phia_ui

defmodule PhiaUi.Components.WeekPicker do
  @moduledoc """
  Week selection input — styled native `<input type="week">`.

  Wraps the browser's native week picker with PhiaUI's input styling (borders,
  focus ring, size variants, error state). Supports standalone use or
  Phoenix form field integration with changeset error display.

  The value format follows the ISO 8601 week notation: `"YYYY-Www"` (e.g. `"2026-W10"`).

  Present in scheduling and reporting UIs: Mantine `WeekPicker`, Ant Design
  `DatePicker` (picker="week"), MUI `DatePicker` with week view.

  Zero JavaScript — uses the native browser week control.

  ## Examples

      <%!-- Standalone --%>
      <.week_picker id="report_week" name="report_week" label="Reporting Week" value="2026-W10" />

      <%!-- With min/max constraint --%>
      <.week_picker id="sprint" name="sprint" min="2026-W01" max="2026-W52" />

      <%!-- Form field integration --%>
      <.week_picker
        id="event_week"
        name={@form[:week].name}
        value={@form[:week].value}
        errors={Enum.map(@form[:week].errors, &translate_error/1)}
        label="Event Week"
      />
  """

  use Phoenix.Component

  import PhiaUi.ClassMerger, only: [cn: 1]

  # ---------------------------------------------------------------------------
  # Attributes
  # ---------------------------------------------------------------------------

  attr(:id, :string, default: nil, doc: "HTML `id` for the input and label `for` link.")
  attr(:name, :string, default: nil, doc: "HTML `name` for form submission.")

  attr(:value, :string,
    default: nil,
    doc: "Current week value in ISO format, e.g. `\"2026-W10\"`."
  )

  attr(:label, :string, default: nil, doc: "Label text rendered above the input.")
  attr(:description, :string, default: nil, doc: "Helper text rendered below the label.")
  attr(:errors, :list, default: [], doc: "List of error message strings.")

  attr(:disabled, :boolean, default: false, doc: "Disables the input.")

  attr(:size, :atom,
    default: :default,
    values: [:sm, :default, :lg],
    doc: "Input height/padding: `:sm` (h-8), `:default` (h-10), `:lg` (h-12)."
  )

  attr(:class, :string, default: nil, doc: "Additional CSS classes merged onto the input.")

  attr(:rest, :global,
    include: ~w(required placeholder phx-debounce min max),
    doc: "HTML attributes forwarded to the `<input>` element."
  )

  # ---------------------------------------------------------------------------
  # Component
  # ---------------------------------------------------------------------------

  def week_picker(assigns) do
    ~H"""
    <div class="space-y-2">
      <label
        :if={@label}
        for={@id}
        class="text-sm font-medium leading-none peer-disabled:cursor-not-allowed peer-disabled:opacity-70"
      >
        {@label}
      </label>

      <p :if={@description} class="text-sm text-muted-foreground">
        {@description}
      </p>

      <input
        type="week"
        id={@id}
        name={@name}
        value={@value}
        disabled={@disabled}
        class={cn([input_class(@size), error_class(@errors), @class])}
        {@rest}
      />

      <p :for={error <- @errors} class="text-sm font-medium text-destructive">
        {error}
      </p>
    </div>
    """
  end

  # ---------------------------------------------------------------------------
  # Private helpers
  # ---------------------------------------------------------------------------

  defp input_class(:sm) do
    "flex h-8 w-full rounded-md border border-input bg-background px-2 py-1 text-xs " <>
      "ring-offset-background focus-visible:outline-none focus-visible:ring-2 " <>
      "focus-visible:ring-ring focus-visible:ring-offset-2 " <>
      "disabled:cursor-not-allowed disabled:opacity-50"
  end

  defp input_class(:default) do
    "flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm " <>
      "ring-offset-background focus-visible:outline-none focus-visible:ring-2 " <>
      "focus-visible:ring-ring focus-visible:ring-offset-2 " <>
      "disabled:cursor-not-allowed disabled:opacity-50"
  end

  defp input_class(:lg) do
    "flex h-12 w-full rounded-md border border-input bg-background px-4 py-3 text-base " <>
      "ring-offset-background focus-visible:outline-none focus-visible:ring-2 " <>
      "focus-visible:ring-ring focus-visible:ring-offset-2 " <>
      "disabled:cursor-not-allowed disabled:opacity-50"
  end

  defp error_class([]), do: nil
  defp error_class(_), do: "border-destructive focus-visible:ring-destructive"
end