/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
import { DataRecord } from '@superset-ui/core';
import {
  ColorFormatters,
  COMPARATOR,
  ConditionalFormattingConfig,
  MULTIPLE_VALUE_COMPARATORS,
} from '../types';

export const round = (num: number, precision = 0) =>
  Number(`${Math.round(Number(`${num}e+${precision}`))}e-${precision}`);

export const rgbToRgba = (rgb: string, alpha: number) =>
  rgb.replace(/rgb/i, 'rgba').replace(/\)/i, `,${alpha})`);

export const getOpacity = (value: number, cutoffPoint: number, extremeValue: number) => {
  const MIN_OPACITY = 0.3;
  const MAX_OPACITY = 1;

  return extremeValue === cutoffPoint
    ? MAX_OPACITY
    : round(
        Math.abs(
          ((MAX_OPACITY - MIN_OPACITY) / (extremeValue - cutoffPoint)) * (value - cutoffPoint),
        ) + MIN_OPACITY,
        2,
      );
};

export const getColorFunction = (
  {
    operator,
    targetValue,
    targetValueLeft,
    targetValueRight,
    colorScheme,
  }: ConditionalFormattingConfig,
  columnValues: number[],
) => {
  let comparatorFunction: (
    value: number,
    allValues: number[],
  ) => false | { cutoffValue: number; extremeValue: number };
  if (operator === undefined || colorScheme === undefined) {
    return () => undefined;
  }
  if (
    MULTIPLE_VALUE_COMPARATORS.includes(operator) &&
    (targetValueLeft === undefined || targetValueRight === undefined)
  ) {
    return () => undefined;
  }
  if (!MULTIPLE_VALUE_COMPARATORS.includes(operator) && targetValue === undefined) {
    return () => undefined;
  }
  switch (operator) {
    case COMPARATOR.GREATER_THAN:
      comparatorFunction = (value: number, allValues: number[]) =>
        value > targetValue!
          ? { cutoffValue: targetValue!, extremeValue: Math.max(...allValues) }
          : false;
      break;
    case COMPARATOR.LESS_THAN:
      comparatorFunction = (value: number, allValues: number[]) =>
        value < targetValue!
          ? { cutoffValue: targetValue!, extremeValue: Math.min(...allValues) }
          : false;
      break;
    case COMPARATOR.GREATER_OR_EQUAL:
      comparatorFunction = (value: number, allValues: number[]) =>
        value >= targetValue!
          ? { cutoffValue: targetValue!, extremeValue: Math.max(...allValues) }
          : false;
      break;
    case COMPARATOR.LESS_OR_EQUAL:
      comparatorFunction = (value: number, allValues: number[]) =>
        value <= targetValue!
          ? { cutoffValue: targetValue!, extremeValue: Math.min(...allValues) }
          : false;
      break;
    case COMPARATOR.EQUAL:
      comparatorFunction = (value: number) =>
        value === targetValue! ? { cutoffValue: targetValue!, extremeValue: targetValue! } : false;
      break;
    case COMPARATOR.NOT_EQUAL:
      comparatorFunction = (value: number, allValues: number[]) => {
        if (value === targetValue!) {
          return false;
        }
        const max = Math.max(...allValues);
        const min = Math.min(...allValues);
        return {
          cutoffValue: targetValue!,
          extremeValue: Math.abs(targetValue! - min) > Math.abs(max - targetValue!) ? min : max,
        };
      };
      break;
    case COMPARATOR.BETWEEN:
      comparatorFunction = (value: number) =>
        value > targetValueLeft! && value < targetValueRight!
          ? { cutoffValue: targetValueLeft!, extremeValue: targetValueRight! }
          : false;
      break;
    case COMPARATOR.BETWEEN_OR_EQUAL:
      comparatorFunction = (value: number) =>
        value >= targetValueLeft! && value <= targetValueRight!
          ? { cutoffValue: targetValueLeft!, extremeValue: targetValueRight! }
          : false;
      break;
    case COMPARATOR.BETWEEN_OR_LEFT_EQUAL:
      comparatorFunction = (value: number) =>
        value >= targetValueLeft! && value < targetValueRight!
          ? { cutoffValue: targetValueLeft!, extremeValue: targetValueRight! }
          : false;
      break;
    case COMPARATOR.BETWEEN_OR_RIGHT_EQUAL:
      comparatorFunction = (value: number) =>
        value > targetValueLeft! && value <= targetValueRight!
          ? { cutoffValue: targetValueLeft!, extremeValue: targetValueRight! }
          : false;
      break;
    default:
      comparatorFunction = () => false;
      break;
  }

  return (value: number) => {
    const compareResult = comparatorFunction(value, columnValues);
    if (compareResult === false) return undefined;
    const { cutoffValue, extremeValue } = compareResult;
    return rgbToRgba(colorScheme, getOpacity(value, cutoffValue, extremeValue));
  };
};

export const getColorFormatters = (
  columnConfig: ConditionalFormattingConfig[] | undefined,
  data: DataRecord[],
) =>
  columnConfig?.reduce((acc: ColorFormatters, config: ConditionalFormattingConfig) => {
    if (
      config?.column !== undefined &&
      config?.operator !== undefined &&
      (MULTIPLE_VALUE_COMPARATORS.includes(config?.operator)
        ? config?.targetValueLeft !== undefined && config?.targetValueRight !== undefined
        : config?.targetValue !== undefined)
    ) {
      acc.push({
        column: config?.column,
        getColorFromValue: getColorFunction(
          config,
          data.map(row => row[config.column!] as number),
        ),
      });
    }
    return acc;
  }, []) ?? [];