type head_data = { page_title : string }

type body_data = {
  title : string;
  subtitle : string;
  content : Dream_html.node list;
}

module Components = struct
  open Dream_html

  let topnav current_path =
    let open HTML in
    let li_of_a (path, text) =
      let is_active = path = current_path in
      let attrs = if is_active then [ id "active" ] else [] in
      let url =
        if String.equal path "/" then Printf.sprintf "/%s/" current_path
        else Printf.sprintf "/%s/%s" current_path path
      in
      li attrs [ a [ href "%s" url ] [ txt text ] ]
    in
    nav
      [ id "top" ]
      [
        ul []
        @@ List.map li_of_a
             [
               ("/", "summary");
               ("refs/", "refs");
               ("log/", "log");
               ("tree/", "tree");
               ("commit/", "commit");
             ];
      ]
end

module Page = struct
  open Dream_html
  open HTML

  let header title subtitle =
    null [ h1 [] [ txt "%s" title ]; h2 [] [ txt "%s" subtitle ] ]

  let footer () =
    let today = Unix.localtime (Unix.time ()) in
    let year = string_of_int (today.Unix.tm_year + 1900) in
    let footer_text = Printf.sprintf "Copyright %s %s" year Config.author in
    footer [] [ txt "%s" footer_text ]

  let default_head_data = { page_title = "Ogit" }

  let render ?(head_data = default_head_data) body_data =
    html []
      [
        head []
          [
            title [] "%s" head_data.page_title;
            link [ rel "stylesheet"; href "/static/styles.css" ];
            link
              [ rel "icon"; type_ "image/x-icon"; href "/static/git_icon.svg" ];
          ];
        body []
          [
            header body_data.title body_data.subtitle;
            Components.topnav body_data.title;
            div [ id "main" ] body_data.content;
            footer ();
          ];
      ]
end

let root () =
  let open Dream_html in
  let repositories_in directory =
    let repos =
      Sys.readdir directory |> Array.to_list |> List.sort String.compare
    in
    let li_of_repo repo =
      HTML.(li [] [ a [ href "%s/" repo ] [ txt "%s" repo ] ])
    in
    HTML.(div [ id "repositories" ] [ ul [] @@ List.map li_of_repo repos ])
  in
  let body_data =
    {
      title = "Ogit";
      subtitle = "Repositories for " ^ Config.author;
      content = [ repositories_in Config.git_directory ];
    }
  in
  Page.render body_data

module Repo = struct
  let summary repo_path branches commits authors =
    let open Dream_html in
    let li_of_branch branch =
      HTML.(li [] [ a [ href "%s" branch ] [ txt "%s" branch ] ])
    in
    let li_of_commit (commit : Git_helpers.Commit.t) =
      match commit.message with
      | Some msg ->
          HTML.(
            li []
              [
                a
                  [ href "commit/?id=%s" commit.hash ]
                  [ txt "%s %s" (Git_helpers.short_hash commit.hash) msg ];
              ])
      | None -> HTML.(li [] [ a [ href "" ] [ txt "caca!!" ] ])
    in
    let li_of_author author =
      HTML.(li [] [ a [ href "" ] [ txt "%s" author ] ])
    in
    let content =
      HTML.
        [
          h3 [] [ txt "Branches" ];
          ul [] (List.map li_of_branch branches);
          h3 [] [ txt "Recent commits" ];
          ul [] (List.map li_of_commit commits);
          h3 [] [ txt "Authors" ];
          ul [] (List.map li_of_author authors);
        ]
    in
    Page.render
      {
        title = repo_path;
        subtitle = Git_helpers.repo_description repo_path;
        content;
      }

  let refs repo_path =
    let open Dream_html in
    Page.render
      HTML.
        {
          title = repo_path;
          subtitle = Git_helpers.repo_description repo_path;
          content = [ null [] ];
        }

  let log repo_path =
    let open Dream_html in
    Page.render
      HTML.
        {
          title = repo_path;
          subtitle = Git_helpers.repo_description repo_path;
          content = [ null [] ];
        }

  let tree repo_path =
    let open Dream_html in
    Page.render
      HTML.
        {
          title = repo_path;
          subtitle = Git_helpers.repo_description repo_path;
          content = [ null [] ];
        }

  let commit repo_path (commit : Git_helpers.Commit.t) =
    let open Dream_html in
    let open Git_helpers in
    let message = match commit.message with Some msg -> msg | None -> "" in
    let content = HTML.[ h3 [] [ txt "%s" message ] ] in
    let title = Printf.sprintf "%s : %s" repo_path (short_hash commit.hash) in
    Page.render { title; subtitle = ""; content }
end

let error_page message =
  let open Dream_html in
  HTML.(
    html []
      [
        head []
          [
            title [] "Fatal Error";
            link [ rel "stylesheet"; href "/static/styles.css" ];
            link
              [ rel "icon"; type_ "image/x-icon"; href "/static/git_icon.svg" ];
          ];
        body []
          [
            h1 [] [ txt "Fatal Error" ];
            div
              [ id "main" ]
              [
                p [] [ b [] [ txt "%s" message ] ];
                p []
                  [
                    txt
                      "Your best course of action is to press the 'back' \
                       button in your browser.";
                  ];
              ];
          ];
      ])