# =========================================================================
# Strangler routing: Django (holy-backend) and Rust (holy-rust) run side by
# side, sharing one SQLite DB + media dir + SECRET_KEY. Every endpoint group
# below can be served by EITHER backend, so cutover is per-group and instant:
# change a `proxy_pass` target, then `docker exec holy-frontend nginx -s reload`
# (or recreate the container). Rollback is the same edit in reverse.
#
# Cutover order (see backend-rs/README.md):
#   Phase 1  reads      -> categories, flavors, banners
#   Phase 2  auth+write  -> auth/token, ratings, replies, users, notifications, tickets
#   Phase 3  admin+jobs  -> admin-custom  (THEN stop Django beat + set
#                           RUST_ENABLE_SCHEDULER=true so exactly one scheduler runs)
#   Phase 4  retire      -> point catch-all /api/ at rust; serve /media/ from
#                           nginx; drop Django /admin/ + /static/ if unused.
# =========================================================================

upstream django_backend {
    server holy-backend:8000;
}

upstream rust_backend {
    server holy-rust:8001;
}

server {
    listen 80;

    # --- SPA -------------------------------------------------------------
    location / {
        root /usr/share/nginx/html;
        index index.html index.htm;
        try_files $uri $uri/ /index.html;
    }

    # --- API: per-group strangler routing --------------------------------
    # Longest-prefix match wins, so these specific groups override the
    # catch-all /api/ below. To cut a group over, swap django_backend ->
    # rust_backend on its proxy_pass line.

    # Phase 1 — read-only (safe to move first):
    location /api/categories/ { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }
    location /api/flavors/    { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }
    location /api/banners/    { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }

    # Phase 2 — auth + writes:
    location /api/auth/          { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }
    location = /api/token/       { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }  # legacy JWT alias
    location /api/ratings/       { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }
    location /api/replies/       { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }
    location /api/users/         { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }
    location /api/notifications/ { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }
    location /api/tickets/       { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }

    # Phase 3 — admin + jobs (cut over, THEN flip the scheduler ownership):
    location /api/admin-custom/  { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }

    # OpenAPI schema / Swagger UI (both backends serve these):
    location /api/schema { proxy_pass http://django_backend; include /etc/nginx/proxy_params.conf; }

    # Catch-all: anything not explicitly cut over stays on Django.
    location /api/ {
        proxy_pass http://django_backend;
        include /etc/nginx/proxy_params.conf;
    }

    # --- Django-only paths (retire last) ---------------------------------
    # Django admin site + its static assets. The app's own admin UI uses
    # /api/admin-custom/, so these are only the Django admin site + DRF UI.
    location /admin/ {
        proxy_pass http://django_backend;
        include /etc/nginx/proxy_params.conf;
    }
    location /static/ {
        proxy_pass http://django_backend;
        include /etc/nginx/proxy_params.conf;
    }

    # --- Media -----------------------------------------------------------
    # Served straight from the shared bind mount (read-only) so media does not
    # depend on either backend being up — a prerequisite for retiring Django.
    location /media/ {
        alias /usr/share/nginx/media/;
        access_log off;
        expires 7d;
        add_header Cache-Control "public";
        try_files $uri =404;
    }
}