#!/usr/bin/env bash
# =============================================================================
# Velocity Backend — Recovery + Investor Demo Seed
# =============================================================================
# Run this on the production server (via SSH) to:
#   1. Diagnose why the FastAPI backend is down (502 gateway)
#   2. Restart the uvicorn service on port 8001
#   3. Verify the /health endpoint responds through nginx
#   4. Run the iPad investor-demo seed script to populate 50 realistic
#      clients, 11 properties with Unsplash media, calendar events, and tasks
#
# Usage:
#   ssh ubuntu@<SERVER_IP>
#   cd /path/to/Project_Velocity
#   bash backend/scripts/restore_and_seed_demo.sh
#
# Prerequisites on server:
#   - Python 3.11+
#   - backend/.env with DATABASE_URL or VELOCITY_DB_* vars set
#   - asyncpg installed (pip install -r backend/requirements.txt)
# =============================================================================

set -euo pipefail

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
BACKEND_DIR="$REPO_ROOT/backend"
VENV_PATH="${VENV_PATH:-$REPO_ROOT/.venv}"
UVICORN_PORT="${UVICORN_PORT:-8001}"
UVICORN_WORKERS="${UVICORN_WORKERS:-2}"
OPERATOR_EMAIL="${VELOCITY_DEMO_OPERATOR_EMAIL:-sayan@desineuron.in}"

echo ""
echo "============================================================"
echo "  Velocity Backend Recovery + Demo Seed"
echo "  Server: $(hostname)"
echo "  Repo:   $REPO_ROOT"
echo "  Port:   $UVICORN_PORT"
echo "============================================================"
echo ""

# ── Step 1: Diagnose ─────────────────────────────────────────────────────────
echo "▶ Step 1/4 — Diagnosing current process state"

PIDS=$(lsof -ti tcp:"$UVICORN_PORT" 2>/dev/null || true)
if [ -n "$PIDS" ]; then
    echo "  ✓ Found process(es) on port $UVICORN_PORT: $PIDS"
    echo "  Killing stale/hung processes..."
    kill -9 $PIDS 2>/dev/null || true
    sleep 1
else
    echo "  ✗ No process on port $UVICORN_PORT — backend is down. Will restart."
fi

# Check systemd service if present
if systemctl list-units --full --all | grep -q "velocity-backend"; then
    echo "  Found systemd unit: velocity-backend"
    sudo systemctl stop velocity-backend 2>/dev/null || true
fi

# ── Step 2: Activate venv and verify deps ────────────────────────────────────
echo ""
echo "▶ Step 2/4 — Activating virtualenv and verifying dependencies"

if [ -f "$VENV_PATH/bin/activate" ]; then
    source "$VENV_PATH/bin/activate"
    echo "  ✓ Activated venv: $VENV_PATH"
else
    echo "  ! No venv at $VENV_PATH — using system Python"
fi

PYTHON="${PYTHON:-python3}"

# Quick dep check
$PYTHON -c "import fastapi, uvicorn, asyncpg, dotenv" 2>/dev/null || {
    echo "  Installing backend requirements..."
    $PYTHON -m pip install --quiet -r "$BACKEND_DIR/requirements.txt"
}
echo "  ✓ Dependencies OK"

# ── Step 3: Start uvicorn ─────────────────────────────────────────────────────
echo ""
echo "▶ Step 3/4 — Starting uvicorn on port $UVICORN_PORT"

cd "$REPO_ROOT"
LOG_FILE="/tmp/velocity_backend_$(date +%Y%m%d_%H%M%S).log"

nohup $PYTHON -m uvicorn backend.main:app \
    --host 127.0.0.1 \
    --port "$UVICORN_PORT" \
    --workers "$UVICORN_WORKERS" \
    --log-level info \
    --timeout-keep-alive 75 \
    > "$LOG_FILE" 2>&1 &

UVICORN_PID=$!
echo "  uvicorn PID: $UVICORN_PID  Log: $LOG_FILE"

# Wait for it to bind
echo "  Waiting for backend to accept connections..."
MAX_WAIT=30
WAITED=0
until curl -sf "http://127.0.0.1:$UVICORN_PORT/health" > /dev/null 2>&1; do
    sleep 1
    WAITED=$((WAITED + 1))
    if [ $WAITED -ge $MAX_WAIT ]; then
        echo ""
        echo "  ✗ Backend did not start within ${MAX_WAIT}s. Last log output:"
        tail -40 "$LOG_FILE"
        exit 1
    fi
    echo -n "."
done
echo ""

HEALTH=$(curl -sf "http://127.0.0.1:$UVICORN_PORT/health")
echo "  ✓ Backend healthy: $HEALTH"

# Verify nginx can reach it
echo ""
echo "  Checking nginx → backend proxy..."
if curl -sf "https://api.desineuron.in/health" > /dev/null 2>&1; then
    echo "  ✓ api.desineuron.in/health is UP — 502 is resolved."
else
    echo "  ! api.desineuron.in/health still failing."
    echo "    Check: sudo nginx -t && sudo systemctl reload nginx"
    echo "    Continuing to seed anyway (backend is healthy on localhost)."
fi

# ── Step 4: Seed investor demo data ──────────────────────────────────────────
echo ""
echo "▶ Step 4/4 — Running iPad investor demo seed"
echo "  Operator: $OPERATOR_EMAIL"
echo "  Target:   50 clients, 11 properties, media, tasks, calendar events"
echo ""

cd "$REPO_ROOT"
$PYTHON backend/scripts/seed_ipad_investor_demo.py \
    --operator-email "$OPERATOR_EMAIL" \
    ${VELOCITY_DEMO_TENANT_ID:+--tenant-id "$VELOCITY_DEMO_TENANT_ID"}

echo ""
echo "============================================================"
echo "  ✅ Recovery complete."
echo ""
echo "  Backend:  http://127.0.0.1:$UVICORN_PORT (PID $UVICORN_PID)"
echo "  Public:   https://api.desineuron.in"
echo "  Log:      $LOG_FILE"
echo ""
echo "  The iPad dashboard will show live data on next refresh."
echo "  Tap 'Updated now' in the header to trigger an immediate sync."
echo "============================================================"
echo ""