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

MOSAIC_HOME="${MOSAIC_HOME:-$HOME/.config/mosaic}"
TOOLS_DIR="$MOSAIC_HOME/tools/excalidraw"
MODE="apply"
SCOPE="user"

err() { echo "[mosaic-excalidraw] ERROR: $*" >&2; }
log() { echo "[mosaic-excalidraw] $*"; }

while [[ $# -gt 0 ]]; do
  case "$1" in
    --check) MODE="check"; shift ;;
    --scope)
      if [[ $# -lt 2 ]]; then
        err "--scope requires a value: user|local"
        exit 2
      fi
      SCOPE="$2"
      shift 2
      ;;
    *)
      err "Unknown argument: $1"
      exit 2
      ;;
  esac
done

require_binary() {
  local name="$1"
  if ! command -v "$name" >/dev/null 2>&1; then
    err "Required binary missing: $name"
    return 1
  fi
}

check_software() {
  require_binary node
  require_binary npm
}

check_tool_dir() {
  [[ -d "$TOOLS_DIR" ]] || { err "Tool dir not found: $TOOLS_DIR"; return 1; }
  [[ -f "$TOOLS_DIR/package.json" ]] || { err "package.json not found in $TOOLS_DIR"; return 1; }
  [[ -f "$TOOLS_DIR/launch.sh" ]] || { err "launch.sh not found in $TOOLS_DIR"; return 1; }
}

check_npm_deps() {
  [[ -d "$TOOLS_DIR/node_modules/@modelcontextprotocol" ]] || return 1
  [[ -d "$TOOLS_DIR/node_modules/@excalidraw" ]] || return 1
  [[ -d "$TOOLS_DIR/node_modules/jsdom" ]] || return 1
}

install_npm_deps() {
  if check_npm_deps; then
    return 0
  fi
  log "Installing npm deps in $TOOLS_DIR..."
  (cd "$TOOLS_DIR" && npm install --silent) || {
    err "npm install failed in $TOOLS_DIR"
    return 1
  }
}

check_claude_config() {
  python3 - <<'PY'
import json
from pathlib import Path

p = Path.home() / ".claude.json"
if not p.exists():
    raise SystemExit(1)
try:
    data = json.loads(p.read_text(encoding="utf-8"))
except Exception:
    raise SystemExit(1)
mcp = data.get("mcpServers")
if not isinstance(mcp, dict):
    raise SystemExit(1)
entry = mcp.get("excalidraw")
if not isinstance(entry, dict):
    raise SystemExit(1)
cmd = entry.get("command", "")
if not cmd.endswith("launch.sh"):
    raise SystemExit(1)
PY
}

apply_claude_config() {
  require_binary claude
  local launch_sh="$TOOLS_DIR/launch.sh"
  claude mcp add --scope user excalidraw -- "$launch_sh"
}

# ── Check mode ────────────────────────────────────────────────────────────────

if [[ "$MODE" == "check" ]]; then
  check_software
  check_tool_dir
  if ! check_npm_deps; then
    err "npm deps not installed in $TOOLS_DIR (run without --check to install)"
    exit 1
  fi
  if ! check_claude_config; then
    err "excalidraw not registered in ~/.claude.json"
    exit 1
  fi
  log "excalidraw MCP is configured and available"
  exit 0
fi

# ── Apply mode ────────────────────────────────────────────────────────────────

check_software
check_tool_dir
install_npm_deps
apply_claude_config
log "excalidraw MCP configured (scope: $SCOPE)"