# Upstream servers
upstream frontend-manamana {
    server frontend-manamana:3000;
}

upstream auth-manamana {
    server auth-manamana:8000;
}

upstream account-manamana {
    server account-manamana:8000;
}

upstream data-manamana {
    server data-manamana:8000;
}

# Rate limiting
limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;
limit_req_zone $binary_remote_addr zone=auth:10m rate=5r/s;

# Main server block
server {
    listen 80;
    server_name localhost;
    
    # Security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "no-referrer-when-downgrade" always;
    add_header Content-Security-Policy "default-src 'self' http: https: data: blob: 'unsafe-inline'" always;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_proxied expired no-cache no-store private must-revalidate auth;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/javascript
        application/xml+rss
        application/json;

    # Frontend - Next.js
    location / {
        proxy_pass http://frontend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_cache_bypass $http_upgrade;
        proxy_read_timeout 86400;
    }

    # WebSocket support for Next.js hot reload
    location /_next/webpack-hmr {
        proxy_pass http://frontend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }

    # API Gateway - Authentication Service
    location /api/auth/ {
        limit_req zone=auth burst=20 nodelay;
        
        proxy_pass http://auth-service/;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Authorization $http_authorization;
        
        # CORS headers
        add_header Access-Control-Allow-Origin "*" always;
        add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" always;
        add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization" always;
        add_header Access-Control-Expose-Headers "Content-Length,Content-Range" always;
        
        if ($request_method = 'OPTIONS') {
            add_header Access-Control-Allow-Origin "*";
            add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS";
            add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization";
            add_header Access-Control-Max-Age 1728000;
            add_header Content-Type 'text/plain; charset=utf-8';
            add_header Content-Length 0;
            return 204;
        }
    }

    # API Gateway - Account Service
    location /api/account/ {
        limit_req zone=api burst=20 nodelay;
        
        proxy_pass http://account-service/;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Authorization $http_authorization;
        
        # File upload support
        client_max_body_size 10M;
        
        # CORS headers
        add_header Access-Control-Allow-Origin "*" always;
        add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS, PATCH" always;
        add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization" always;
        add_header Access-Control-Expose-Headers "Content-Length,Content-Range" always;
        
        if ($request_method = 'OPTIONS') {
            add_header Access-Control-Allow-Origin "*";
            add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS, PATCH";
            add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization";
            add_header Access-Control-Max-Age 1728000;
            add_header Content-Type 'text/plain; charset=utf-8';
            add_header Content-Length 0;
            return 204;
        }
    }

    # API Gateway - Data Service
    location /api/data/ {
        limit_req zone=api burst=20 nodelay;
        
        proxy_pass http://data-service/;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Authorization $http_authorization;
        
        # CORS headers
        add_header Access-Control-Allow-Origin "*" always;
        add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" always;
        add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization" always;
        add_header Access-Control-Expose-Headers "Content-Length,Content-Range" always;
        
        if ($request_method = 'OPTIONS') {
            add_header Access-Control-Allow-Origin "*";
            add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS";
            add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization";
            add_header Access-Control-Max-Age 1728000;
            add_header Content-Type 'text/plain; charset=utf-8';
            add_header Content-Length 0;
            return 204;
        }
    }

    # Health check endpoint
    location /health {
        access_log off;
        return 200 "healthy\n";
        add_header Content-Type text/plain;
    }

    # Static files caching
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
        add_header X-Content-Type-Options nosniff;
    }

    # Error pages
    error_page 404 /404.html;
    error_page 500 502 503 504 /50x.html;
    
    location = /50x.html {
        root /usr/share/nginx/html;
    }
}