map $http_x_forwarded_host $docroot_path {
    hostnames;
    default  /public/default;
    about.*  /public/about;
    blog.*   /public/blog;
    slides.* /public/slides;
}

map $http_x_forwarded_host $about_domain {
    hostnames;
    default          about.nsfisis.dev;
    *.localhost:8000 about.localhost:8000;
}

map $http_x_forwarded_host $blog_domain {
    hostnames;
    default          blog.nsfisis.dev;
    *.localhost:8000 blog.localhost:8000;
}

map $http_x_forwarded_host $slides_domain {
    hostnames;
    default          slides.nsfisis.dev;
    *.localhost:8000 slides.localhost:8000;
}

map $http_x_forwarded_host $is_about_domain {
    hostnames;
    default 0;
    about.* 1;
}

map $http_x_forwarded_host $is_blog_domain {
    hostnames;
    default 0;
    blog.*  1;
}

map $http_x_forwarded_host $is_slides_domain {
    hostnames;
    default  0;
    slides.* 1;
}

server {
    listen 80 default;
    listen [::]:80;

    location / {
        root $docroot_path;

        location ~* ^.*/atom\.xml$ {
            types { }
            default_type "application/atom+xml; charset=utf-8";
        }

        location ~* \.mjs$ {
            types { }
            default_type "application/javascript; charset=utf-8";
        }

        location ~* \.md$ {
            types { }
            default_type "text/markdown; charset=utf-8";
        }
    }

    error_page 404 /404.html;

    # Redirect to canonical path.
    rewrite ^/posts/1/?$  /posts/  permanent;
    rewrite ^/slides/1/?$ /slides/ permanent;

    # Redirect to posts/slides pages.
    if ($is_blog_domain) {
        rewrite ^/?$ $http_x_forwarded_proto://$blog_domain/posts/ permanent;
    }
    if ($is_slides_domain) {
        rewrite ^/?$ $http_x_forwarded_proto://$slides_domain/slides/ permanent;
    }

    if ($is_blog_domain) {
        # Old URL patterns.
        rewrite ^/posts/(my-first-post)/?$                                           $http_x_forwarded_proto://$blog_domain/posts/2021-03-05/$1/ permanent;
        rewrite ^/posts/(phperkaigi-2021)/?$                                         $http_x_forwarded_proto://$blog_domain/posts/2021-03-30/$1/ permanent;
        rewrite ^/posts/(cpp-you-can-use-keywords-in-attributes)/?$                  $http_x_forwarded_proto://$blog_domain/posts/2021-10-02/$1/ permanent;
        rewrite ^/posts/(python-unbound-local-error)/?$                              $http_x_forwarded_proto://$blog_domain/posts/2021-10-02/$1/ permanent;
        rewrite ^/posts/(ruby-detect-running-implementation)/?$                      $http_x_forwarded_proto://$blog_domain/posts/2021-10-02/$1/ permanent;
        rewrite ^/posts/(ruby-then-keyword-and-case-in)/?$                           $http_x_forwarded_proto://$blog_domain/posts/2021-10-02/$1/ permanent;
        rewrite ^/posts/(rust-where-are-primitive-types-from)/?$                     $http_x_forwarded_proto://$blog_domain/posts/2021-10-02/$1/ permanent;
        rewrite ^/posts/(vim-difference-between-autocmd-bufwrite-and-bufwritepre)/?$ $http_x_forwarded_proto://$blog_domain/posts/2021-10-02/$1/ permanent;
        rewrite ^/posts/(vim-swap-order-of-selected-lines)/?$                        $http_x_forwarded_proto://$blog_domain/posts/2021-10-02/$1/ permanent;
        rewrite ^/posts/(phperkaigi-2022-tokens)/?$                                  $http_x_forwarded_proto://$blog_domain/posts/2022-04-09/$1/ permanent;

        # I mistakenly wrote 2023 in the URL instead of 2024.
        rewrite ^/posts/2023-01-10/(neovim-insert-namespace-declaration-to-empty-php-file)/?$ $http_x_forwarded_proto://$blog_domain/posts/2024-01-10/$1/ permanent;

        # Renamed posts.
        rewrite ^/posts/2024-03-20/todos-in-my-life/?$ $http_x_forwarded_proto://$blog_domain/posts/2024-03-20/my-bucket-list/ permanent;
    }

    # Redirect to new domains.
    if ($is_about_domain = 0) {
        rewrite ^/about/?$ $http_x_forwarded_proto://$about_domain/ permanent;
    }
    if ($is_blog_domain = 0) {
        rewrite ^/posts(/.*)/?$ $http_x_forwarded_proto://$blog_domain/posts$1/ permanent;
    }
    if ($is_slides_domain = 0) {
        rewrite ^/slides(/.*)/?$ $http_x_forwarded_proto://$slides_domain/slides$1/ permanent;
    }
}