import { type ChartInstance } from '@/domain/entities/ChartInstance';
import { type StyleConfig } from '@/domain/entities/StyleConfig';
import { type FieldBinding } from '@/domain/entities/FieldBinding';

function getBinding(bindings: FieldBinding[], axis: string): FieldBinding | undefined {
  return bindings.find((b) => b.axis === axis);
}

function applyCommonStyle(option: Record<string, any>, style: StyleConfig): void {
  if (style.title.visible) {
    option.title = {
      text: style.title.text,
      left: style.title.align,
      textStyle: {
        fontSize: style.title.fontSize,
        fontWeight: style.title.fontWeight,
        color: style.title.color,
      },
    };
  }

  if (style.legend.visible) {
    option.legend = {
      show: true,
      orient: style.legend.orient,
      top: style.legend.position === 'top' ? 'top' : style.legend.position === 'bottom' ? 'bottom' : 'middle',
      left: style.legend.position === 'left' ? 'left' : style.legend.position === 'right' ? 'right' : 'center',
      textStyle: {
        fontSize: style.legend.fontSize,
        color: style.legend.color,
      },
    };
  } else {
    option.legend = { show: false };
  }

  option.backgroundColor = style.background.color !== '' ? style.background.color : 'transparent';

  if (style.animation.enabled) {
    option.animation = true;
    option.animationDuration = style.animation.duration;
    option.animationEasing = style.animation.easing === 'ease-in'
      ? 'cubicIn'
      : style.animation.easing === 'ease-out'
        ? 'cubicOut'
        : style.animation.easing === 'ease-in-out'
          ? 'cubicInOut'
          : 'linear';
  } else {
    option.animation = false;
  }

  option.grid = {
    containLabel: true,
    top: 60,
    right: 30,
    bottom: 30,
    left: 30,
  };
}

function buildAxisConfig(style: StyleConfig, isHorizontal: boolean) {
  const xAxisStyle = isHorizontal ? style.yAxis : style.xAxis;
  const yAxisStyle = isHorizontal ? style.xAxis : style.yAxis;

  const xAxis: Record<string, any> = {
    show: xAxisStyle.visible,
    axisLabel: {
      show: xAxisStyle.labelVisible,
      fontSize: xAxisStyle.labelFontSize,
      color: xAxisStyle.labelColor,
      rotate: xAxisStyle.labelRotation,
    },
    splitLine: {
      show: xAxisStyle.gridVisible,
      lineStyle: { color: xAxisStyle.gridColor },
    },
  };

  if (xAxisStyle.titleVisible && xAxisStyle.titleText) {
    xAxis.name = xAxisStyle.titleText;
  }

  const yAxis: Record<string, any> = {
    show: yAxisStyle.visible,
    axisLabel: {
      show: yAxisStyle.labelVisible,
      fontSize: yAxisStyle.labelFontSize,
      color: yAxisStyle.labelColor,
      rotate: yAxisStyle.labelRotation,
    },
    splitLine: {
      show: yAxisStyle.gridVisible,
      lineStyle: { color: yAxisStyle.gridColor },
    },
  };

  if (yAxisStyle.titleVisible && yAxisStyle.titleText) {
    yAxis.name = yAxisStyle.titleText;
  }

  return { xAxis, yAxis };
}

function buildLabelConfig(style: StyleConfig) {
  if (!style.dataLabel.visible) return { show: false };
  let formatter: string | undefined;
  switch (style.dataLabel.format) {
    case 'percent':
      formatter = '{b}: {d}%';
      break;
    case 'custom':
      formatter = style.dataLabel.template;
      break;
    case 'value':
    default:
      formatter = '{c}';
      break;
  }
  return {
    show: true,
    fontSize: style.dataLabel.fontSize,
    color: style.dataLabel.color,
    position: style.dataLabel.position,
    formatter,
  };
}

export function buildBarOption(
  chart: ChartInstance,
  data: Record<string, any>[],
): Record<string, any> {
  const { bindings, style, type } = chart;
  const xBinding = getBinding(bindings, 'x');
  const yBinding = getBinding(bindings, 'y');
  const seriesBinding = getBinding(bindings, 'series');
  const isHorizontal = type === 'horizontal-bar';
  const isStacked = type === 'stacked-bar';
  const isGrouped = type === 'grouped-bar';

  const xField = xBinding?.columnName ?? '';
  const yField = yBinding?.columnName ?? '';

  const option: Record<string, any> = {};
  applyCommonStyle(option, style);

  const categories = [...new Set(data.map((row) => String(row[xField])))];
  const { xAxis, yAxis } = buildAxisConfig(style, isHorizontal);

  const label = buildLabelConfig(style);

  const colorBinding = getBinding(bindings, 'color');
  const splitField = seriesBinding?.columnName ?? colorBinding?.columnName;
  const hasSplit = !!splitField;

  if (hasSplit) {
    // Multi-series: split by series or color field
    const splitNames = [...new Set(data.map((row) => String(row[splitField])))];

    const seriesList = splitNames.map((name, idx) => {
      const seriesData = categories.map((cat) => {
        // Sum all matching rows (there may be multiple)
        const matchingRows = data.filter(
          (r) => String(r[xField]) === cat && String(r[splitField]) === name,
        );
        return matchingRows.reduce((sum, r) => sum + (Number(r[yField]) || 0), 0);
      });

      return {
        name,
        type: 'bar',
        stack: isStacked ? 'total' : undefined,
        data: seriesData,
        itemStyle: {
          color: style.colors[idx % style.colors.length],
        },
        label,
      };
    });

    if (isHorizontal) {
      option.yAxis = { ...xAxis, type: 'category', data: categories };
      option.xAxis = { ...yAxis, type: 'value' };
    } else {
      option.xAxis = { ...xAxis, type: 'category', data: categories };
      option.yAxis = { ...yAxis, type: 'value' };
    }
    option.series = seriesList;
    option.tooltip = { trigger: 'axis' };
  } else {
    // Single series: aggregate by x category
    const seriesData = categories.map((cat) => {
      const matchingRows = data.filter((r) => String(r[xField]) === cat);
      return matchingRows.reduce((sum, r) => sum + (Number(r[yField]) || 0), 0);
    });

    if (isHorizontal) {
      option.yAxis = { ...xAxis, type: 'category', data: categories };
      option.xAxis = { ...yAxis, type: 'value' };
    } else {
      option.xAxis = { ...xAxis, type: 'category', data: categories };
      option.yAxis = { ...yAxis, type: 'value' };
    }

    option.series = [
      {
        type: 'bar',
        data: seriesData,
        itemStyle: {
          color: style.colors[0],
        },
        label,
      },
    ];
    option.tooltip = { trigger: 'axis' };
  }

  return option;
}