# alot config loader is sensitive to leading space !
{ config, lib, pkgs, ... }:

with lib;

let

  cfg = config.programs.alot;

  dag = config.lib.dag;

  alotAccounts = filter (a: a.alot.enable)
    (attrValues config.accounts.email.accounts);

  contactCompletionStr = account:
    ''
  [[[abook]]]
  type = shellcommand
  command = '' + (
  if (account.alot.contactCompletionCommand != null) then 
      account.alot.contactCompletionCommand
  else config.programs.notmuch.contactCompletion);

  sendMailCommand = account:
    if account.alot.sendMailCommand != null then account.alot.sendMailCommand
    else if account.msmtp.enable then config.programs.msmtp.sendCommand account else "";

accountStr = account: with account;
    ''
      [[${name}]]
      address = ${address}
      realname = ${realName}
      sendmail_command = ${sendMailCommand account}

      # contact completion
      ${contactCompletionStr account}
    '';

  configFile = mailAccounts: let
    bindingsToStr = attrSet: concatStringsSep "\n" (mapAttrsToList (n: v: "${n} = ${v}") attrSet);
  in ''
# Generated by home-manager
# see http://alot.readthedocs.io/en/latest/configuration/config_options.html
hooksfile = "''${XDG_CONFIG_HOME:-$HOME/.config}/alot/hm_hooks"
${cfg.extraConfig}

[bindings]
${bindingsToStr cfg.bindings.global}

[[bufferlist]]
${bindingsToStr cfg.bindings.bufferlist}
[[search]]
${bindingsToStr cfg.bindings.search}
[[envelope]]
${bindingsToStr cfg.bindings.envelope}
[[taglist]]
${bindingsToStr cfg.bindings.taglist}
[[thread]]
${bindingsToStr cfg.bindings.thread}

[accounts]

${concatStringsSep "\n" (map accountStr mailAccounts)}
'';

in
{

  options = {
    programs.alot = {
      enable = mkEnableOption "Alot";

      extraHookFile = mkOption {
        type = types.lines;
        default = "";
        description = ''
          Content to append to the hooks file (after home-manager python code).
        '';
      };

      bindings = mkOption {

        type = types.submodule {
          options = {
            global = mkOption {
              type = types.attrsOf types.str;
              default = {};
              description = "Global keybindings.";
            };
            bufferlist = mkOption {
              type = types.attrsOf types.str;
              default = {};
              description = "Bufferlist mode keybindings.";
            };
            search = mkOption {
              type = types.attrsOf types.str;
              default = {};
              description = "Search mode keybindings.";
            };
            envelope = mkOption {
              type = types.attrsOf types.str;
              default = {};
              description = "Envelope mode keybindings.";
            };
            taglist = mkOption {
              type = types.attrsOf types.str;
              default = {};
              description = "Taglist mode keybindings.";
            };
            thread = mkOption {
              type = types.attrsOf types.str;
              default = {};
              description = "Thread mode keybindings.";
            };
          };
        };
        default = {};
        description = ''
          Bindings.
        '';
      };

      extraConfig = mkOption {
        type = types.lines;
        default = ''
          auto_remove_unread = True
          ask_subject = False
          handle_mouse = True
          initial_command = "search tag:inbox AND NOT tag:killed"
          input_timeout = 0.3
          prefer_plaintext = True
          thread_indent_replies = 4
        '';
        description = ''
          Extra lines added to alot configuration file.
        '';
      };
    };

    accounts.email.accounts = mkOption {
      options = [ {
          alot = {
            enable = mkEnableOption "alot";

            contactCompletionCommand = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = ''
                Command to run to send a message.
                See <link xlink:href="https://alot.readthedocs.io/en/latest/configuration/contacts_completion.html" /> for more advice.
                '';
            };

            sendMailCommand = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = ''
                Command to send a mail.
              '';
            };
          };
      } ];
    };
  };

  config = mkIf cfg.enable {

    home.packages =  [ pkgs.alot ];

    xdg.configFile."alot/config".text =
      configFile alotAccounts;

    xdg.configFile."alot/hm_hooks".text = ''
      # Home-manager custom hooks
    '' + cfg.extraHookFile;
  };
}