#!/usr/bin/env bash
set -euo pipefail

STATE_HUB_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
CLAUDE_JSON="${CLAUDE_JSON:-$HOME/.claude.json}"
SERVER_NAME="${STATE_HUB_MCP_NAME:-state-hub}"
API_BASE="${API_BASE:-}"
MCP_URL="${MCP_URL:-}"
DRY_RUN=0

usage() {
  cat <<'USAGE'
Usage: scripts/register-mcp.sh [--url URL] [--api-base URL] [--dry-run]

Registers the State Hub MCP server for Claude Code.

Options:
  --url URL       MCP SSE URL to register. Defaults to local :8001 or tunnel :18001.
  --api-base URL  State Hub API URL used for reachability checks.
  --dry-run      Print what would happen without changing Claude config.
  -h, --help     Show this help.
USAGE
}

while [ "$#" -gt 0 ]; do
  case "$1" in
    --url)
      MCP_URL="${2:-}"
      shift 2
      ;;
    --api-base)
      API_BASE="${2:-}"
      shift 2
      ;;
    --dry-run)
      DRY_RUN=1
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "ERROR: unknown argument: $1" >&2
      usage >&2
      exit 2
      ;;
  esac
done

status() {
  printf '%s\n' "$*"
}

api_healthy() {
  local base="$1"
  curl -fsS --max-time 2 "${base%/}/state/health" >/dev/null 2>&1
}

port_open() {
  local host="$1"
  local port="$2"
  timeout 2 bash -c ":</dev/tcp/$host/$port" >/dev/null 2>&1
}

if [ -z "$API_BASE" ]; then
  if api_healthy "http://127.0.0.1:8000"; then
    API_BASE="http://127.0.0.1:8000"
  elif api_healthy "http://127.0.0.1:18000"; then
    API_BASE="http://127.0.0.1:18000"
  else
    API_BASE="http://127.0.0.1:8000"
  fi
fi

if [ -z "$MCP_URL" ]; then
  if port_open 127.0.0.1 8001; then
    MCP_URL="http://127.0.0.1:8001/sse"
  elif port_open 127.0.0.1 18001; then
    MCP_URL="http://127.0.0.1:18001/sse"
  elif [ "$API_BASE" = "http://127.0.0.1:18000" ]; then
    MCP_URL="http://127.0.0.1:18001/sse"
  else
    MCP_URL="http://127.0.0.1:8001/sse"
  fi
fi

CONFIG="$(python3 - "$MCP_URL" <<'PY'
import json
import sys

print(json.dumps({"type": "sse", "url": sys.argv[1]}, separators=(",", ":")))
PY
)"

status "State Hub directory: $STATE_HUB_DIR"
status "API health check:     ${API_BASE%/}/state/health"
status "MCP registration:     $SERVER_NAME -> $MCP_URL"

if api_healthy "$API_BASE"; then
  status "OK: State Hub API is reachable."
else
  status "WARN: State Hub API is not reachable at ${API_BASE%/}/state/health."
  status "      Start it with 'make api' or bring up the ops-bridge tunnel."
fi

if ! command -v claude >/dev/null 2>&1; then
  if [ "$DRY_RUN" -eq 1 ]; then
    status "WARN: claude CLI not found on PATH; dry-run will still show the command."
  else
    status "ERROR: claude CLI not found on PATH."
    status "       Install or expose Claude Code CLI, then rerun: make register-mcp"
    exit 1
  fi
fi

CURRENT_URL="$(python3 - "$CLAUDE_JSON" "$SERVER_NAME" <<'PY'
import json
import sys
from pathlib import Path

path = Path(sys.argv[1])
name = sys.argv[2]
if not path.exists():
    print("")
    raise SystemExit
try:
    data = json.loads(path.read_text())
except json.JSONDecodeError:
    print("")
    raise SystemExit
entry = data.get("mcpServers", {}).get(name, {})
print(entry.get("url", ""))
PY
)"

if [ "$CURRENT_URL" = "$MCP_URL" ]; then
  status "OK: $SERVER_NAME is already registered with this URL."
  exit 0
fi

if [ "$DRY_RUN" -eq 1 ]; then
  status "DRY-RUN: would run:"
  status "  claude mcp add-json -s user $SERVER_NAME '$CONFIG'"
  exit 0
fi

claude mcp add-json -s user "$SERVER_NAME" "$CONFIG"

status "OK: registered $SERVER_NAME."
status "Restart Claude Code so the MCP server list is refreshed."