charts_ex

defmodule ChartsEx.CandlestickChart do
  @moduledoc """
  Candlestick (OHLC) chart for financial data.

  Each data point is `[open, close, low, high]`.

  ## Example

      CandlestickChart.new()
      |> CandlestickChart.title("AAPL")
      |> CandlestickChart.x_axis(["Jan", "Feb", "Mar"])
      |> CandlestickChart.add_series("Price", [
        [20.0, 34.0, 10.0, 38.0],
        [40.0, 35.0, 30.0, 50.0],
        [31.0, 38.0, 33.0, 44.0]
      ])
      |> ChartsEx.render()
  """

  @behaviour ChartsEx.Chart

  defstruct [
    :title_text,
    :title_font_size,
    :title_font_color,
    :title_font_weight,
    :title_margin,
    :title_align,
    :title_height,
    :sub_title_text,
    :sub_title_font_size,
    :sub_title_font_color,
    :sub_title_font_weight,
    :sub_title_margin,
    :sub_title_align,
    :sub_title_height,
    :width,
    :height,
    :margin,
    :font_family,
    :background_color,
    :theme,
    :legend_font_size,
    :legend_font_color,
    :legend_font_weight,
    :legend_align,
    :legend_margin,
    :legend_category,
    :legend_show,
    :x_axis_data,
    :x_axis_height,
    :x_axis_stroke_color,
    :x_axis_font_size,
    :x_axis_font_color,
    :x_axis_font_weight,
    :x_axis_name_gap,
    :x_axis_name_rotate,
    :x_axis_margin,
    :x_axis_hidden,
    :x_boundary_gap,
    :y_axis_configs,
    :y_axis_hidden,
    :grid_stroke_color,
    :grid_stroke_width,
    :series_list,
    :series_stroke_width,
    :series_label_font_color,
    :series_label_font_size,
    :series_label_font_weight,
    :series_label_formatter,
    :series_colors,
    :series_symbol,
    :series_smooth,
    :series_fill,
    # Candlestick-specific
    :candlestick_up_color,
    :candlestick_up_border_color,
    :candlestick_down_color,
    :candlestick_down_border_color
  ]

  @doc "Creates a new empty candlestick chart."
  def new, do: %__MODULE__{}

  @doc "Sets the chart title."
  def title(chart, text), do: %{chart | title_text: text}

  @doc "Sets the chart subtitle."
  def sub_title(chart, text), do: %{chart | sub_title_text: text}

  @doc "Sets the theme. See `ChartsEx.Theme.list/0` for options."
  def theme(chart, name), do: %{chart | theme: ChartsEx.Theme.validate!(name)}

  @doc "Sets the chart width in pixels."
  def width(chart, w), do: %{chart | width: w}

  @doc "Sets the chart height in pixels."
  def height(chart, h), do: %{chart | height: h}

  @doc "Sets the x-axis category labels."
  def x_axis(chart, labels), do: %{chart | x_axis_data: labels}

  @doc """
  Adds a data series to the chart.

  Each data point is `[open, close, low, high]`.

  ## Options

    * `:label_show` - whether to show value labels (boolean)

  """
  def add_series(chart, name, data, opts \\ []) do
    series = %{name: name, data: data} |> Map.merge(Map.new(opts))
    %{chart | series_list: (chart.series_list || []) ++ [series]}
  end

  @doc "Sets the chart margin as `%{left: _, top: _, right: _, bottom: _}`."
  def margin(chart, m) when is_map(m), do: %{chart | margin: m}

  @doc "Sets series colors as a list of hex strings."
  def series_colors(chart, colors), do: %{chart | series_colors: colors}

  @doc "Sets the background color as a hex string."
  def background_color(chart, color), do: %{chart | background_color: color}

  @doc "Sets the color for up (bullish) candles."
  def up_color(chart, color), do: %{chart | candlestick_up_color: color}

  @doc "Sets the border color for up candles."
  def up_border_color(chart, color), do: %{chart | candlestick_up_border_color: color}

  @doc "Sets the color for down (bearish) candles."
  def down_color(chart, color), do: %{chart | candlestick_down_color: color}

  @doc "Sets the border color for down candles."
  def down_border_color(chart, color), do: %{chart | candlestick_down_border_color: color}

  @impl ChartsEx.Chart
  def to_json(chart), do: ChartsEx.Serializer.to_json(chart, "candlestick")
end