#!/usr/bin/env python3
import argparse, os, sys, subprocess, yaml
from llm_clients import LLMClient
from prompt_inject import render_template
from chunker import chunk_text

def read(path):
    with open(path, "r", encoding="utf-8") as f:
        return f.read()

def write(path, content):
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "w", encoding="utf-8") as f:
        f.write(content)

def load_cfg():
    cfg_path = "porting/CONFIG.yml"
    if not os.path.exists(cfg_path):
        cfg_path = "porting/CONFIG.example.yml"
    with open(cfg_path, "r", encoding="utf-8") as f:
        return yaml.safe_load(f)

def main():
    p = argparse.ArgumentParser()
    p.add_argument("--mode", required=True, choices=["header-to-traits", "impl-pass", "unit-tests", "review-fixit"])
    p.add_argument("--input", required=True, help="Path to C++ source (or error log for review-fixit)")
    p.add_argument("--skeleton", default=None, help="Existing Rust module to guide/patch")
    p.add_argument("--out", required=True, help="Output Rust file (or tests module for unit-tests)")
    p.add_argument("--test-spec", default=None, help="Text spec or path to spec")
    args = p.parse_args()

    cfg = load_cfg()
    client = LLMClient(cfg, cfg["logs"]["dir"])

    glossary = read(cfg["project"]["glossary_path"])
    style = read(cfg["project"]["style_path"])
    determinism = read(cfg["project"]["determinism_path"])

    def load_prompt(name):
        return read(cfg["prompts"][name])

    system = ""
    if args.mode == "header-to-traits":
        tmpl = load_prompt("header_to_traits")
        src = read(args.input)
        skel = read(args.skeleton) if args.skeleton and os.path.exists(args.skeleton) else ""
        user = render_template(
            tmpl,
            GLOSSARY=glossary,
            STYLE=style,
            DETERMINISM=determinism,
            SKELETON=skel,
            SOURCE_CHUNK=src,
        )
        resp = client.chat(system, user)
        write(args.out, resp)

    elif args.mode == "impl-pass":
        tmpl = load_prompt("impl_pass")
        src = read(args.input)
        skel = read(args.skeleton) if args.skeleton and os.path.exists(args.skeleton) else ""
        test_spec = read(args.test_spec) if args.test_spec and os.path.exists(args.test_spec) else (args.test_spec or "")
        user = render_template(
            tmpl,
            GLOSSARY=glossary,
            STYLE=style,
            DETERMINISM=determinism,
            SKELETON=skel,
            SOURCE_CHUNK=src,
            TEST_SPEC=test_spec,
        )
        resp = client.chat(system, user)
        write(args.out, resp)

    elif args.mode == "unit-tests":
        tmpl = load_prompt("unit_tests")
        skel = read(args.skeleton) if args.skeleton and os.path.exists(args.skeleton) else ""
        test_spec = read(args.test_spec) if args.test_spec and os.path.exists(args.test_spec) else (args.test_spec or "")
        user = render_template(
            tmpl,
            DETERMINISM=determinism,
            SKELETON=skel,
            TEST_SPEC=test_spec,
        )
        resp = client.chat(system, user)
        # Append or create tests in the same file:
        if os.path.exists(args.out):
            write(args.out, read(args.out) + "\n\n" + resp)
        else:
            write(args.out, resp)

    elif args.mode == "review-fixit":
        tmpl = load_prompt("review_fixit")
        errors = read(args.input)
        skel = read(args.skeleton) if args.skeleton and os.path.exists(args.skeleton) else ""
        user = render_template(
            tmpl,
            STYLE=style,
            DETERMINISM=determinism,
            SNIPPET=skel,
            ERRORS=errors,
        )
        resp = client.chat(system, user)
        write(args.out, resp)

    else:
        print(f"Unknown mode: {args.mode}", file=sys.stderr)
        sys.exit(2)

    # Compile after generation if configured
    bcmd = cfg["compile"].get("build_cmd")
    if bcmd:
        subprocess.run(bcmd, shell=True)

if __name__ == "__main__":
    main()