# ./nginx.conf
# Mount as: ./nginx.conf:/etc/nginx/nginx.conf:ro
#
# Request path:
# Internet -> Caddy (TLS) -> Nginx -> FastAPI service "s1ne:8003"
#
# Nginx directly serves ./static mounted at /usr/share/nginx/html.
# FastAPI handles /api/, /media/, /share/, /healthz, and /readyz.
#
# A separately mounted protected directory is exposed at /files/.
# Example container mount: ./protected:/protected:ro

worker_processes auto;

events {
    worker_connections 1024;
}

http {
    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;

    keepalive_timeout 65;
    keepalive_requests 1000;

    client_max_body_size 256k;
    client_header_timeout 15s;
    client_body_timeout 15s;
    send_timeout 60s;

    server_tokens off;

    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 5;
    gzip_min_length 1024;
    gzip_types
        text/plain
        text/css
        text/javascript
        application/javascript
        application/json
        image/svg+xml;

    # Caddy is the only trusted upstream proxy.
    # Must match TRUSTED_PROXY_CIDRS used by Uvicorn/FastAPI.
    set_real_ip_from 172.30.20.0/24;
    real_ip_header X-Forwarded-For;
    real_ip_recursive on;

    # Limits by real client IP.
    limit_req_zone $binary_remote_addr zone=general_limit:10m rate=20r/s;
    limit_req_zone $binary_remote_addr zone=search_limit:10m rate=2r/s;
    limit_req_zone $binary_remote_addr zone=audio_limit:10m rate=3r/s;
    limit_conn_zone $binary_remote_addr zone=per_ip_conn:10m;

    upstream fastapi {
        server s1ne:8003;
        keepalive 32;
    }

    server {
        listen 80;
        server_name _;

        root /usr/share/nginx/html;
        index index.html;
        autoindex off;

        add_header X-Content-Type-Options "nosniff" always;
        add_header X-Frame-Options "DENY" always;
        add_header Referrer-Policy "strict-origin-when-cross-origin" always;
        add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;

        limit_conn per_ip_conn 20;

        # Block accidental secret/source exposure from the public static mount.
        location ~ /\.(?!well-known) {
            deny all;
            access_log off;
            log_not_found off;
        }

        location ~* \.(?:bak|conf|dist|fla|in[ci]|log|orig|psd|sh|sql|swp|tmp)$ {
            deny all;
            access_log off;
            log_not_found off;
        }

        # Public SPA entry page.
        location = / {
            try_files /index.html =404;
            add_header Cache-Control "no-cache" always;
        }

        # Public static assets.
        # /static/app.js -> /usr/share/nginx/html/app.js
        location ^~ /static/ {
            alias /usr/share/nginx/html/;
            access_log off;

            expires 1h;
            add_header Cache-Control "public, max-age=3600" always;
        }

        # Long-cache versioned JavaScript asset.
        location = /static/app--3.js {
            alias /usr/share/nginx/html/app--3.js;
            access_log off;

            expires 30d;
            add_header Cache-Control "public, max-age=2592000, immutable" always;
        }

        # Optional public robots file.
        location = /robots.txt {
            try_files /robots.txt =404;
            default_type text/plain;
            add_header Cache-Control "public, max-age=86400" always;
        }

        # Protected files from a separate mounted directory.
        #
        # URL:       /files/report.pdf
        # Container: /protected/report.pdf
        location = /files {
            return 301 /files/;
        }

        location ^~ /files/ {
            auth_basic "Private media";
            auth_basic_user_file /etc/nginx/.htpasswd;

            alias /protected/;
            autoindex off;
        }

        # FastAPI validates share-token syntax and returns SPA documents.
        location ^~ /share/ {
            proxy_pass http://fastapi;
            proxy_http_version 1.1;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $realip_remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;

            proxy_connect_timeout 10s;
            proxy_read_timeout 60s;
            proxy_send_timeout 60s;
        }

        # Expensive yt-dlp endpoints.
        location ~ ^/api/(search|recommendations)$ {
            limit_req zone=search_limit burst=15 nodelay;
            limit_req_status 429;

            proxy_pass http://fastapi;
            proxy_http_version 1.1;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $realip_remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;

            proxy_connect_timeout 10s;
            proxy_read_timeout 120s;
            proxy_send_timeout 60s;
        }

        # Audio streaming, preserving Range/seek support.
        location ^~ /media/ {
            limit_req zone=audio_limit burst=30 nodelay;
            limit_req_status 429;

            proxy_pass http://fastapi;
            proxy_http_version 1.1;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $realip_remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;
            proxy_set_header Range $http_range;
            proxy_set_header If-Range $http_if_range;

            proxy_buffering off;
            proxy_request_buffering off;

            proxy_connect_timeout 10s;
            proxy_read_timeout 3600s;
            proxy_send_timeout 3600s;
            send_timeout 3600s;
        }

        # Audio download streaming.
        location ^~ /api/download/ {
            limit_req zone=audio_limit burst=20 nodelay;
            limit_req_status 429;

            proxy_pass http://fastapi;
            proxy_http_version 1.1;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $realip_remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;
            proxy_set_header Range $http_range;
            proxy_set_header If-Range $http_if_range;

            proxy_buffering off;
            proxy_request_buffering off;

            proxy_connect_timeout 10s;
            proxy_read_timeout 3600s;
            proxy_send_timeout 3600s;
            send_timeout 3600s;
        }

        # FastAPI health endpoints.
        location = /healthz {
            access_log off;

            proxy_pass http://fastapi/healthz;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $realip_remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;

            proxy_connect_timeout 5s;
            proxy_read_timeout 15s;
        }

        location = /readyz {
            access_log off;

            proxy_pass http://fastapi/readyz;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $realip_remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;

            proxy_connect_timeout 5s;
            proxy_read_timeout 15s;
        }

        # Remaining FastAPI endpoints.
        location /api/ {
            limit_req zone=general_limit burst=60 nodelay;
            limit_req_status 429;

            proxy_pass http://fastapi;
            proxy_http_version 1.1;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $realip_remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;

            proxy_connect_timeout 10s;
            proxy_read_timeout 120s;
            proxy_send_timeout 120s;
        }

        # Default deny: only explicitly configured paths are exposed.
        location / {
            return 404;
        }
    }
}