#!/bin/bash

# ==========================================
# Nanaxe Server Deployment Script
# ==========================================

set -e

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Configuration
COMPOSE_FILE="docker-compose.prod.yml"
BACKUP_DIR="./backups"
LOG_FILE="./logs/deploy-$(date +%Y%m%d-%H%M%S).log"

# ==========================================
# Helper Functions
# ==========================================

log() {
    echo -e "${BLUE}[$(date +'%Y-%m-%d %H:%M:%S')]${NC} $1" | tee -a "$LOG_FILE"
}

error() {
    echo -e "${RED}[ERROR]${NC} $1" | tee -a "$LOG_FILE"
}

success() {
    echo -e "${GREEN}[SUCCESS]${NC} $1" | tee -a "$LOG_FILE"
}

warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1" | tee -a "$LOG_FILE"
}

# ==========================================
# Pre-deployment Checks
# ==========================================

check_prerequisites() {
    log "Checking prerequisites..."
    
    # Check Docker
    if ! command -v docker &> /dev/null; then
        error "Docker is not installed"
        exit 1
    fi
    
    # Check Docker Compose
    if ! docker compose version &> /dev/null; then
        error "Docker Compose is not installed"
        exit 1
    fi
    
    # Check .env file
    if [ ! -f .env ]; then
        error ".env file not found. Please create it from .env.example"
        exit 1
    fi
    
    # Check compose file
    if [ ! -f "$COMPOSE_FILE" ]; then
        error "Compose file $COMPOSE_FILE not found"
        exit 1
    fi
    
    success "Prerequisites check passed"
}

# ==========================================
# Backup
# ==========================================

create_backup() {
    log "Creating backup..."
    
    mkdir -p "$BACKUP_DIR"
    
    # Backup database
    if docker compose ps postgres | grep -q "running"; then
        log "Backing up PostgreSQL database..."
        docker compose exec -T postgres pg_dump -U gitea gitea > "$BACKUP_DIR/db-$(date +%Y%m%d-%H%M%S).sql" 2>/dev/null || warning "Database backup failed"
    fi
    
    # Backup mindmaps
    if [ -d "mindmap-data" ]; then
        log "Backing up mindmaps..."
        tar -czf "$BACKUP_DIR/mindmaps-$(date +%Y%m%d-%H%M%S).tar.gz" mindmap-data/ 2>/dev/null || warning "Mindmaps backup failed"
    fi
    
    success "Backup completed"
}

# ==========================================
# Deployment
# ==========================================

deploy() {
    log "Starting deployment..."
    
    # Pull latest images
    log "Pulling latest images..."
    docker compose -f "$COMPOSE_FILE" pull
    
    # Deploy with zero downtime
    log "Deploying services..."
    docker compose -f "$COMPOSE_FILE" up -d --remove-orphans
    
    success "Deployment completed"
}

# ==========================================
# Health Checks
# ==========================================

health_check() {
    log "Running health checks..."
    
    local max_attempts=30
    local attempt=1
    
    # Wait for services to start
    sleep 10
    
    # Check API
    log "Checking API health..."
    while [ $attempt -le $max_attempts ]; do
        if curl -sf http://localhost:8080/health > /dev/null 2>&1; then
            success "API is healthy"
            break
        fi
        
        if [ $attempt -eq $max_attempts ]; then
            error "API health check failed after $max_attempts attempts"
            show_logs
            exit 1
        fi
        
        log "Attempt $attempt/$max_attempts: API not ready yet..."
        sleep 5
        ((attempt++))
    done
    
    # Check Gitea
    log "Checking Gitea health..."
    attempt=1
    while [ $attempt -le $max_attempts ]; do
        if curl -sf http://localhost:3000/api/healthz > /dev/null 2>&1; then
            success "Gitea is healthy"
            break
        fi
        
        if [ $attempt -eq $max_attempts ]; then
            warning "Gitea health check failed (may still be initializing)"
            break
        fi
        
        log "Attempt $attempt/$max_attempts: Gitea not ready yet..."
        sleep 5
        ((attempt++))
    done
    
    success "All health checks passed"
}

# ==========================================
# Cleanup
# ==========================================

cleanup() {
    log "Cleaning up..."
    
    # Remove old backups (keep last 7)
    if [ -d "$BACKUP_DIR" ]; then
        ls -t "$BACKUP_DIR"/*.sql 2>/dev/null | tail -n +8 | xargs -r rm
        ls -t "$BACKUP_DIR"/*.tar.gz 2>/dev/null | tail -n +8 | xargs -r rm
    fi
    
    # Clean Docker
    docker system prune -f
    docker volume prune -f
    
    success "Cleanup completed"
}

# ==========================================
# Rollback
# ==========================================

rollback() {
    error "Deployment failed! Rolling back..."
    
    # Get previous image
    local previous_image=$(docker images ghcr.io/*/nanaxe-api --format "{{.Repository}}:{{.Tag}}" | grep -v latest | head -1)
    
    if [ -n "$previous_image" ]; then
        log "Reverting to: $previous_image"
        docker compose -f "$COMPOSE_FILE" stop api
        docker compose -f "$COMPOSE_FILE" rm -f api
        docker run -d --name nanaxe-api-rollback \
            --network nanaxe-network \
            -v mindmap-data:/app/mindmaps \
            -e NODE_ENV=production \
            -e PORT=8080 \
            -p 8080:8080 \
            "$previous_image"
        success "Rollback completed"
    else
        error "No previous image found for rollback"
    fi
}

# ==========================================
# Show Logs
# ==========================================

show_logs() {
    log "Showing recent logs..."
    docker compose -f "$COMPOSE_FILE" logs --tail=50
}

# ==========================================
# Main
# ==========================================

main() {
    log "======================================"
    log "Nanaxe Server Deployment"
    log "======================================"
    
    # Create logs directory
    mkdir -p logs
    
    # Run deployment steps
    check_prerequisites
    create_backup
    
    # Deploy with error handling
    if deploy; then
        if health_check; then
            cleanup
            success "======================================"
            success "Deployment completed successfully!"
            success "======================================"
            log "API: http://localhost:8080"
            log "Gitea: http://localhost:3000"
        else
            rollback
            exit 1
        fi
    else
        rollback
        exit 1
    fi
}

# Run main function
main "$@"