import csv
import os
from PIL import Image

def normalize_hex(hex_color: str) -> str:
    """Make sure the hex color starts with #"""
    if not hex_color:
        return "#000000"
    hex_color = hex_color.strip()
    return hex_color if hex_color.startswith("#") else f"#{hex_color}"

def replace_placeholders(prompt: str, row: dict) -> str:
    """Replace the placeholder in prompt"""
    color_format = row.get("color_format", "").strip() or "Hex code"
    mapping = {
        "<color_format>": color_format,
        "<color_1>": normalize_hex(row.get("color_1", "")),
        "<color_2>": normalize_hex(row.get("color_2", "")),
    }
    out = prompt
    for k, v in mapping.items():
        if k in out and v:
            out = out.replace(k, v)
    return out

def generate_two_color_images_with_split(csv_file, base_dir, size=(256, 256)):
    with open(csv_file, "r", encoding="utf-8") as f:
        reader = csv.DictReader(f)
        rows = list(reader)

    for row in rows:
        id_val = row["id"].strip()
        hex1 = normalize_hex(row.get("color_1", ""))
        hex2 = normalize_hex(row.get("color_2", ""))
        prompt_raw = row.get("prompt", "").strip()
        split = (row.get("split") or "train").strip()
        direction = row.get("direction", "").strip()

        # Replace the placeholder in prompt
        prompt_filled = replace_placeholders(prompt_raw, row)

        
        # out_dir = os.path.join(base_dir, split)
        out_dir = base_dir
        os.makedirs(out_dir, exist_ok=True)

        # file path
        img_path = os.path.join(out_dir, f"id_{id_val}.png")
        txt_path = os.path.join(out_dir, f"id_{id_val}.txt")

        # Create a blank drawing
        img = Image.new("RGB", size)

        # direction
        if direction=="h":  # horizontal   Top and bottom split
            top = Image.new("RGB", (size[0], size[1] // 2), hex1)
            bottom = Image.new("RGB", (size[0], size[1] // 2), hex2)
            img.paste(top, (0, 0))
            img.paste(bottom, (0, size[1] // 2))
        elif direction=="v":  # vertical  Left and right split
            left = Image.new("RGB", (size[0] // 2, size[1]), hex1)
            right = Image.new("RGB", (size[0] // 2, size[1]), hex2)
            img.paste(left, (0, 0))
            img.paste(right, (size[0] // 2, 0))
        else:
            img = Image.new("RGB", size, hex1)

        img.save(img_path)

        # write prompt
        with open(txt_path, "w", encoding="utf-8") as f:
            f.write(prompt_filled)

        print(f"Generate: {img_path}, {txt_path} (split={split}, colors={hex1},{hex2})")


generate_two_color_images_with_split(
    "metadata/Variation_2_Color_1.csv",
    base_dir="data/Variation_2/Color_Level_1"
)
generate_two_color_images_with_split(
    "metadata/Variation_2_Color_2.csv",
    base_dir="data/Variation_2/Color_Level_2"
)
generate_two_color_images_with_split(
    "metadata/Variation_2_Color_3.csv",
    base_dir="data/Variation_2/Color_Level_3"
)