# Copyright 2020 the .NET Foundation
# Licensed under the MIT License
#
# Useful links:
#
# https://nginx.org/en/docs/http/ngx_http_core_module.html#variables
# https://nginx.org/en/docs/http/ngx_http_map_module.html
# https://nginx.org/en/docs/http/ngx_http_rewrite_module.html#rewrite

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
  worker_connections 1024;
}

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

  log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';
  access_log /var/log/nginx/access.log main;

  sendfile on;
  #tcp_nopush on;
  keepalive_timeout 65;
  #gzip on;

  map_hash_bucket_size 128;

  map $uri $rw_temp_path {
    default "none";
    include /etc/nginx/temporary_redirects.map;
  }

  map $uri $rw_perm_path {
    default "none";
    include /etc/nginx/permanent_redirects.map;
  }

  server {
    listen 80;
    root /usr/share/nginx/html;

    # Set up to redirect properly. See the README for a bit on the motivation
    # -- we need to handle several combinations to support both local Docker
    # testing and production deployment behind an SSL terminating gateway.
    # Note that (1) environment variables are substituted into this file
    # literally using `envsubst` (see `Dockerfile`) (2) nginx's `if` syntax is
    # very limited, disallowing nesting and comparison of literals.

    set $pfdn "${PUBLIC_FACING_DOMAIN_NAME}";
    set $redir_scheme $scheme;

    if ($http_x_forwarded_proto != "") {
      set $redir_scheme "$http_x_forwarded_proto";
    }

    set $redir_prefix "$redir_scheme://$http_host";

    if ($pfdn != "") {
      set $redir_prefix "$redir_scheme://$pfdn";
    }

    location = / {
      # We use a cookie named "homepage" to set where visitors to the
      # / path should be routed. In the ASP.NET server the value of
      # this cookie is just used as the redirect path, but we tighten
      # things up to only recognize the special case of "home".
      if ($cookie_homepage = "home") {
        rewrite ^ "$redir_prefix/home" redirect;
      }

      rewrite ^ "$redir_prefix/webclient/" redirect;
    }

    if ($rw_perm_path ~ "^http") {
      rewrite ^ "$rw_perm_path" permanent;
    }

    if ($rw_perm_path != "none") {
      rewrite ^ "$redir_prefix$rw_perm_path" permanent;
    }

    if ($rw_temp_path != "none") {
      rewrite ^ "$redir_prefix$rw_temp_path" redirect;
    }

    #error_page 404 /404.html;

    # redirect server error pages to the static page /50x.html
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }
  }
}