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

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
BACKEND_DIR="$ROOT_DIR/backend"
FRONTEND_DIR="$ROOT_DIR/frontend"
LOG_ROOT="$ROOT_DIR/logs"
RUN_ID="$(date +"%Y%m%d-%H%M%S")"
RUN_DIR="$LOG_ROOT/run-$RUN_ID"
LATEST_LINK="$LOG_ROOT/latest"

BACKEND_HOST="${BACKEND_HOST:-127.0.0.1}"
BACKEND_PORT="${BACKEND_PORT:-8000}"
FRONTEND_HOST="${FRONTEND_HOST:-127.0.0.1}"
FRONTEND_PORT="${FRONTEND_PORT:-5173}"
BACKEND_RELOAD="${BACKEND_RELOAD:-1}"
AUTO_INSTALL="${AUTO_INSTALL:-0}"
FOLLOW_LOGS="${FOLLOW_LOGS:-0}"
CONDA_ENV="${CONDA_ENV:-pjctrl}"

# Python path detection (prefer conda env)
PYTHON_BIN=""
detect_python() {
  # Check for conda environment
  local conda_python
  if command -v conda >/dev/null 2>&1; then
    conda_python="$(conda run -n "$CONDA_ENV" which python 2>/dev/null || true)"
    if [[ -n "$conda_python" && -x "$conda_python" ]]; then
      PYTHON_BIN="$conda_python"
      return
    fi
  fi
  # Fallback to system python3
  if command -v python3 >/dev/null 2>&1; then
    PYTHON_BIN="python3"
    return
  fi
  log "ERROR: No Python interpreter found"
  exit 1
}

ENV_LOG=""
RUN_LOG=""
HEALTH_LOG=""

usage() {
  cat <<'EOF'
Usage: ./projectctl.sh [start|stop|status|health]

Commands:
  start   Check environment, start backend/frontend, run health checks
  stop    Stop backend/frontend based on latest pid files
  status  Show current process status from latest pid files
  health  Run health checks against running services

Environment variables:
  BACKEND_HOST     (default: 127.0.0.1)
  BACKEND_PORT     (default: 8000)
  FRONTEND_HOST    (default: 127.0.0.1)
  FRONTEND_PORT    (default: 5173)
  BACKEND_RELOAD   (default: 1) use 0 to disable --reload
  AUTO_INSTALL     (default: 0) set 1 to auto npm install if missing
  FOLLOW_LOGS      (default: 0) set 1 to tail logs after start
  CONDA_ENV        (default: pjctrl) conda environment name for backend
EOF
}

log() {
  local msg="$*"
  local ts
  ts="$(date +"%H:%M:%S")"
  echo "[$ts] $msg" | tee -a "$RUN_LOG"
}

env_log() {
  echo "$*" >> "$ENV_LOG"
}

health_log() {
  echo "$*" | tee -a "$HEALTH_LOG"
}

ensure_dirs() {
  mkdir -p "$RUN_DIR"
  mkdir -p "$LOG_ROOT"
  ln -sfn "$RUN_DIR" "$LATEST_LINK"
  ENV_LOG="$RUN_DIR/env.log"
  RUN_LOG="$RUN_DIR/run.log"
  HEALTH_LOG="$RUN_DIR/health.log"
}

require_cmds() {
  local missing=()
  for cmd in "$@"; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
      missing+=("$cmd")
    fi
  done
  if [[ ${#missing[@]} -gt 0 ]]; then
    log "ERROR: Missing required commands: ${missing[*]}"
    exit 1
  fi
}

get_env_value() {
  local key="$1"
  local file="$2"
  local line
  line="$(grep -E "^${key}=" "$file" | tail -n1 || true)"
  if [[ -z "$line" ]]; then
    echo ""
    return
  fi
  local val="${line#*=}"
  val="$(printf '%s' "$val" | sed -e 's/#.*$//' -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')"
  echo "$val"
}

check_env_file() {
  local env_file="$BACKEND_DIR/.env"
  if [[ ! -f "$env_file" ]]; then
    log "WARN: backend/.env not found. Copy backend/.env.example and set values."
    return 1
  fi

  local required_keys=(
    MYSQL_HOST
    MYSQL_PORT
    MYSQL_USER
    MYSQL_PASSWORD
    MYSQL_DATABASE
    REDIS_HOST
    REDIS_PORT
    JWT_SECRET_KEY
    AUTH_API_URL
    SYSTEM_ADMIN_EMAIL
  )
  local optional_keys=(
    ENCRYPTION_MASTER_KEY
  )

  env_log "Env file: $env_file"
  for key in "${required_keys[@]}"; do
    local val
    val="$(get_env_value "$key" "$env_file")"
    if [[ -z "$val" ]]; then
      log "ERROR: Missing or empty env key: $key"
      env_log "MISSING: $key"
      return 1
    fi
    env_log "OK: $key"
  done

  for key in "${optional_keys[@]}"; do
    local val
    val="$(get_env_value "$key" "$env_file")"
    if [[ -z "$val" ]]; then
      log "WARN: Optional env key not set: $key"
      env_log "WARN: $key not set"
    else
      env_log "OK: $key"
    fi
  done

  return 0
}

check_python_deps() {
  "$PYTHON_BIN" - <<'PY'
import importlib
import sys

required = ["fastapi", "uvicorn", "sqlalchemy", "redis", "pydantic", "alembic"]
missing = []
for mod in required:
    try:
        importlib.import_module(mod)
    except Exception:
        missing.append(mod)

if missing:
    sys.stderr.write("Missing python packages: " + ", ".join(missing) + "\n")
    sys.exit(1)
PY
}

check_redis() {
  local env_file="$BACKEND_DIR/.env"
  local redis_host redis_port
  redis_host="$(get_env_value "REDIS_HOST" "$env_file")"
  redis_port="$(get_env_value "REDIS_PORT" "$env_file")"
  redis_host="${redis_host:-localhost}"
  redis_port="${redis_port:-6379}"

  if command -v redis-cli >/dev/null 2>&1; then
    if ! redis-cli -h "$redis_host" -p "$redis_port" ping >/dev/null 2>&1; then
      log "WARN: Redis not reachable at $redis_host:$redis_port"
      return 1
    fi
    env_log "Redis: OK ($redis_host:$redis_port)"
  else
    # Try nc as fallback
    if command -v nc >/dev/null 2>&1; then
      if ! nc -z "$redis_host" "$redis_port" >/dev/null 2>&1; then
        log "WARN: Redis port not open at $redis_host:$redis_port"
        return 1
      fi
      env_log "Redis: Port reachable ($redis_host:$redis_port)"
    else
      log "WARN: Cannot verify Redis (no redis-cli or nc)"
    fi
  fi
  return 0
}

check_mysql() {
  local env_file="$BACKEND_DIR/.env"
  local mysql_host mysql_port
  mysql_host="$(get_env_value "MYSQL_HOST" "$env_file")"
  mysql_port="$(get_env_value "MYSQL_PORT" "$env_file")"
  mysql_host="${mysql_host:-localhost}"
  mysql_port="${mysql_port:-3306}"

  # Just check if port is reachable (don't require mysql client)
  if command -v nc >/dev/null 2>&1; then
    if ! nc -z -w 3 "$mysql_host" "$mysql_port" >/dev/null 2>&1; then
      log "WARN: MySQL port not reachable at $mysql_host:$mysql_port"
      return 1
    fi
    env_log "MySQL: Port reachable ($mysql_host:$mysql_port)"
  else
    log "WARN: Cannot verify MySQL connectivity (no nc command)"
  fi
  return 0
}

check_node_deps() {
  if [[ ! -d "$FRONTEND_DIR/node_modules" ]]; then
    if [[ "$AUTO_INSTALL" == "1" ]]; then
      log "node_modules missing; running npm install..."
      (cd "$FRONTEND_DIR" && npm install)
    else
      log "ERROR: frontend/node_modules missing. Run npm install or set AUTO_INSTALL=1."
      exit 1
    fi
  fi
}

port_in_use() {
  local port="$1"
  if command -v lsof >/dev/null 2>&1; then
    lsof -iTCP:"$port" -sTCP:LISTEN -n -P >/dev/null 2>&1
    return $?
  fi
  if command -v nc >/dev/null 2>&1; then
    nc -z 127.0.0.1 "$port" >/dev/null 2>&1
    return $?
  fi
  return 1
}

check_ports() {
  if port_in_use "$BACKEND_PORT"; then
    log "ERROR: Port $BACKEND_PORT is already in use."
    exit 1
  fi
  if port_in_use "$FRONTEND_PORT"; then
    log "ERROR: Port $FRONTEND_PORT is already in use."
    exit 1
  fi
}

start_backend() {
  local reload_args=()
  if [[ "$BACKEND_RELOAD" == "1" ]]; then
    reload_args=("--reload")
  fi

  log "Starting backend on $BACKEND_HOST:$BACKEND_PORT (python: $PYTHON_BIN)..."
  (
    cd "$BACKEND_DIR"
    nohup env PYTHONPATH="$BACKEND_DIR" \
      "$PYTHON_BIN" -m uvicorn app.main:app \
      --host "$BACKEND_HOST" \
      --port "$BACKEND_PORT" \
      "${reload_args[@]+"${reload_args[@]}"}" \
      > "$RUN_DIR/backend.log" 2>&1 &
    echo $! > "$RUN_DIR/backend.pid"
  )
}

start_frontend() {
  log "Starting frontend on $FRONTEND_HOST:$FRONTEND_PORT..."
  (
    cd "$FRONTEND_DIR"
    nohup npm run dev -- --host "$FRONTEND_HOST" --port "$FRONTEND_PORT" \
      > "$RUN_DIR/frontend.log" 2>&1 &
    echo $! > "$RUN_DIR/frontend.pid"
  )
}

wait_for_url() {
  local url="$1"
  local name="$2"
  local retries="${3:-30}"
  local delay="${4:-1}"
  local i=0

  while (( i < retries )); do
    if curl -fsS "$url" >/dev/null 2>&1; then
      health_log "$(date +"%Y-%m-%d %H:%M:%S") OK $name $url"
      return 0
    fi
    sleep "$delay"
    i=$((i + 1))
  done

  health_log "$(date +"%Y-%m-%d %H:%M:%S") FAIL $name $url"
  return 1
}

run_health_checks() {
  log "Running health checks..."
  local backend_url="http://$BACKEND_HOST:$BACKEND_PORT/health"
  local frontend_url="http://$FRONTEND_HOST:$FRONTEND_PORT/"

  wait_for_url "$backend_url" "backend" 40 1 || log "WARN: Backend health check failed."
  wait_for_url "$frontend_url" "frontend" 40 1 || log "WARN: Frontend health check failed."
}

latest_run_dir() {
  if [[ -L "$LATEST_LINK" ]]; then
    readlink "$LATEST_LINK"
    return
  fi
  ls -dt "$LOG_ROOT"/run-* 2>/dev/null | head -n1 || true
}

stop_service() {
  local name="$1"
  local pidfile="$2"
  if [[ ! -f "$pidfile" ]]; then
    echo "$name: pid file not found."
    return
  fi
  local pid
  pid="$(cat "$pidfile")"
  if kill -0 "$pid" >/dev/null 2>&1; then
    echo "Stopping $name (pid $pid)..."
    # Kill child processes first (for uvicorn workers, vite children, etc.)
    if command -v pgrep >/dev/null 2>&1; then
      local children
      children="$(pgrep -P "$pid" 2>/dev/null || true)"
      if [[ -n "$children" ]]; then
        echo "$children" | xargs kill 2>/dev/null || true
      fi
    fi
    kill -TERM "$pid" 2>/dev/null || true
    # Wait briefly for graceful shutdown
    sleep 1
    # Force kill if still running
    kill -0 "$pid" 2>/dev/null && kill -KILL "$pid" 2>/dev/null || true
  else
    echo "$name: process not running."
  fi
  rm -f "$pidfile"
}

status_service() {
  local name="$1"
  local pidfile="$2"
  if [[ ! -f "$pidfile" ]]; then
    echo "$name: pid file not found."
    return
  fi
  local pid
  pid="$(cat "$pidfile")"
  if kill -0 "$pid" >/dev/null 2>&1; then
    echo "$name: running (pid $pid)"
  else
    echo "$name: not running"
  fi
}

start() {
  ensure_dirs
  log "Run directory: $RUN_DIR"

  require_cmds node npm curl
  detect_python
  env_log "Timestamp: $(date -u +"%Y-%m-%dT%H:%M:%SZ")"
  env_log "Python: $("$PYTHON_BIN" --version 2>&1)"
  env_log "Python Path: $PYTHON_BIN"
  env_log "Node: $(node --version 2>&1)"
  env_log "NPM: $(npm --version 2>&1)"

  check_env_file
  check_python_deps
  check_node_deps
  check_redis || true  # Warn but don't fail
  check_mysql || true  # Warn but don't fail
  check_ports

  start_backend
  start_frontend
  run_health_checks

  log "Logs: $RUN_DIR"
  log "Backend log: $RUN_DIR/backend.log"
  log "Frontend log: $RUN_DIR/frontend.log"
  log "Health log: $RUN_DIR/health.log"

  if [[ "$FOLLOW_LOGS" == "1" ]]; then
    log "Tailing logs. Press Ctrl+C to stop tailing."
    tail -n 200 -f "$RUN_DIR/backend.log" "$RUN_DIR/frontend.log"
  fi
}

stop() {
  local dir
  dir="$(latest_run_dir)"
  if [[ -z "$dir" ]]; then
    echo "No run directory found."
    return
  fi
  stop_service "backend" "$dir/backend.pid"
  stop_service "frontend" "$dir/frontend.pid"
}

status() {
  local dir
  dir="$(latest_run_dir)"
  if [[ -z "$dir" ]]; then
    echo "No run directory found."
    return
  fi
  status_service "backend" "$dir/backend.pid"
  status_service "frontend" "$dir/frontend.pid"
}

health() {
  local dir
  dir="$(latest_run_dir)"
  if [[ -z "$dir" ]]; then
    echo "No run directory found."
    return
  fi
  RUN_DIR="$dir"
  RUN_LOG="$dir/run.log"
  HEALTH_LOG="$dir/health.log"
  run_health_checks
}

case "${1:-start}" in
  start) start ;;
  stop) stop ;;
  status) status ;;
  health) health ;;
  -h|--help) usage ;;
  *) usage; exit 1 ;;
esac