defmodule GitSyncWeb.CoreComponents do
  @moduledoc """
  Provides core UI components.

  At first glance, this module may seem daunting, but its goal is to provide
  core building blocks for your application, such as tables, forms, and
  inputs. The components consist mostly of markup and are well-documented
  with doc strings and declarative assigns. You may customize and style
  them in any way you want, based on your application growth and needs.

  Styling is hand-written CSS in `assets/css/app.css`; components carry
  semantic class names rather than utility classes.

    * [Phoenix.Component](https://phoenix-live-view.hexdocs.pm/Phoenix.Component.html) -
      the component system used by Phoenix. Some components, such as `<.link>`
      and `<.form>`, are defined there.

  """
  use Phoenix.Component

  @doc """
  Renders flash notices.

  ## Examples

      <.flash kind={:info} flash={@flash} />
      <.flash id="welcome-back" kind={:info}>Welcome Back!</.flash>
  """
  attr :id, :string, doc: "the optional id of flash container"
  attr :flash, :map, default: %{}, doc: "the map of flash messages to display"
  attr :title, :string, default: nil
  attr :kind, :atom, values: [:info, :error], doc: "used for styling and flash lookup"
  attr :rest, :global, doc: "the arbitrary HTML attributes to add to the flash container"

  slot :inner_block, doc: "the optional inner block that renders the flash message"

  def flash(assigns) do
    assigns = assign_new(assigns, :id, fn -> "flash-#{assigns.kind}" end)

    ~H"""
    <div
      :if={msg = render_slot(@inner_block) || Phoenix.Flash.get(@flash, @kind)}
      id={@id}
      data-flash
      data-kind={@kind}
      data-flash-autodismiss={@kind == :info}
      role="alert"
      {@rest}
    >
      <div>
        <p :if={@title}><strong>{@title}</strong></p>
        <p>{msg}</p>
      </div>
      <button type="button" data-flash-close aria-label="close">&times;</button>
    </div>
    """
  end

  @doc """
  Renders a button with navigation support.

  ## Examples

      <.button>Send!</.button>
      <.button variant="secondary">Send!</.button>
      <.button navigate={~p"/"}>Home</.button>
  """
  attr :rest, :global, include: ~w(href navigate patch method download name value disabled type)
  attr :class, :any
  attr :variant, :string, values: ~w(primary secondary), default: "primary"
  slot :inner_block, required: true

  def button(%{rest: rest} = assigns) do
    assigns = assign_new(assigns, :class, fn -> assigns.variant end)

    if rest[:href] || rest[:navigate] || rest[:patch] do
      ~H"""
      <.link class={["button", @class]} {@rest}>
        {render_slot(@inner_block)}
      </.link>
      """
    else
      ~H"""
      <button class={@class} {@rest}>
        {render_slot(@inner_block)}
      </button>
      """
    end
  end

  @doc """
  Renders an input with label and error messages.

  A `Phoenix.HTML.FormField` may be passed as argument,
  which is used to retrieve the input name, id, and values.
  Otherwise all attributes may be passed explicitly.

  ## Types

  This function accepts all HTML input types, considering that:

    * You may also set `type="select"` to render a `<select>` tag

    * `type="checkbox"` is used exclusively to render boolean values

    * For live file uploads, see `Phoenix.Component.live_file_input/1`

  See https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input
  for more information. Unsupported types, such as radio, are best
  written directly in your templates.

  ## Examples

  ```heex
  <.input field={@form[:email]} type="email" />
  <.input name="my-input" errors={["oh no!"]} />
  ```

  ## Select type

  When using `type="select"`, you must pass the `options` and optionally
  a `value` to mark which option should be preselected.

  ```heex
  <.input field={@form[:user_type]} type="select" options={["Admin": "admin", "User": "user"]} />
  ```

  For more information on what kind of data can be passed to `options` see
  [`options_for_select`](https://phoenix-html.hexdocs.pm/Phoenix.HTML.Form.html#options_for_select/2).
  """
  attr :id, :any, default: nil
  attr :name, :any
  attr :label, :string, default: nil
  attr :value, :any

  attr :type, :string,
    default: "text",
    values: ~w(checkbox color date datalist datetime-local email file month number password
               search select tel text textarea time url week hidden)

  attr :field, Phoenix.HTML.FormField,
    doc: "a form field struct retrieved from the form, for example: @form[:email]"

  attr :errors, :list, default: []
  attr :checked, :boolean, doc: "the checked flag for checkbox inputs"
  attr :prompt, :string, default: nil, doc: "the prompt for select inputs"
  attr :options, :list, doc: "the options to pass to Phoenix.HTML.Form.options_for_select/2"
  attr :multiple, :boolean, default: false, doc: "the multiple flag for select inputs"
  attr :class, :any, default: nil, doc: "the input class to use over defaults"
  attr :error_class, :any, default: nil, doc: "the input error class to use over defaults"

  attr :rest, :global,
    include: ~w(accept autocomplete capture cols disabled form list max maxlength min minlength
                multiple pattern placeholder readonly required rows size step)

  def input(%{field: %Phoenix.HTML.FormField{} = field} = assigns) do
    errors = if Phoenix.Component.used_input?(field), do: field.errors, else: []

    assigns
    |> assign(field: nil, id: assigns.id || field.id)
    |> assign(:errors, Enum.map(errors, &translate_error(&1)))
    |> assign_new(:name, fn -> if assigns.multiple, do: field.name <> "[]", else: field.name end)
    |> assign_new(:value, fn -> field.value end)
    |> input()
  end

  def input(%{type: "hidden"} = assigns) do
    ~H"""
    <input type="hidden" id={@id} name={@name} value={@value} {@rest} />
    """
  end

  def input(%{type: "checkbox"} = assigns) do
    assigns =
      assign_new(assigns, :checked, fn ->
        Phoenix.HTML.Form.normalize_value("checkbox", assigns[:value])
      end)

    ~H"""
    <div class="field checkbox">
      <label for={@id}>
        <input
          type="hidden"
          name={@name}
          value="false"
          disabled={@rest[:disabled]}
          form={@rest[:form]}
        />
        <input
          type="checkbox"
          id={@id}
          name={@name}
          value="true"
          checked={@checked}
          class={@class}
          {@rest}
        />{@label}
      </label>
      <.error :for={msg <- @errors}>{msg}</.error>
    </div>
    """
  end

  def input(%{type: "select"} = assigns) do
    ~H"""
    <div class="field">
      <label for={@id}>
        <span :if={@label}>{@label}</span>
        <select
          id={@id}
          name={@name}
          class={[@class, @errors != [] && @error_class]}
          aria-invalid={@errors != []}
          multiple={@multiple}
          {@rest}
        >
          <option :if={@prompt} value="">{@prompt}</option>
          {Phoenix.HTML.Form.options_for_select(@options, @value)}
        </select>
      </label>
      <.error :for={msg <- @errors}>{msg}</.error>
    </div>
    """
  end

  def input(%{type: "datalist"} = assigns) do
    assigns = assign(assigns, :list_id, "#{assigns.id}-options")

    ~H"""
    <div class="field">
      <label for={@id}>
        <span :if={@label}>{@label}</span>
        <input
          type="text"
          name={@name}
          id={@id}
          value={Phoenix.HTML.Form.normalize_value("text", @value)}
          list={@list_id}
          class={[@class, @errors != [] && @error_class]}
          aria-invalid={@errors != []}
          {@rest}
        />
      </label>
      <datalist id={@list_id}>
        <option :for={option <- @options} value={option}></option>
      </datalist>
      <.error :for={msg <- @errors}>{msg}</.error>
    </div>
    """
  end

  def input(%{type: "textarea"} = assigns) do
    ~H"""
    <div class="field">
      <label for={@id}>
        <span :if={@label}>{@label}</span>
        <textarea
          id={@id}
          name={@name}
          class={[@class, @errors != [] && @error_class]}
          aria-invalid={@errors != []}
          {@rest}
        >{Phoenix.HTML.Form.normalize_value("textarea", @value)}</textarea>
      </label>
      <.error :for={msg <- @errors}>{msg}</.error>
    </div>
    """
  end

  # All other inputs text, datetime-local, url, password, etc. are handled here...
  def input(assigns) do
    ~H"""
    <div class="field">
      <label for={@id}>
        <span :if={@label}>{@label}</span>
        <input
          type={@type}
          name={@name}
          id={@id}
          value={Phoenix.HTML.Form.normalize_value(@type, @value)}
          class={[@class, @errors != [] && @error_class]}
          aria-invalid={@errors != []}
          {@rest}
        />
      </label>
      <.error :for={msg <- @errors}>{msg}</.error>
    </div>
    """
  end

  # Helper used by inputs to generate form errors
  defp error(assigns) do
    ~H"""
    <p class="field-error">{render_slot(@inner_block)}</p>
    """
  end

  @doc """
  Renders a header with title.
  """
  slot :inner_block, required: true
  slot :subtitle
  slot :actions

  def header(assigns) do
    ~H"""
    <header>
      <div>
        <h1>{render_slot(@inner_block)}</h1>
        <p :if={@subtitle != []}>{render_slot(@subtitle)}</p>
      </div>
      <div :if={@actions != []}>{render_slot(@actions)}</div>
    </header>
    """
  end

  @doc """
  Renders a table with generic styling.

  ## Examples

      <.table id="users" rows={@users}>
        <:col :let={user} label="id">{user.id}</:col>
        <:col :let={user} label="username">{user.username}</:col>
      </.table>
  """
  attr :id, :string, required: true
  attr :rows, :list, required: true
  attr :row_id, :any, default: nil, doc: "the function for generating the row id"

  attr :row_item, :any,
    default: &Function.identity/1,
    doc: "the function for mapping each row before calling the :col and :action slots"

  slot :col, required: true do
    attr :label, :string
  end

  slot :action, doc: "the slot for showing user actions in the last table column"

  def table(assigns) do
    ~H"""
    <table>
      <thead>
        <tr>
          <th :for={col <- @col}>{col[:label]}</th>
          <th :if={@action != []}>
            <span class="sr-only">Actions</span>
          </th>
        </tr>
      </thead>
      <tbody id={@id}>
        <tr :for={row <- @rows} id={@row_id && @row_id.(row)}>
          <td :for={col <- @col}>
            {render_slot(col, @row_item.(row))}
          </td>
          <td :if={@action != []}>
            <div>
              <%= for action <- @action do %>
                {render_slot(action, @row_item.(row))}
              <% end %>
            </div>
          </td>
        </tr>
      </tbody>
    </table>
    """
  end

  @doc """
  Renders a data list.

  ## Examples

      <.list>
        <:item title="Title">{@post.title}</:item>
        <:item title="Views">{@post.views}</:item>
      </.list>
  """
  slot :item, required: true do
    attr :title, :string, required: true
  end

  def list(assigns) do
    ~H"""
    <dl class="data-list">
      <%= for item <- @item do %>
        <dt>{item.title}</dt>
        <dd>{render_slot(item)}</dd>
      <% end %>
    </dl>
    """
  end

  @doc """
  Translates an error message using gettext.
  """
  def translate_error({msg, opts}) do
    # You can make use of gettext to translate error messages by
    # uncommenting and adjusting the following code:

    # if count = opts[:count] do
    #   Gettext.dngettext(GitSyncWeb.Gettext, "errors", msg, msg, count, opts)
    # else
    #   Gettext.dgettext(GitSyncWeb.Gettext, "errors", msg, opts)
    # end

    Enum.reduce(opts, msg, fn {key, value}, acc ->
      String.replace(acc, "%{#{key}}", fn _ -> to_string(value) end)
    end)
  end

  @doc """
  Translates the errors for a field from a keyword list of errors.
  """
  def translate_errors(errors, field) when is_list(errors) do
    for {^field, {msg, opts}} <- errors, do: translate_error({msg, opts})
  end
end