx - half_w < 0 or cx + half_w > IMG_SIZE or
            cy - half_h < 0 or cy + half_h > IMG_SIZE)


def generate_metadata(prompt_file, output_file):
    with open(prompt_file, "r", encoding="utf-8") as f:
        prompts = list(csv.DictReader(f))

    rows = []
    id_counter = 1
    skipped = 0

    for prompt in prompts:
        prompt_text = prompt["prompt"]
        for shape_key, (shape_desc, size_desc) in SHAPES.items():
            for size_ratio in SIZE_RATIOS:
                half_w, half_h = get_bounding_half(shape_key, size_ratio)
                for pos_key in POSITIONS_DEFAULT:
                    pos_desc = (POSITIONS_TRIANGLE if shape_key == "equilateral triangle" else POSITIONS_DEFAULT)[pos_key]
                    cx, cy = get_center(pos_key, half_w, half_h)
                    if is_out_of_bounds(cx, cy, half_w, half_h):
                        skipped += 1
                        continue

                    filled = (prompt_text
                              .replace("<shape>", shape_desc)
                              .replace("<size_desc>", size_desc)
                              .replace("<size>", f"{int(size_ratio * 100)}%")
                              .replace("<position>", pos_desc))

                    rows.append({
                        "id": id_counter,
                        "prompt": filled,
                        "shape": shape_key,
                        "position": pos_key,
                        "size_ratio": size_ratio,
                        "center_x": round(cx),
                        "center_y": round(cy),
                        "task": 3,
                    })
                    id_counter += 1

    output_dir = os.path.dirname(output_file)
    if output_dir and not os.path.exists(output_dir):
        os.makedirs(output_dir, exist_ok=True)

    with open(output_file, "w", newline="", encoding="utf-8") as f:
        writer = csv.DictWriter(f, fieldnames=["id", "prompt", "shape", "position", "size_ratio", "center_x", "center_y", "task"])
        writer.writeheader()
        writer.writerows(rows)

    print(f"Generation complete: {output_file} ({len(rows)} rows, {skipped} skipped as out-of-bounds)")


generate_metadata("raw_config/Task_Geometric.csv", "metadata/Task_Geometric_metadata.csv")