#!/usr/bin/env python3
"""Register the ops-bridge MCP server at user scope in ~/.claude.json.

Usage:
    python scripts/register_mcp.py [--dry-run]

This script:
1. Reads the MCP server config from .mcp.json in the repo root.
2. Calls `claude mcp add-json -s user ops-bridge <config>` to register.
3. Patches the `cwd` field in ~/.claude.json (claude mcp add-json silently drops it).

After running, all Claude Code sessions on this machine have access to the
`ops-bridge` MCP tools — even when opened outside the ops-bridge repo directory.
"""
from __future__ import annotations

import argparse
import json
import subprocess
import sys
from pathlib import Path


REPO_ROOT = Path(__file__).parent.parent
MCP_JSON = REPO_ROOT / ".mcp.json"
CLAUDE_JSON = Path.home() / ".claude.json"
SERVER_NAME = "ops-bridge"


def load_server_config() -> dict:
    data = json.loads(MCP_JSON.read_text())
    servers = data.get("mcpServers", {})
    if SERVER_NAME not in servers:
        raise SystemExit(f"ERROR: '{SERVER_NAME}' not found in {MCP_JSON}")
    return servers[SERVER_NAME]


def register(config: dict, dry_run: bool) -> None:
    config_json = json.dumps(config)
    cmd = ["claude", "mcp", "add-json", "-s", "user", SERVER_NAME, config_json]
    print(f"→ Running: {' '.join(cmd[:6])} '<config>'")
    if not dry_run:
        result = subprocess.run(cmd, capture_output=True, text=True)
        if result.returncode != 0:
            print(f"FAILED:\n{result.stderr}", file=sys.stderr)
            raise SystemExit(1)
        print(f"  OK: {result.stdout.strip()}")


def patch_cwd(cwd: str, dry_run: bool) -> None:
    """Patch the cwd field that claude mcp add-json silently drops."""
    if not CLAUDE_JSON.exists():
        print(f"WARNING: {CLAUDE_JSON} not found — skipping cwd patch")
        return

    data = json.loads(CLAUDE_JSON.read_text())
    servers = data.setdefault("mcpServers", {})
    if SERVER_NAME not in servers:
        print(f"WARNING: '{SERVER_NAME}' not found in {CLAUDE_JSON} after registration")
        return

    current_cwd = servers[SERVER_NAME].get("cwd")
    if current_cwd == cwd:
        print(f"→ cwd already correct: {cwd}")
        return

    servers[SERVER_NAME]["cwd"] = cwd
    print(f"→ Patching cwd: {cwd}")
    if not dry_run:
        CLAUDE_JSON.write_text(json.dumps(data, indent=2) + "\n")
        print("  OK")


def main() -> None:
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument("--dry-run", action="store_true", help="Show what would be done without making changes")
    args = parser.parse_args()

    if args.dry_run:
        print("[DRY RUN] No changes will be made.\n")

    config = load_server_config()
    cwd = config.get("cwd", str(REPO_ROOT))

    print(f"Registering ops-bridge MCP server from {MCP_JSON}")
    register(config, dry_run=args.dry_run)
    patch_cwd(cwd, dry_run=args.dry_run)

    if not args.dry_run:
        print("\nDone. Restart Claude Code for the changes to take effect.")
    else:
        print("\n[DRY RUN complete]")


if __name__ == "__main__":
    main()