{ pkgs, ... }:

let
  # Nix store paths are world-readable, so accounts.conf (IMAP/SMTP passwords)
  # stays hand-managed in ~/.config/aerc and out of this module.
  opener = if pkgs.stdenv.isDarwin then "open" else "xdg-open";

  # Renders the markdown body of a composed mail into the text/html half of a
  # multipart/alternative message (see [multipart-converters] below).
  mdToHtml = pkgs.writeShellScriptBin "aerc-md2html" ''
    body=$(${pkgs.cmark-gfm}/bin/cmark-gfm \
      --extension autolink \
      --extension table \
      --extension strikethrough \
      --extension tasklist)

    cat <<HTML
    <!DOCTYPE html>
    <html>
    <head>
    <meta charset="utf-8">
    <meta name="color-scheme" content="light dark">
    <style>
    body { font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
           font-size: 15px; line-height: 1.5; color: #1a1a1a; background: #ffffff;
           max-width: 40em; margin: 0; padding: 0; }
    a { color: #2b5cd9; }
    h1, h2, h3 { line-height: 1.25; margin: 1.2em 0 0.5em; }
    h1 { font-size: 1.4em; }
    h2 { font-size: 1.2em; }
    h3 { font-size: 1.05em; }
    p, ul, ol, table { margin: 0 0 1em; }
    blockquote { margin: 0 0 1em; padding: 0 0 0 1em; border-left: 3px solid #d0d0d0; color: #555; }
    code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.9em; }
    code { background: #f2f2f2; padding: 0.1em 0.3em; border-radius: 3px; }
    pre { background: #f2f2f2; padding: 0.8em; border-radius: 4px; overflow-x: auto; }
    pre code { background: none; padding: 0; }
    table { border-collapse: collapse; }
    th, td { border: 1px solid #d0d0d0; padding: 0.3em 0.6em; text-align: left; }
    hr { border: none; border-top: 1px solid #d0d0d0; margin: 1.5em 0; }
    @media (prefers-color-scheme: dark) {
      body { color: #e6e6e6; background: #1a1a1a; }
      a { color: #7aa2f7; }
      blockquote { border-left-color: #444; color: #aaa; }
      code, pre { background: #262626; }
      th, td, hr { border-color: #444; }
    }
    </style>
    </head>
    <body>
    $body
    </body>
    </html>
    HTML
  '';

  notify =
    if pkgs.stdenv.isDarwin then
      # -activate focuses Ghostty when the banner is clicked.
      "${pkgs.terminal-notifier}/bin/terminal-notifier"
      + " -group \"aerc-$AERC_ACCOUNT\""
      + " -title \"$AERC_ACCOUNT/$AERC_FOLDER\""
      + " -subtitle \"$AERC_FROM_NAME\""
      + " -message \"$AERC_SUBJECT\""
      + " -activate com.mitchellh.ghostty"
    else
      "${pkgs.libnotify}/bin/notify-send"
      + " \"[$AERC_ACCOUNT/$AERC_FOLDER] $AERC_FROM_NAME\""
      + " \"$AERC_SUBJECT\"";
in
{
  home.file = {
    ".config/aerc/aerc.conf".text = ''
      [general]
      default-save-path=~/Downloads
      pgp-provider=auto
      default-menu-cmd=fzf --reverse --prompt='> '

      [ui]
      styleset-name=tokyonight
      mouse-enabled=true
      threading-enabled=true
      fuzzy-complete=true
      keyhint=true
      keyhint-delay=300ms
      sidebar-width=24
      index-columns=flags:4,name<20%,subject,date>=
      timestamp-format=2006-01-02 15:04
      this-day-time-format=15:04
      this-week-time-format=Mon 15:04
      this-year-time-format=02 Jan
      empty-message=(no messages)
      empty-dirlist=(no folders)

      [statusline]
      column-left=[{{.Account}}] {{.StatusInfo}}
      column-center={{.PendingKeys}}
      column-right={{.TrayInfo}}

      [viewer]
      pager=less -Rc
      alternatives=text/plain,text/html
      show-headers=false
      header-layout=From|To,Cc|Bcc,Date,Subject
      parse-http-links=true

      [compose]
      editor=nvim -c 'set ft=mail' -c 'set textwidth=72' -c 'set nolist'
      header-layout=To|From,Subject
      focus-body=true
      empty-subject-warning=true
      no-attachment-warning=^[^>]*attach(ed|ment)

      [multipart-converters]
      text/html=${mdToHtml}/bin/aerc-md2html

      [hooks]
      mail-received=${notify}

      [filters]
      text/plain=colorize
      text/calendar=calendar
      message/delivery-status=colorize
      message/rfc822=colorize
      text/html=! html
      .headers=colorize

      [openers]
      x-scheme-handler/http*=${opener} {}
      x-scheme-handler/mailto=${opener} {}
      text/html=${opener} {}
      application/pdf=${opener} {}
      image/*=${opener} {}
    '';

    ".config/aerc/binds.conf".text = ''
      # Part/field navigation is bound twice: C-j/C-k as aerc ships them, plus
      # ]p/[p and Alt-j/Alt-k (right Option = Alt, see modules/home/ghostty.nix)
      # which keep working if vim-tmux-navigator's tmux side is ever installed,
      # since it claims C-h/j/k/l for any pane that is not running vim.

      <C-p> = :prev-tab<Enter>
      <C-n> = :next-tab<Enter>
      \[t = :prev-tab<Enter> # Previous tab
      \]t = :next-tab<Enter> # Next tab
      <C-t> = :term<Enter>
      ? = :help keys<Enter>
      <C-q> = :prompt 'Quit?' quit<Enter>
      <C-z> = :suspend<Enter>

      [messages]
      q = :prompt 'Quit?' quit<Enter>
      . = :repeat

      j = :next<Enter>
      <Down> = :next<Enter>
      k = :prev<Enter>
      <Up> = :prev<Enter>
      <C-d> = :next 50%<Enter>
      <C-u> = :prev 50%<Enter>
      <C-f> = :next 100%<Enter>
      <C-b> = :prev 100%<Enter>
      <PgDn> = :next 100%<Enter>
      <PgUp> = :prev 100%<Enter>
      gg = :select 0<Enter> # First message
      G = :select -1<Enter>
      zz = :align center<Enter>
      zt = :align top<Enter>
      zb = :align bottom<Enter>

      J = :next-folder<Enter>
      K = :prev-folder<Enter>
      gi = :cf INBOX<Enter> # Inbox
      ga = :cf Archive<Enter> # Archive
      gd = :cf Drafts<Enter> # Drafts
      gs = :cf Sent<Enter> # Sent
      gj = :cf Junk<Enter> # Junk
      gt = :cf Trash<Enter> # Trash
      gf = :menu -dc fzf :cf<Enter> # Find folder (fzf)
      c = :cf<space>

      <Enter> = :view<Enter>
      v = :mark -t<Enter>
      <Space> = :mark -t<Enter>:next<Enter>
      V = :mark -v<Enter>
      tt = :toggle-threads<Enter> # Threads
      ts = :toggle-sidebar<Enter> # Sidebar
      tf = :toggle-folder<Enter> # Folder subscription
      tc = :toggle-thread-context<Enter> # Thread context
      zc = :fold<Enter>
      zo = :unfold<Enter>
      za = :fold -t<Enter>
      zM = :fold -a<Enter>
      zR = :unfold -a<Enter>
      <tab> = :fold -t<Enter>

      C = :compose<Enter>
      r = :reply -aq<Enter>
      R = :reply -q<Enter>
      f = :forward<Enter>
      b = :bounce<space>
      d = :choose -o y 'Really delete this message' delete-message<Enter>
      D = :delete<Enter>
      a = :archive flat<Enter>
      A = :unmark -a<Enter>:mark -T<Enter>:archive flat<Enter>
      M = :move<space>
      mm = :move<space> # Move to folder
      mc = :copy<space> # Copy to folder
      mr = :read<Enter> # Mark read
      mu = :unread<Enter> # Mark unread
      mf = :flag -t -x flagged<Enter> # Toggle flagged
      mU = :unsubscribe<Enter> # Unsubscribe from list
      s = :split<Enter>
      S = :vsplit<Enter>
      | = :pipe<space>
      $ = :term<space>

      / = :search<space>
      \ = :filter<space>
      n = :next-result<Enter>
      N = :prev-result<Enter>
      <Esc> = :clear<Enter>
      <C-c> = :clear<Enter>
      Fu = :filter -u<Enter> # Unread
      Ff = :filter -x flagged<Enter> # Flagged
      Fs = :filter -f<space> # From sender
      Ft = :filter -t<space> # To recipient
      Fd = :filter -d<space> # Date range
      Fc = :clear<Enter> # Clear filter
      F/ = :filter<space> # Filter prompt

      [messages:folder=Drafts]
      <Enter> = :recall<Enter>

      [view]
      # The viewer forwards every key it does not bind itself to the pager, so
      # globals like ? and : never arrive: bind them again here.
      $ex = :
      ? = :help keys<Enter>
      / = :toggle-key-passthrough<Enter>/
      q = :close<Enter>
      <Esc> = :close<Enter>
      o = :open<Enter>
      O = :open<space>
      S = :save<space>
      s = :save -fpa ~/Downloads<Enter>
      | = :pipe<space>
      d = :choose -o y 'Really delete this message' delete-message<Enter>
      D = :delete<Enter>
      a = :archive flat<Enter>
      f = :forward<Enter>
      r = :reply -aq<Enter>
      R = :reply -q<Enter>
      H = :toggle-headers<Enter>
      th = :toggle-headers<Enter> # Headers
      <C-j> = :next-part<Enter>
      <C-Down> = :next-part<Enter>
      <C-k> = :prev-part<Enter>
      <C-Up> = :prev-part<Enter>
      \]p = :next-part<Enter> # Next part
      \[p = :prev-part<Enter> # Previous part
      \]m = :next<Enter> # Next message
      \[m = :prev<Enter> # Previous message
      J = :next<Enter>
      K = :prev<Enter>
      gx = :menu -lc fzf :open-link<Enter> # Open link (fzf)
      gy = :copy-link<space>

      [view::passthrough]
      $noinherit = true
      $ex = <C-x>
      <Esc> = :toggle-key-passthrough<Enter>

      [compose]
      $noinherit = true
      $ex = <C-x>
      $complete = <C-o>
      <tab> = :next-field<Enter>
      <backtab> = :prev-field<Enter>
      <C-j> = :next-field<Enter>
      <C-Down> = :next-field<Enter>
      <C-k> = :prev-field<Enter>
      <C-Up> = :prev-field<Enter>
      <A-j> = :next-field<Enter>
      <A-k> = :prev-field<Enter>
      <A-p> = :switch-account -p<Enter>
      <A-n> = :switch-account -n<Enter>
      <C-p> = :prev-tab<Enter>
      <C-n> = :next-tab<Enter>

      [compose::editor]
      $noinherit = true
      $ex = <C-x>
      <C-j> = :next-field<Enter>
      <C-Down> = :next-field<Enter>
      <C-k> = :prev-field<Enter>
      <C-Up> = :prev-field<Enter>
      <A-j> = :next-field<Enter>
      <A-k> = :prev-field<Enter>
      <C-p> = :prev-tab<Enter>
      <C-n> = :next-tab<Enter>

      [compose::review]
      # aerc has no "always send HTML" setting, so the send key adds the
      # text/html alternative first; Y sends the plain text part on its own.
      y = :multipart text/html<Enter>:send<Enter> # Send (HTML + plain text)
      Y = :send<Enter> # Send plain text only
      h = :multipart text/html<Enter> # Add HTML alternative
      H = :multipart -d text/html<Enter> # Drop HTML alternative
      n = :abort<Enter> # Abort (discard message, no confirmation)
      s = :sign<Enter> # Toggle signing
      x = :encrypt<Enter> # Toggle encryption to all recipients
      v = :preview<Enter> # Preview message
      p = :postpone<Enter> # Postpone
      q = :choose -o d discard abort -o p postpone postpone<Enter> # Abort or postpone
      e = :edit<Enter> # Edit (body and headers)
      a = :attach<space> # Add attachment
      A = :menu -c 'fzf --multi' :attach<Enter> # Add attachment (fzf)
      d = :detach<space> # Remove attachment

      [terminal]
      $noinherit = true
      $ex = <C-x>
      <C-p> = :prev-tab<Enter>
      <C-n> = :next-tab<Enter>
    '';

    # tokyonight-storm, matching Ghostty (modules/home/ghostty.nix). Background
    # is left at the terminal default so the panes blend with the window.
    ".config/aerc/stylesets/tokyonight".text = ''
      *.default=true
      *.normal=true

      default.fg=#c0caf5

      error.fg=#f7768e
      warning.fg=#ff9e64
      success.fg=#9ece6a

      title.fg=#1f2335
      title.bg=#7aa2f7
      title.bold=true
      header.fg=#7aa2f7
      header.bold=true
      realname.fg=#c0caf5
      email.fg=#565f89
      subject.fg=#c0caf5
      subject.bold=true
      date.fg=#565f89

      tab.fg=#545c7e
      tab.bg=#1f2335
      tab.selected.fg=#c0caf5
      tab.selected.bg=#292e42
      tab.selected.bold=true

      border.fg=#292e42
      border.bg=#292e42

      spinner.fg=#7dcfff

      msglist_default.fg=#a9b1d6
      msglist_unread.fg=#c0caf5
      msglist_unread.bold=true
      msglist_read.fg=#737aa2
      msglist_answered.fg=#bb9af7
      msglist_forwarded.fg=#9d7cd8
      msglist_flagged.fg=#e0af68
      msglist_flagged.bold=true
      msglist_deleted.fg=#565f89
      msglist_deleted.dim=true
      msglist_result.fg=#9ece6a
      msglist_result.bold=true
      msglist_thread_folded.fg=#7dcfff
      msglist_thread_context.fg=#565f89
      msglist_thread_orphan.fg=#ff9e64
      msglist_marked.fg=#1f2335
      msglist_marked.bg=#7dcfff
      msglist_gutter.fg=#292e42
      msglist_pill.fg=#1f2335
      msglist_pill.bg=#7aa2f7
      msglist_*.selected.bg=#292e42
      msglist_*.selected.bold=true

      dirlist_default.fg=#a9b1d6
      dirlist_unread.fg=#7aa2f7
      dirlist_unread.bold=true
      dirlist_recent.fg=#7dcfff
      dirlist_*.selected.bg=#292e42
      dirlist_*.selected.bold=true

      statusline_default.fg=#c0caf5
      statusline_default.bg=#1f2335
      statusline_error.fg=#f7768e
      statusline_error.bold=true
      statusline_warning.fg=#ff9e64
      statusline_success.fg=#9ece6a
      statusline_success.bold=true

      completion_default.fg=#a9b1d6
      completion_default.selected.bg=#292e42
      completion_description.fg=#565f89
      completion_gutter.bg=#1f2335
      completion_pill.bg=#7aa2f7

      keyhint_default.bg=#1f2335
      keyhint_key.fg=#7dcfff
      keyhint_key.bold=true
      keyhint_desc.fg=#a9b1d6

      part_switcher.bg=#1f2335
      part_filename.fg=#7dcfff
      part_mimetype.fg=#565f89
      part_*.selected.bg=#292e42

      selector_default.fg=#a9b1d6
      selector_focused.fg=#c0caf5
      selector_focused.bg=#292e42
      selector_chooser.bold=true

      [viewer]
      url.fg=#7dcfff
      url.underline=true
      header.fg=#7aa2f7
      header.bold=true
      signature.fg=#565f89
      signature.dim=true
      diff_meta.fg=#c0caf5
      diff_meta.bold=true
      diff_chunk.fg=#7dcfff
      diff_chunk_func.fg=#7dcfff
      diff_chunk_func.bold=true
      diff_add.fg=#9ece6a
      diff_del.fg=#f7768e
      diff_whitespace.bg=#f7768e
      quote_1.fg=#7aa2f7
      quote_2.fg=#bb9af7
      quote_3.fg=#7dcfff
      quote_4.fg=#565f89
      quote_x.fg=#565f89
      quote_x.dim=true
      code.fg=#9ece6a
    '';
  };
}