{ config, lib, ... }:

let
  cfg = config.services.matrix-synapse;
  dbGroup = "solo";
  workers = lib.range 0 (cfg.authWorkers - 1);
  workerName = "auth";
  workerRoutes = {
    client = [
      "~ ^/_matrix/client/(api/v1|r0|v3|unstable)/login$"
      "~ ^/_matrix/client/(api/v1|r0|v3|unstable)/account/3pid$"
      "~ ^/_matrix/client/(api/v1|r0|v3|unstable)/account/whoami$"
      "~ ^/_matrix/client/versions$"
      "~ ^/_matrix/client/(api/v1|r0|v3|unstable)/voip/turnServer$"
      "~ ^/_matrix/client/(r0|v3|unstable)/register$"
      "~ ^/_matrix/client/(r0|v3|unstable)/register/available$"
      "~ ^/_matrix/client/(r0|v3|unstable)/auth/.*/fallback/web$"
      "~ ^/_matrix/client/(r0|v3|unstable)/password_policy$"
      "~ ^/_matrix/client/(r0|v3|unstable)/capabilities$"
    ];
    federation = [ ];
    media = [ ];
  };
in
{
  config = lib.mkIf (cfg.authWorkers > 0) {
    services.matrix-synapse = {
      settings = {
        instance_map = lib.listToAttrs (
          lib.map (index: {
            name = "${workerName}-${toString index}";
            value = {
              path = "/run/matrix-synapse/${workerName}-${toString index}.sock";
            };
          }) workers
        );
      };

      workers = lib.listToAttrs (
        lib.map (index: {
          name = "${workerName}-${toString index}";
          value = {
            worker_app = "synapse.app.generic_worker";
            worker_listeners = [
              {
                type = "http";
                path = "/run/matrix-synapse/${workerName}-${toString index}.sock";
                resources = [
                  {
                    names = [ "replication" ];
                    compress = false;
                  }
                ];
              }
              {
                type = "http";
                path = "/run/matrix-synapse/${workerName}-client-${toString index}.sock";
                mode = "666";
                resources = [
                  {
                    names = [ "client" ];
                    compress = false;
                  }
                ];
              }
            ];
            database = (
              import ../db.nix {
                inherit dbGroup;
                workerName = "${workerName}-${toString index}";
              }
            );
          };
        }) workers
      );
    };

    services.nginx.upstreams = (
      lib.listToAttrs (
        lib.map (type: {
          name = "${workerName}-${type}";
          value = {
            extraConfig = ''
              keepalive 32;
            '';
            servers = lib.listToAttrs (
              lib.map (index: {
                name = "unix:/run/matrix-synapse/${workerName}-${type}-${toString index}.sock";
                value = {
                  max_fails = 0;
                };
              }) workers
            );
          };
        }) ([ ] ++ lib.optional (lib.length workerRoutes.client > 0) "client" ++ lib.optional (lib.length workerRoutes.federation > 0) "federation" ++ lib.optional (lib.length workerRoutes.media > 0) "media")
      )
    );

    services.nginx = {
      virtualHosts."${cfg.nginxVirtualHostName}".locations = lib.listToAttrs (
        lib.flatten (
          lib.forEach ([ ] ++ lib.optional (lib.length workerRoutes.client > 0) "client" ++ lib.optional (lib.length workerRoutes.federation > 0) "federation" ++ lib.optional (lib.length workerRoutes.media > 0) "media") (
            type:
            lib.map (route: {
              name = route;
              value = {
                proxyPass = "http://${workerName}-${type}";

              };
            }) workerRoutes.${type}
          )
        )
      );
    };
  };
}