# Mnemosyne nginx — single virtual host that fronts the Django web app
# and the FastMCP server. HAProxy on Titania terminates TLS and routes by
# hostname; this nginx is plain HTTP on the internal network.

# Suppress probe paths from the access log (health checks, Prometheus scrapes).
# These fire every 15–30 s and would drown out real traffic in Loki.
map $request_uri $loggable {
    default                     1;
    ~^/live(/|\?|$)             0;
    ~^/ready(/|\?|$)            0;
    ~^/metrics(/|\?|$)          0;
    ~^/healthz(/|\?|$)          0;
    ~^/health                   0;
    ~^/mcp/health(/|\?|$)       0;
    ~^/ping(/|\?|$)             0;
}

# Map of upstreams to give us readable proxy_pass targets and easy retries.
upstream mnemosyne_app {
    server app:8000 max_fails=3 fail_timeout=30s;
}

upstream mnemosyne_mcp {
    server mcp:8001 max_fails=3 fail_timeout=30s;
}

server {
    listen 80 default_server;
    server_name _;

    access_log /var/log/nginx/access.log combined if=$loggable;

    # Reasonable limits — file uploads to the ingest endpoint can be big,
    # but the bulk path is S3-direct from Daedalus. 64 MB covers admin
    # uploads and direct REST POST /library/api/items/upload.
    client_max_body_size 64m;
    client_body_timeout  120s;

    # Liveness probe — always 200 if the Django process is up.
    # Use the trailing-slash form: /live/ returns 200 directly.
    # /live (no slash) triggers Django's APPEND_SLASH 301 redirect, which
    # will cause health check clients that don't follow redirects to fail.
    location = /live/ {
        proxy_pass http://mnemosyne_app;
        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;
        access_log off;
    }

    # Readiness probe — 200 only when PostgreSQL + Memcached are reachable.
    # Same trailing-slash rule applies.
    location = /ready/ {
        proxy_pass http://mnemosyne_app;
        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;
        access_log off;
    }

    # HAProxy liveness probe — proxies through to the MCP health endpoint.
    location = /healthz {
        proxy_pass http://mnemosyne_mcp/mcp/health;
        access_log off;
    }

    # Mnemosyne's REST API — Django REST Framework views + admin.
    # Under /library/api/* per mnemosyne/urls.py and /admin/* per Django.
    location /library/ {
        proxy_pass http://mnemosyne_app;
        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_read_timeout 300s;
    }

    location /admin/ {
        proxy_pass http://mnemosyne_app;
        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_read_timeout 300s;
    }

    # FastMCP Streamable HTTP at /mcp/ and SSE at /mcp/sse/.
    # Long-running streams need disabled buffering and a generous timeout.
    location /mcp/ {
        proxy_pass http://mnemosyne_mcp;
        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 Connection        "";
        proxy_buffering    off;
        proxy_cache        off;
        proxy_read_timeout 600s;
    }

    # Static files baked into the image at /app/staticfiles, mounted into
    # this nginx via a named volume populated by the app service.
    location /static/ {
        alias /var/www/static/;
        access_log off;
        expires 30d;
    }

    # Prometheus scrape endpoint — internal networks only.
    # Allows: loopback + all RFC1918 private ranges.
    location /metrics {
        allow 127.0.0.0/8;
        allow 10.0.0.0/8;
        allow 172.16.0.0/12;
        allow 192.168.0.0/16;
        deny  all;
        proxy_pass http://mnemosyne_app;
        access_log off;
    }
}