#!/usr/bin/env python3
"""Install LLMX native binaries (Rust CLI plus ripgrep helpers)."""

import argparse
import json
import os
import shutil
import subprocess
import tarfile
import tempfile
import zipfile
from dataclasses import dataclass
from concurrent.futures import ThreadPoolExecutor, as_completed
from pathlib import Path
from typing import Iterable, Sequence
from urllib.parse import urlparse
from urllib.request import urlopen

SCRIPT_DIR = Path(__file__).resolve().parent
LLMX_CLI_ROOT = SCRIPT_DIR.parent
DEFAULT_WORKFLOW_URL = "https://github.com/valknar/llmx/actions/runs/17952349351"  # rust-v0.40.0
VENDOR_DIR_NAME = "vendor"
RG_MANIFEST = LLMX_CLI_ROOT / "bin" / "rg"
BINARY_TARGETS = (
    "x86_64-unknown-linux-musl",
    "aarch64-unknown-linux-musl",
    "x86_64-apple-darwin",
    "aarch64-apple-darwin",
    "x86_64-pc-windows-msvc",
    "aarch64-pc-windows-msvc",
)


@dataclass(frozen=True)
class BinaryComponent:
    artifact_prefix: str  # matches the artifact filename prefix (e.g. codex-<target>.zst)
    dest_dir: str  # directory under vendor/<target>/ where the binary is installed
    binary_basename: str  # executable name inside dest_dir (before optional .exe)


BINARY_COMPONENTS = {
    "llmx": BinaryComponent(
        artifact_prefix="llmx",
        dest_dir="llmx",
        binary_basename="llmx",
    ),
    "llmx-responses-api-proxy": BinaryComponent(
        artifact_prefix="llmx-responses-api-proxy",
        dest_dir="llmx-responses-api-proxy",
        binary_basename="llmx-responses-api-proxy",
    ),
}

RG_TARGET_PLATFORM_PAIRS: list[tuple[str, str]] = [
    ("x86_64-unknown-linux-musl", "linux-x86_64"),
    ("aarch64-unknown-linux-musl", "linux-aarch64"),
    ("x86_64-apple-darwin", "macos-x86_64"),
    ("aarch64-apple-darwin", "macos-aarch64"),
    ("x86_64-pc-windows-msvc", "windows-x86_64"),
    ("aarch64-pc-windows-msvc", "windows-aarch64"),
]
RG_TARGET_TO_PLATFORM = {target: platform for target, platform in RG_TARGET_PLATFORM_PAIRS}
DEFAULT_RG_TARGETS = [target for target, _ in RG_TARGET_PLATFORM_PAIRS]


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Install native LLMX binaries.")
    parser.add_argument(
        "--workflow-url",
        help=(
            "GitHub Actions workflow URL that produced the artifacts. Defaults to a "
            "known good run when omitted."
        ),
    )
    parser.add_argument(
        "--component",
        dest="components",
        action="append",
        choices=tuple(list(BINARY_COMPONENTS) + ["rg"]),
        help=(
            "Limit installation to the specified components."
            " May be repeated. Defaults to 'codex' and 'rg'."
        ),
    )
    parser.add_argument(
        "root",
        nargs="?",
        type=Path,
        help=(
            "Directory containing package.json for the staged package. If omitted, the "
            "repository checkout is used."
        ),
    )
    return parser.parse_args()


def main() -> int:
    args = parse_args()

    codex_cli_root = (args.root or LLMX_CLI_ROOT).resolve()
    vendor_dir = codex_cli_root / VENDOR_DIR_NAME
    vendor_dir.mkdir(parents=True, exist_ok=True)

    components = args.components or ["llmx", "rg"]

    workflow_url = (args.workflow_url or DEFAULT_WORKFLOW_URL).strip()
    if not workflow_url:
        workflow_url = DEFAULT_WORKFLOW_URL

    workflow_id = workflow_url.rstrip("/").split("/")[-1]
    print(f"Downloading native artifacts from workflow {workflow_id}...")

    with tempfile.TemporaryDirectory(prefix="llmx-native-artifacts-") as artifacts_dir_str:
        artifacts_dir = Path(artifacts_dir_str)
        _download_artifacts(workflow_id, artifacts_dir)
        install_binary_components(
            artifacts_dir,
            vendor_dir,
            BINARY_TARGETS,
            [name for name in components if name in BINARY_COMPONENTS],
        )

    if "rg" in components:
        print("Fetching ripgrep binaries...")
        fetch_rg(vendor_dir, DEFAULT_RG_TARGETS, manifest_path=RG_MANIFEST)

    print(f"Installed native dependencies into {vendor_dir}")
    return 0


def fetch_rg(
    vendor_dir: Path,
    targets: Sequence[str] | None = None,
    *,
    manifest_path: Path,
) -> list[Path]:
    """Download ripgrep binaries described by the DotSlash manifest."""

    if targets is None:
        targets = DEFAULT_RG_TARGETS

    if not manifest_path.exists():
        raise FileNotFoundError(f"DotSlash manifest not found: {manifest_path}")

    manifest = _load_manifest(manifest_path)
    platforms = manifest.get("platforms", {})

    vendor_dir.mkdir(parents=True, exist_ok=True)

    targets = list(targets)
    if not targets:
        return []

    task_configs: list[tuple[str, str, dict]] = []
    for target in targets:
        platform_key = RG_TARGET_TO_PLATFORM.get(target)
        if platform_key is None:
            raise ValueError(f"Unsupported ripgrep target '{target}'.")

        platform_info = platforms.get(platform_key)
        if platform_info is None:
            raise RuntimeError(f"Platform '{platform_key}' not found in manifest {manifest_path}.")

        task_configs.append((target, platform_key, platform_info))

    results: dict[str, Path] = {}
    max_workers = min(len(task_configs), max(1, (os.cpu_count() or 1)))

    print("Installing ripgrep binaries for targets: " + ", ".join(targets))

    with ThreadPoolExecutor(max_workers=max_workers) as executor:
        future_map = {
            executor.submit(
                _fetch_single_rg,
                vendor_dir,
                target,
                platform_key,
                platform_info,
                manifest_path,
            ): target
            for target, platform_key, platform_info in task_configs
        }

        for future in as_completed(future_map):
            target = future_map[future]
            results[target] = future.result()
            print(f"  installed ripgrep for {target}")

    return [results[target] for target in targets]


def _download_artifacts(workflow_id: str, dest_dir: Path) -> None:
    cmd = [
        "gh",
        "run",
        "download",
        "--dir",
        str(dest_dir),
        "--repo",
        "valknarthing/llmx",
        workflow_id,
    ]
    subprocess.check_call(cmd)


def install_binary_components(
    artifacts_dir: Path,
    vendor_dir: Path,
    targets: Iterable[str],
    component_names: Sequence[str],
) -> None:
    selected_components = [BINARY_COMPONENTS[name] for name in component_names if name in BINARY_COMPONENTS]
    if not selected_components:
        return

    targets = list(targets)
    if not targets:
        return

    for component in selected_components:
        print(
            f"Installing {component.binary_basename} binaries for targets: "
            + ", ".join(targets)
        )
        max_workers = min(len(targets), max(1, (os.cpu_count() or 1)))
        with ThreadPoolExecutor(max_workers=max_workers) as executor:
            futures = {
                executor.submit(
                    _install_single_binary,
                    artifacts_dir,
                    vendor_dir,
                    target,
                    component,
                ): target
                for target in targets
            }
            for future in as_completed(futures):
                installed_path = future.result()
                if installed_path is not None:
                    print(f"  installed {installed_path}")


def _install_single_binary(
    artifacts_dir: Path,
    vendor_dir: Path,
    target: str,
    component: BinaryComponent,
) -> Path | None:
    artifact_subdir = artifacts_dir / target
    archive_name = _archive_name_for_target(component.artifact_prefix, target)
    archive_path = artifact_subdir / archive_name
    if not archive_path.exists():
        print(f"  ⚠️  Skipping {target}: artifact not found (build may have failed)")
        return None

    dest_dir = vendor_dir / target / component.dest_dir
    dest_dir.mkdir(parents=True, exist_ok=True)

    binary_name = (
        f"{component.binary_basename}.exe" if "windows" in target else component.binary_basename
    )
    dest = dest_dir / binary_name
    dest.unlink(missing_ok=True)
    extract_archive(archive_path, "zst", None, dest)
    if "windows" not in target:
        dest.chmod(0o755)
    return dest


def _archive_name_for_target(artifact_prefix: str, target: str) -> str:
    if "windows" in target:
        return f"{artifact_prefix}-{target}.exe.zst"
    return f"{artifact_prefix}-{target}.zst"


def _fetch_single_rg(
    vendor_dir: Path,
    target: str,
    platform_key: str,
    platform_info: dict,
    manifest_path: Path,
) -> Path:
    providers = platform_info.get("providers", [])
    if not providers:
        raise RuntimeError(f"No providers listed for platform '{platform_key}' in {manifest_path}.")

    url = providers[0]["url"]
    archive_format = platform_info.get("format", "zst")
    archive_member = platform_info.get("path")

    dest_dir = vendor_dir / target / "path"
    dest_dir.mkdir(parents=True, exist_ok=True)

    is_windows = platform_key.startswith("win")
    binary_name = "rg.exe" if is_windows else "rg"
    dest = dest_dir / binary_name

    with tempfile.TemporaryDirectory() as tmp_dir_str:
        tmp_dir = Path(tmp_dir_str)
        archive_filename = os.path.basename(urlparse(url).path)
        download_path = tmp_dir / archive_filename
        _download_file(url, download_path)

        dest.unlink(missing_ok=True)
        extract_archive(download_path, archive_format, archive_member, dest)

    if not is_windows:
        dest.chmod(0o755)

    return dest


def _download_file(url: str, dest: Path) -> None:
    dest.parent.mkdir(parents=True, exist_ok=True)
    with urlopen(url) as response, open(dest, "wb") as out:
        shutil.copyfileobj(response, out)


def extract_archive(
    archive_path: Path,
    archive_format: str,
    archive_member: str | None,
    dest: Path,
) -> None:
    dest.parent.mkdir(parents=True, exist_ok=True)

    if archive_format == "zst":
        output_path = archive_path.parent / dest.name
        subprocess.check_call(
            ["zstd", "-f", "-d", str(archive_path), "-o", str(output_path)]
        )
        shutil.move(str(output_path), dest)
        return

    if archive_format == "tar.gz":
        if not archive_member:
            raise RuntimeError("Missing 'path' for tar.gz archive in DotSlash manifest.")
        with tarfile.open(archive_path, "r:gz") as tar:
            try:
                member = tar.getmember(archive_member)
            except KeyError as exc:
                raise RuntimeError(
                    f"Entry '{archive_member}' not found in archive {archive_path}."
                ) from exc
            tar.extract(member, path=archive_path.parent, filter="data")
        extracted = archive_path.parent / archive_member
        shutil.move(str(extracted), dest)
        return

    if archive_format == "zip":
        if not archive_member:
            raise RuntimeError("Missing 'path' for zip archive in DotSlash manifest.")
        with zipfile.ZipFile(archive_path) as archive:
            try:
                with archive.open(archive_member) as src, open(dest, "wb") as out:
                    shutil.copyfileobj(src, out)
            except KeyError as exc:
                raise RuntimeError(
                    f"Entry '{archive_member}' not found in archive {archive_path}."
                ) from exc
        return

    raise RuntimeError(f"Unsupported archive format '{archive_format}'.")


def _load_manifest(manifest_path: Path) -> dict:
    cmd = ["dotslash", "--", "parse", str(manifest_path)]
    stdout = subprocess.check_output(cmd, text=True)
    try:
        manifest = json.loads(stdout)
    except json.JSONDecodeError as exc:
        raise RuntimeError(f"Invalid DotSlash manifest output from {manifest_path}.") from exc

    if not isinstance(manifest, dict):
        raise RuntimeError(
            f"Unexpected DotSlash manifest structure for {manifest_path}: {type(manifest)!r}"
        )

    return manifest


if __name__ == "__main__":
    import sys

    sys.exit(main())