#!/usr/bin/env python3
"""Convert ObservableObject/@Published Swift files to imperative onChange pattern."""
import re
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1] / "suixinkan_ios"

def convert_file(path: Path) -> bool:
    text = path.read_text(encoding="utf-8")
    original = text

    if "ObservableObject" not in text and "@Published" not in text and "import Combine" not in text:
        return False

    text = re.sub(r"^import Combine\n", "", text, flags=re.MULTILINE)

    if ": ObservableObject" in text:
        text = text.replace(": ObservableObject", "")
        # Insert onChange after class opening brace
        def add_onchange(match):
            decl = match.group(0)
            if "onChange:" in text[match.end():match.end()+200]:
                return decl
            return decl + "\n    var onChange: (() -> Void)?\n"
        text = re.sub(
            r"(final class \w+[^{]*\{)\n",
            add_onchange,
            text,
            count=1,
        )

    def repl_published(m):
        access = m.group(1) or ""
        name = m.group(2)
        rest = m.group(3)
        return f"{access}var {name}{rest} {{ didSet {{ onChange?() }} }}\n"

    text = re.sub(
        r"@Published\s+(private\(set\)\s+)?var\s+(\w+)([^=\n]*=\s*[^\n]+)\n",
        repl_published,
        text,
    )
    text = re.sub(
        r"@Published\s+(private\(set\)\s+)?var\s+(\w+)([^=\n]*)\n",
        lambda m: f"{m.group(1) or ''}var {m.group(2)}{m.group(3)} {{ didSet {{ onChange?() }} }}\n",
        text,
    )

    if text != original:
        path.write_text(text, encoding="utf-8")
        return True
    return False

def main():
    changed = 0
    for path in ROOT.rglob("*.swift"):
        if convert_file(path):
            changed += 1
            print(f"converted: {path.relative_to(ROOT.parent)}")
    print(f"Done. {changed} files converted.")

if __name__ == "__main__":
    main()