#!/usr/bin/env python3
"""Install the Kaiju Coder 7 OpenCode provider and lean agent locally."""

from __future__ import annotations

import argparse
import json
import shutil
from pathlib import Path
from typing import Any


ROOT = Path(__file__).resolve().parents[1]
AGENT_SOURCE_CANDIDATES = [
    ROOT / ".opencode/agents/kaiju-coder-7.md",
    ROOT / "agents/kaiju-coder-7.md",
]
CONFIG_SOURCE_CANDIDATES = [
    ROOT / "release/opencode/opencode.kaiju-coder-7.jsonc",
    ROOT / "opencode.kaiju-coder-7.jsonc",
]
PLUGIN_SOURCE_CANDIDATES = [
    ROOT / "scripts/opencode-kaiju-no-autocontinue.mjs",
    ROOT / "opencode-kaiju-no-autocontinue.mjs",
]
PLUGIN_DEST_NAME = "kaiju-no-autocontinue.mjs"


def strip_jsonc(text: str) -> str:
    # The template intentionally stays plain JSON-compatible today. This helper
    # keeps the installer tolerant if comments are added later.
    lines = []
    for line in text.splitlines():
        if line.lstrip().startswith("//"):
            continue
        lines.append(line)
    return "\n".join(lines)


def load_json(path: Path) -> dict[str, Any]:
    if not path.exists():
        return {}
    return json.loads(strip_jsonc(path.read_text(encoding="utf-8")))


def write_json(path: Path, data: dict[str, Any]) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps(data, indent=2) + "\n", encoding="utf-8")


def first_existing(candidates: list[Path], label: str) -> Path:
    for candidate in candidates:
        if candidate.is_file():
            return candidate
    joined = ", ".join(str(candidate) for candidate in candidates)
    raise FileNotFoundError(f"Missing {label}. Looked in: {joined}")


def plugin_list(value: Any) -> list[str]:
    if isinstance(value, str):
        return [value]
    if isinstance(value, list):
        return [item for item in value if isinstance(item, str)]
    return []


def merge_provider(
    existing: dict[str, Any],
    template: dict[str, Any],
    base_url: str | None,
    plugin_path: Path,
) -> dict[str, Any]:
    merged = dict(existing)
    provider = dict(merged.get("provider") or {})
    kaiju = dict((template.get("provider") or {})["kaiju"])
    if base_url:
        options = dict(kaiju.get("options") or {})
        options["baseURL"] = base_url
        kaiju["options"] = options
    provider["kaiju"] = kaiju
    merged["$schema"] = merged.get("$schema") or template.get("$schema", "https://opencode.ai/config.json")
    merged["provider"] = provider
    plugins = plugin_list(merged.get("plugin"))
    plugin_path_str = str(plugin_path)
    if plugin_path_str not in plugins:
        plugins.append(plugin_path_str)
    merged["plugin"] = plugins
    return merged


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument(
        "--config-dir",
        type=Path,
        default=Path.home() / ".config/opencode",
        help="OpenCode config directory to update.",
    )
    parser.add_argument("--base-url", default=None, help="Override Kaiju OpenAI-compatible base URL.")
    parser.add_argument("--dry-run", action="store_true")
    args = parser.parse_args()

    config_path = args.config_dir / "opencode.jsonc"
    agent_dest = args.config_dir / "agents/kaiju-coder-7.md"
    plugin_dest = args.config_dir / PLUGIN_DEST_NAME
    agent_source = first_existing(AGENT_SOURCE_CANDIDATES, "Kaiju Coder 7 OpenCode agent")
    config_source = first_existing(CONFIG_SOURCE_CANDIDATES, "Kaiju Coder 7 OpenCode config")
    plugin_source = first_existing(PLUGIN_SOURCE_CANDIDATES, "Kaiju Coder 7 OpenCode loop guard")
    existing = load_json(config_path)
    template = load_json(config_source)
    merged = merge_provider(existing, template, args.base_url, plugin_dest)

    print(f"Config: {config_path}")
    print(f"Agent:  {agent_dest}")
    print(f"Plugin: {plugin_dest}")
    if args.dry_run:
        print(
            json.dumps(
                {
                    "plugin": merged.get("plugin", []),
                    "kaiju": merged.get("provider", {}).get("kaiju", {}),
                },
                indent=2,
            )
        )
        return 0

    write_json(config_path, merged)
    agent_dest.parent.mkdir(parents=True, exist_ok=True)
    shutil.copy2(agent_source, agent_dest)
    shutil.copy2(plugin_source, plugin_dest)
    print("Installed Kaiju Coder 7 OpenCode profile.")
    print("Run: opencode -m kaiju/kaiju-coder-7 --agent kaiju-coder-7")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())