import { Platform } from 'react-native';
import { ScreenProps } from '../../types';

// This value must be kept in sync with native side.
export const SHEET_FIT_TO_CONTENTS = [-1];
export const SHEET_COMPAT_LARGE = [1.0];
export const SHEET_COMPAT_MEDIUM = [0.5];
export const SHEET_COMPAT_ALL = [0.5, 1.0];
export const SHEET_DIMMED_ALWAYS = -1;

export function assertDetentsArrayIsSorted(array: number[]) {
  for (let i = 1; i < array.length; i++) {
    if (array[i - 1] > array[i]) {
      throw new Error(
        '[RNScreens] The detent array is not sorted in ascending order!',
      );
    }
  }
}

// These exist to transform old 'legacy' values used by the formsheet API to the new API shape.
// We can get rid of it, once we get rid of support for legacy values: 'large', 'medium', 'all'.
export function resolveSheetAllowedDetents(
  allowedDetentsCompat: ScreenProps['sheetAllowedDetents'],
): number[] {
  if (Array.isArray(allowedDetentsCompat)) {
    if (Platform.OS === 'android' && allowedDetentsCompat.length > 3) {
      if (__DEV__) {
        console.warn(
          '[RNScreens] Sheets API on Android do accept only up to 3 values. Any surplus value are ignored.',
        );
      }
      allowedDetentsCompat = allowedDetentsCompat.slice(0, 3);
    }
    if (__DEV__) {
      assertDetentsArrayIsSorted(allowedDetentsCompat);
    }
    return allowedDetentsCompat;
  } else if (allowedDetentsCompat === 'fitToContents') {
    return SHEET_FIT_TO_CONTENTS;
  } else if (allowedDetentsCompat === 'large') {
    return SHEET_COMPAT_LARGE;
  } else if (allowedDetentsCompat === 'medium') {
    return SHEET_COMPAT_MEDIUM;
  } else if (allowedDetentsCompat === 'all') {
    return SHEET_COMPAT_ALL;
  } else {
    // Safe default, only large detent is allowed.
    return SHEET_COMPAT_LARGE;
  }
}

export function resolveSheetLargestUndimmedDetent(
  lud: ScreenProps['sheetLargestUndimmedDetentIndex'],
  lastDetentIndex: number,
): number {
  if (typeof lud === 'number') {
    if (!isIndexInClosedRange(lud, SHEET_DIMMED_ALWAYS, lastDetentIndex)) {
      if (__DEV__) {
        throw new Error(
          "[RNScreens] Provided value of 'sheetLargestUndimmedDetentIndex' prop is out of bounds of 'sheetAllowedDetents' array.",
        );
      }
      // Return default in production
      return SHEET_DIMMED_ALWAYS;
    }
    return lud;
  } else if (lud === 'last') {
    return lastDetentIndex;
  } else if (lud === 'none' || lud === 'all') {
    return SHEET_DIMMED_ALWAYS;
  } else if (lud === 'large') {
    return 1;
  } else if (lud === 'medium') {
    return 0;
  } else {
    // Safe default, every detent is dimmed
    return SHEET_DIMMED_ALWAYS;
  }
}

export function resolveSheetInitialDetentIndex(
  index: ScreenProps['sheetInitialDetentIndex'],
  lastDetentIndex: number,
): number {
  if (index === 'last') {
    index = lastDetentIndex;
  } else if (index == null) {
    // Intentional check for undefined & null ^
    index = 0;
  }
  if (!isIndexInClosedRange(index, 0, lastDetentIndex)) {
    if (__DEV__) {
      throw new Error(
        "[RNScreens] Provided value of 'sheetInitialDetentIndex' prop is out of bounds of 'sheetAllowedDetents' array.",
      );
    }
    // Return default in production
    return 0;
  }
  return index;
}

function isIndexInClosedRange(
  value: number,
  lowerBound: number,
  upperBound: number,
): boolean {
  return Number.isInteger(value) && value >= lowerBound && value <= upperBound;
}