#!/usr/bin/env bash
# watch.sh — Poll git remote for new commits, pull and re-run on change.
# Usage: ./watch.sh [poll_interval_seconds]
#
# Watches the git remote. On new commits:
#   1. git pull
#   2. pip install -r requirements.txt (if changed)
#   3. Re-run ingestion (if parser/docgen/ingest changed)
#   4. Restart MCP server
#
# Ctrl+C to stop.

set -euo pipefail

POLL_INTERVAL="${1:-10}"
MCP_PID=""
LAST_HASH=""

cleanup() {
    echo -e "\n[watch] Shutting down..."
    if [ -n "$MCP_PID" ] && kill -0 "$MCP_PID" 2>/dev/null; then
        kill "$MCP_PID" 2>/dev/null
        echo "[watch] MCP server stopped."
    fi
    exit 0
}
trap cleanup SIGINT SIGTERM

start_mcp() {
    if [ -n "$MCP_PID" ] && kill -0 "$MCP_PID" 2>/dev/null; then
        echo "[watch] Stopping MCP server (pid $MCP_PID)..."
        kill "$MCP_PID" 2>/dev/null
        wait "$MCP_PID" 2>/dev/null || true
    fi
    echo "[watch] Starting MCP server..."
    uv run python mcp_server.py &
    MCP_PID=$!
    echo "[watch] MCP server started (pid $MCP_PID)"
}

get_local_hash() {
    git rev-parse HEAD 2>/dev/null
}

get_remote_hash() {
    git ls-remote origin HEAD 2>/dev/null | cut -f1
}

echo "[watch] Developer Intelligence POC — File Watcher"
echo "[watch] Polling every ${POLL_INTERVAL}s for new commits..."
echo ""

# Initial setup
LAST_HASH=$(get_local_hash)
LAST_REQS=$(md5sum requirements.txt pyproject.toml 2>/dev/null || echo "none")

# Start MCP server
if [ -f "devintel.db" ]; then
    start_mcp
else
    echo "[watch] No database found. Run 'python ingest.py' first, then restart watch.sh"
    echo "[watch] Watching for code changes only..."
fi

while true; do
    sleep "$POLL_INTERVAL"

    # Check remote
    REMOTE_HASH=$(get_remote_hash)
    if [ -z "$REMOTE_HASH" ]; then
        continue
    fi

    LOCAL_HASH=$(get_local_hash)
    if [ "$REMOTE_HASH" = "$LOCAL_HASH" ]; then
        continue
    fi

    echo ""
    echo "[watch] New commit detected: ${LOCAL_HASH:0:8} → ${REMOTE_HASH:0:8}"
    echo "[watch] Pulling..."
    git pull --ff-only origin master

    # Check if requirements changed
    NEW_REQS=$(md5sum requirements.txt pyproject.toml 2>/dev/null || echo "none")
    if [ "$NEW_REQS" != "$LAST_REQS" ]; then
        echo "[watch] Dependencies changed — syncing..."
        uv sync
        LAST_REQS="$NEW_REQS"
    fi

    # Always run db migrations
    echo "[watch] Running db migrations..."
    uv run python -c "from db import init_db; init_db()"

    # Check if ingestion code changed
    CHANGED_FILES=$(git diff --name-only "$LOCAL_HASH" "$REMOTE_HASH")
    NEEDS_REINGEST=false
    for f in $CHANGED_FILES; do
        case "$f" in
            go_parser.py|docgen.py|ingest.py|db.py)
                NEEDS_REINGEST=true
                ;;
        esac
    done

    if [ "$NEEDS_REINGEST" = true ] && [ -f "devintel.db" ]; then
        echo "[watch] Ingestion code changed. Re-running ingestion..."
        uv run python ingest.py
    fi

    # Always restart MCP server on any code change
    if [ -f "devintel.db" ]; then
        start_mcp
    fi

    echo "[watch] Updated to $(get_local_hash | head -c 8). Watching..."
done