#!/usr/bin/env python3
"""
Zephyr build helper for app_i_core_link.

Usage:
  python zbuild.py dr2501a_g070rb
  python zbuild.py dr2501a_g070rb -p auto
  python zbuild.py -p always                         (auto-detect board from west.yml)
  python zbuild.py dr2501a_g070rb -T sample.helloworld

Options:
  board       Board name (optional, auto-detected from west.yml if omitted)
  -p PURSE    Pristine option: auto / always / never
  -t TARGET   CMake target to run after build, e.g. test / flash
  -T TEST     Test name/sample identifier (e.g. sample.helloworld)

Steps:
  1. west topdir → find Zephyr workspace root
  2. west config --local manifest.file <this_script_dir>/west.yml
  3. west build [-p PURSE] -b BOARD [-t TARGET] [-T TEST] <this_script_dir>
"""

import argparse
import os
import re
import subprocess
import sys


def get_script_dir() -> str:
    """Absolute path to the directory containing this script."""
    return os.path.dirname(os.path.abspath(__file__))


def run(cmd: list[str], cwd: str | None = None) -> str:
    """Run a command and return stdout.  Exit on failure."""
    proc = subprocess.run(cmd, capture_output=True, text=True, cwd=cwd)
    if proc.returncode != 0:
        print(f"  ✗ {' '.join(cmd)}", file=sys.stderr)
        print(f"    {proc.stderr.strip()}", file=sys.stderr)
        sys.exit(proc.returncode)
    return proc.stdout.strip()


def discover_boards(manifest_path: str) -> list[str]:
    """Parse west.yml and return board names whose path starts with 'boards/'."""
    if not os.path.exists(manifest_path):
        return []

    with open(manifest_path) as f:
        content = f.read()

    # Match entries like:
    #   - name: <board_name>
    #     path: boards/<something>
    boards = re.findall(r"name:\s*(\S+)\s*\n\s+path:\s*boards/\S+", content)
    return boards


def main():
    parser = argparse.ArgumentParser(
        description="Zephyr build helper for app_i_core_link"
    )
    parser.add_argument(
        "board",
        nargs="?",
        default=None,
        help="Board name (optional, auto-detected from west.yml if omitted)",
    )
    parser.add_argument(
        "-p",
        "--pristine",
        default=None,
        choices=["auto", "always", "never"],
        help="Pristine build option",
    )
    parser.add_argument(
        "-t",
        "--target",
        default=None,
        help="CMake target to run after build (e.g. test, flash)",
    )
    parser.add_argument(
        "-T",
        "--test",
        default=None,
        dest="test_id",
        help="Test name / sample identifier (e.g. sample.helloworld)",
    )
    parser.add_argument(
        "--update",
        action="store_true",
        help="Run west update after setting manifest",
    )
    args = parser.parse_args()

    # ── 0. Auto-detect board from west.yml when not specified ───
    if args.board is None:
        script_dir = get_script_dir()
        manifest = os.path.join(script_dir, "west.yml")
        boards = discover_boards(manifest)

        if len(boards) == 0:
            print(
                "  ✗ No board specified and no board found in west.yml "
                "(no entry with path: boards/...)",
                file=sys.stderr,
            )
            sys.exit(1)
        elif len(boards) == 1:
            args.board = boards[0]
            print(f"  → Auto-detected board: {args.board}")
        else:
            print(
                "  ✗ No board specified. Multiple boards found in west.yml:",
                ", ".join(boards),
                "\n    Please specify one explicitly.",
                file=sys.stderr,
            )
            sys.exit(1)

    script_dir = get_script_dir()
    manifest = os.path.join(script_dir, "west.yml")

    print(f"  script dir  : {script_dir}")
    print(f"  board       : {args.board}")
    print(f"  pristine    : {args.pristine or '(none)'}")
    print(f"  target      : {args.target or '(none)'}")
    print(f"  test        : {args.test_id or '(none)'}")
    print(f"  update      : {'yes' if args.update else 'no'}")

    # ── 1. Find workspace root ───────────────────────────────
    print("\n  [1/3] Finding west workspace root...")
    topdir = run(["west", "topdir"])
    print(f"    → {topdir}")

    # ── 2. Set local manifest ────────────────────────────────
    print("\n  [2/3] Setting local manifest...")
    if not os.path.exists(manifest):
        print(f"    ✗ manifest not found: {manifest}", file=sys.stderr)
        sys.exit(1)
    run(["west", "config", "--local", "manifest.file", manifest], cwd=topdir)
    print(f"    → manifest.file = {manifest}")

    # ── 2.5. Run west update (optional) ───────────────────────
    if args.update:
        print("\n  [2.5/3] Running west update...")
        run(["west", "update", "--fetch", "smart"], cwd=topdir)
        print("    → update done")

    # ── 3. Run west build ─────────────────────────────────────
    print("\n  [3/3] Running west build...")
    build_cmd = ["west", "build"]
    if args.pristine:
        build_cmd += ["-p", args.pristine]
    build_cmd += ["-b", args.board]
    if args.target:
        build_cmd += ["-t", args.target]
    if args.test_id:
        build_cmd += ["-T", args.test_id]
    build_cmd += [script_dir]

    print(f"    $ {' '.join(build_cmd)}")
    proc = subprocess.run(build_cmd, cwd=topdir)
    if proc.returncode != 0:
        print(f"\n  ✗ Build failed (exit code {proc.returncode})")
        sys.exit(proc.returncode)
    print("\n  ✓ Build succeeded")


if __name__ == "__main__":
    main()