import { expect, test } from "vitest"

import {
  compositeLinearRgbColorValueOverBackground,
  compositeSrgbColorValueOverBackground,
  darkenSrgbColorValue,
  fadeSrgbColorValue,
  lightenSrgbColorValue,
  mixLinearRgbColorValues,
  mixSrgbColorValues,
  shadeSrgbColorValue,
  tintSrgbColorValue,
  toneSrgbColorValue,
} from "#Source/color/index.ts"

test("mixLinearRgbColorValues mixes directly on the linear layer", () => {
  expect(
    mixLinearRgbColorValues(
      { red: 1, green: 0, blue: 0, alpha: 1 },
      { red: 0, green: 0, blue: 1, alpha: 1 },
      0.5,
    ),
  ).toEqual({ red: 0.5, green: 0, blue: 0.5, alpha: 1 })

  expect(() =>
    mixLinearRgbColorValues(
      { red: 1, green: 0, blue: 0, alpha: 1 },
      { red: 0, green: 0, blue: 1, alpha: 1 },
      -0.1,
    ),
  ).toThrow(RangeError)
})

test("mixSrgbColorValues mixes through the explicit sRGB to linear pipeline", () => {
  expect(
    mixSrgbColorValues(
      { red: 255, green: 0, blue: 0, alpha: 1 },
      { red: 0, green: 0, blue: 255, alpha: 1 },
      0.5,
    ),
  ).toEqual({ red: 188, green: 0, blue: 188, alpha: 1 })

  expect(
    mixSrgbColorValues(
      { red: 255, green: 0, blue: 0, alpha: 1 },
      { red: 255, green: 255, blue: 255, alpha: 1 },
      0.5,
    ),
  ).toEqual({ red: 255, green: 188, blue: 188, alpha: 1 })
})

test("compositeLinearRgbColorValueOverBackground composites directly on the linear layer", () => {
  expect(
    compositeLinearRgbColorValueOverBackground(
      { red: 1, green: 1, blue: 1, alpha: 0.5 },
      { red: 0, green: 0, blue: 1, alpha: 1 },
    ),
  ).toEqual({ red: 0.5, green: 0.5, blue: 1, alpha: 1 })

  expect(
    compositeLinearRgbColorValueOverBackground(
      { red: 1, green: 0, blue: 0, alpha: 1 },
      { red: 0, green: 0, blue: 1, alpha: 1 },
    ),
  ).toEqual({ red: 1, green: 0, blue: 0, alpha: 1 })
})

test("compositeSrgbColorValueOverBackground composites through the explicit sRGB to linear pipeline", () => {
  expect(
    compositeSrgbColorValueOverBackground(
      { red: 255, green: 255, blue: 255, alpha: 0.5 },
      { red: 0, green: 0, blue: 255, alpha: 1 },
    ),
  ).toEqual({ red: 188, green: 188, blue: 255, alpha: 1 })

  expect(
    compositeSrgbColorValueOverBackground(
      { red: 255, green: 0, blue: 0, alpha: 1 },
      { red: 0, green: 0, blue: 255, alpha: 1 },
    ),
  ).toEqual({ red: 255, green: 0, blue: 0, alpha: 1 })
})

test("fadeSrgbColorValue updates alpha while keeping channels stable", () => {
  expect(fadeSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0.4)).toEqual({
    red: 51,
    green: 102,
    blue: 153,
    alpha: 0.4,
  })

  expect(() => fadeSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, -0.1)).toThrow(
    RangeError,
  )
})

test("tintSrgbColorValue stays on the legal RGB branch pipeline", () => {
  expect(tintSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0.5)).toEqual({
    red: 190,
    green: 198,
    blue: 212,
    alpha: 1,
  })
  expect(tintSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0)).toEqual({
    red: 51,
    green: 102,
    blue: 153,
    alpha: 1,
  })
  expect(() => tintSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 1.1)).toThrow(
    RangeError,
  )
})

test("shadeSrgbColorValue stays on the legal RGB branch pipeline", () => {
  expect(shadeSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0.5)).toEqual({
    red: 35,
    green: 73,
    blue: 111,
    alpha: 1,
  })
  expect(shadeSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0)).toEqual({
    red: 51,
    green: 102,
    blue: 153,
    alpha: 1,
  })
})

test("toneSrgbColorValue stays on the legal RGB branch pipeline", () => {
  expect(toneSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0.5)).toEqual({
    red: 141,
    green: 153,
    blue: 171,
    alpha: 1,
  })
  expect(toneSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0)).toEqual({
    red: 51,
    green: 102,
    blue: 153,
    alpha: 1,
  })
})

test("lightenSrgbColorValue stays on the legal RGB branch pipeline", () => {
  expect(lightenSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0.25)).toEqual({
    red: 143,
    green: 160,
    blue: 186,
    alpha: 1,
  })
  expect(lightenSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0)).toEqual({
    red: 51,
    green: 102,
    blue: 153,
    alpha: 1,
  })
})

test("darkenSrgbColorValue stays on the legal RGB branch pipeline", () => {
  expect(darkenSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0.25)).toEqual({
    red: 44,
    green: 89,
    blue: 134,
    alpha: 1,
  })
  expect(darkenSrgbColorValue({ red: 51, green: 102, blue: 153, alpha: 1 }, 0)).toEqual({
    red: 51,
    green: 102,
    blue: 153,
    alpha: 1,
  })
})