type page = Dream_html.node

let tag = Dream_html.std_tag
let void = Dream_html.void_tag
let class_ value = Dream_html.string_attr "class" value
let name value = Dream_html.string_attr "name" value
let value value = Dream_html.string_attr "value" value
let rel value = Dream_html.string_attr "rel" value
let type_ value = Dream_html.string_attr "type" value
let step value = Dream_html.string_attr "step" value
let id value = Dream_html.string_attr "id" value
let tabindex value = Dream_html.string_attr "tabindex" value
let required = Dream_html.attr "required"
let href path = Dream_html.path_attr (Dream_html.uri_attr "href") path
let src path = Dream_html.path_attr (Dream_html.uri_attr "src") path
let action path = Dream_html.path_attr (Dream_html.uri_attr "action") path
let post_form = Dream_html.string_attr "method" "post"

let alert message =
  tag "p"
    [ class_ "warn"; Dream_html.string_attr "role" "alert" ]
    [ Dream_html.txt "%s" message ]

(* Render server-side link tabs. The active tab uses [aria-current] because
   each tab navigates to a complete page rather than switching a client panel. *)
let link_tabs ~aria_label ~active tabs =
  let tab_link (key, label, path) =
    let attrs =
      [
        class_ "page-tab";
        Dream_html.string_attr "href" "%s" path;
        Dream_html.attr "data-hito-app-link";
      ]
    in
    let attrs =
      if String.equal key active then
        Dream_html.string_attr "aria-current" "page" :: attrs
      else attrs
    in
    tag "a" attrs [ Dream_html.txt "%s" label ]
  in
  tag "nav"
    [ class_ "page-tabs"; Dream_html.string_attr "aria-label" "%s" aria_label ]
    (List.map tab_link tabs)

(* Render the common comparison table structure. The caller supplies grouped
   bodies, so recorded and planned workouts keep their different values. *)
let workout_evidence_table ?(upcoming = false) ?(caption_class = "sr-only")
    ~caption bodies =
  let classes =
    if upcoming then "workout-evidence-table upcoming-workout-table"
    else "workout-evidence-table"
  in
  let column label =
    tag "th"
      [ Dream_html.string_attr "scope" "col" ]
      [ Dream_html.txt "%s" label ]
  in
  let headers =
    [ column "Exercise"; column "Load (kg)" ]
    @
    if upcoming then [ column "Reps" ]
    else [ column "Δ"; column "Reps"; column "Δ" ]
  in
  tag "table"
    [ class_ "%s" classes ]
    ([
       tag "caption" [ class_ "%s" caption_class ] caption;
       tag "thead" [] [ tag "tr" [] headers ];
     ]
    @ bodies)

(* Render a prescribed workout before it has a log. Both Home and Logbook use
   this component, so the same upcoming workout shows the same evidence. *)
let upcoming_workout_card (planned : View_model.Upcoming_workout.t) =
  let format_load load = Printf.sprintf "%g" load in
  let format_reps reps = string_of_int reps in
  let rows_of_group (group : View_model.Upcoming_workout.group) =
    List.map
      (fun (exercise : View_model.Upcoming_workout.exercise) ->
        tag "tr" []
          [
            tag "th"
              [
                Dream_html.string_attr "scope" "row"; class_ "evidence-exercise";
              ]
              [ Dream_html.txt "%s" exercise.name ];
            tag "td"
              [ class_ "observation-latest" ]
              [
                Dream_html.txt "%s"
                  (Option.fold ~none:"—" ~some:format_load exercise.latest_load);
              ];
            tag "td"
              [ class_ "observation-latest" ]
              [
                Dream_html.txt "%s"
                  (Option.fold ~none:"—" ~some:format_reps exercise.latest_reps);
              ];
          ])
      group.exercises
  in
  let caption =
    [
      tag "strong"
        [ class_ "workout-evidence-caption-name" ]
        [ Dream_html.txt "%s, %s" planned.routine_name planned.name ];
      tag "span"
        [ class_ "workout-evidence-caption-status upcoming" ]
        [ Dream_html.txt "Planned on %s" planned.scheduled_on ];
    ]
  in
  tag "article"
    [ class_ "selected-upcoming-workout" ]
    [
      workout_evidence_table ~upcoming:true
        ~caption_class:"upcoming-workout-caption" ~caption
        (List.map
           (fun group -> tag "tbody" [] (rows_of_group group))
           planned.groups);
    ]