#!/usr/bin/env bash
# =============================================================================
# prepare-app.sh — Deploy Task Manager to Azure VM
#
# This script:
#   1. Creates an Azure Resource Group
#   2. Creates a VM with Docker pre-installed (cloud-init)
#   3. Opens ports 80, 443 for HTTPS
#   4. Uploads all application files via SCP
#   5. Starts all containers with docker compose
#
# Prerequisites:
#   - Azure CLI installed and logged in (az login)
#   - Azure for Students subscription active
#   - .env file configured (copy from env.example)
#
# Usage:
#   ./prepare-app.sh
# =============================================================================
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"

# ---- Load configuration -----------------------------------------------
if [ ! -f "$SCRIPT_DIR/.env" ]; then
    echo "ERROR: .env file not found!"
    echo "  cp env.example .env && nano .env"
    exit 1
fi

source "$SCRIPT_DIR/.env"

RG="${AZURE_RESOURCE_GROUP:-taskmanager-rg}"
LOC="${AZURE_LOCATION:-westeurope}"
VM="${AZURE_VM_NAME:-taskmanager-vm}"
SIZE="${AZURE_VM_SIZE:-Standard_B1s}"
DNS="${AZURE_DNS_LABEL:-taskmanager-gs699he}"
ADMIN="azureuser"

FQDN="${DNS}.${LOC}.cloudapp.azure.com"
SSH_KEY="$HOME/.ssh/sk1_taskmanager"

echo "============================================="
echo "  Task Manager — Azure Cloud Deployment"
echo "============================================="
echo ""
echo "  Resource Group: $RG"
echo "  Location:       $LOC"
echo "  VM Name:        $VM"
echo "  VM Size:        $SIZE"
echo "  DNS:            $FQDN"
echo ""

# ---- Step 1: Check Azure CLI ------------------------------------------
echo "[1/7] Checking Azure CLI..."
if ! az account show &>/dev/null; then
    echo "ERROR: Not logged in. Run: az login"
    exit 1
fi
SUB_NAME=$(az account show --query "name" -o tsv)
echo "      ✓ Subscription: $SUB_NAME"

# ---- Step 2: Generate SSH key if needed --------------------------------
echo "[2/7] Checking SSH key..."
if [ ! -f "$SSH_KEY" ]; then
    ssh-keygen -t ed25519 -f "$SSH_KEY" -N "" -q
    echo "      ✓ Created new SSH key: $SSH_KEY"
else
    echo "      ✓ Using existing key: $SSH_KEY"
fi

# ---- Step 3: Create Resource Group -------------------------------------
echo "[3/7] Creating Resource Group '$RG'..."
az group create --name "$RG" --location "$LOC" -o none
echo "      ✓ Resource Group ready"

# ---- Step 4: Create VM ------------------------------------------------
echo "[4/7] Creating VM '$VM' (this takes ~2 minutes)..."
az vm create \
    --resource-group "$RG" \
    --name "$VM" \
    --image Ubuntu2404 \
    --size "$SIZE" \
    --admin-username "$ADMIN" \
    --ssh-key-values "$SSH_KEY.pub" \
    --public-ip-address-dns-name "$DNS" \
    --custom-data "$SCRIPT_DIR/cloud-init.yaml" \
    --output none

echo "      ✓ VM created: $FQDN"

# ---- Step 5: Open firewall ports --------------------------------------
echo "[5/7] Opening ports 80 and 443..."
az vm open-port --resource-group "$RG" --name "$VM" --port 80 --priority 1010 -o none
az vm open-port --resource-group "$RG" --name "$VM" --port 443 --priority 1020 -o none
echo "      ✓ Ports 80, 443 open"

# ---- Step 6: Wait for Docker and upload files --------------------------
echo "[6/7] Waiting for Docker installation (cloud-init ~60s)..."
SSH_CMD="ssh -o StrictHostKeyChecking=no -i $SSH_KEY $ADMIN@$FQDN"

# Wait for cloud-init to finish
for i in $(seq 1 30); do
    if $SSH_CMD "command -v docker" &>/dev/null; then
        echo "      ✓ Docker installed"
        break
    fi
    echo "      ... waiting ($i/30)"
    sleep 10
done

# Verify Docker
if ! $SSH_CMD "docker --version" &>/dev/null; then
    echo "ERROR: Docker not available after 5 minutes."
    echo "SSH in and check: $SSH_CMD"
    exit 1
fi

# Upload application files
echo "      Uploading application files..."
cd "$SCRIPT_DIR"
tar czf /tmp/taskmanager-app.tar.gz \
    --exclude='.git' \
    --exclude='docs' \
    --exclude='backups' \
    --exclude='*.pdf' \
    --exclude='*.tex' \
    --exclude='*.aux' \
    --exclude='*.log' \
    --exclude='*.png' \
    --exclude='node_modules' \
    api/ frontend/ db/ caddy/ docker-compose.yaml .env

scp -o StrictHostKeyChecking=no -i "$SSH_KEY" \
    /tmp/taskmanager-app.tar.gz "$ADMIN@$FQDN:/tmp/"
rm -f /tmp/taskmanager-app.tar.gz

$SSH_CMD bash -s <<'EXTRACT'
    sudo mkdir -p /opt/taskmanager
    sudo tar xzf /tmp/taskmanager-app.tar.gz -C /opt/taskmanager
    sudo chown -R $USER:$USER /opt/taskmanager
    rm -f /tmp/taskmanager-app.tar.gz
EXTRACT
echo "      ✓ Files uploaded"

# ---- Step 7: Start containers -----------------------------------------
echo "[7/7] Starting application containers..."
$SSH_CMD bash -s "$FQDN" <<'START'
    cd /opt/taskmanager
    echo "DOMAIN_NAME=$1" | sudo tee -a .env > /dev/null
    sudo docker compose down 2>/dev/null || true
    sudo docker compose up -d --build
    echo ""
    echo "Waiting for containers to start (30s)..."
    sleep 30
    echo ""
    sudo docker compose ps
START
echo "      ✓ Application started"

# ---- Summary ----------------------------------------------------------
echo ""
echo "============================================="
echo "  ✓ Deployment Complete!"
echo ""
echo "  🌐 URL:  https://$FQDN"
echo "  📍 SSH:  ssh -i $SSH_KEY $ADMIN@$FQDN"
echo ""
echo "  HTTPS certificate may take 1-2 min to provision."
echo ""
echo "  Logs:    ./view-logs.sh"
echo "  Backup:  ./backup-db.sh"
echo "  Remove:  ./remove-app.sh"
echo "============================================="