package memoize

import (
	"testing"
)

var intData = []struct {
	in    int
	calls int
}{
	{0, 1},
	{1, 2},
	{0, 2},
	{2, 3},
	{2, 3},
}

func TestInt1(t *testing.T) {
	numCalls := 0
	var f1 func(int) int
	f2 := func(i int) int {
		numCalls++
		return i
	}
	Memoize(&f1, f2)
	for _, d := range intData {
		out := f1(d.in)
		if out != d.in {
			t.Errorf("Got %d, want %d", out, d.in)
		}
		if numCalls != d.calls {
			t.Errorf("Num calls = %d, want %d", numCalls, d.calls)
		}
	}
}

func TestReassign(t *testing.T) {
	numCalls := 0
	f := func(i int) int {
		numCalls++
		return i
	}
	Memoize(&f, f)
	for _, d := range intData {
		out := f(d.in)
		if out != d.in {
			t.Errorf("Got %d, want %d", out, d.in)
		}
		if numCalls != d.calls {
			t.Errorf("Num calls = %d, want %d", numCalls, d.calls)
		}
	}
}

var int2Data = []struct {
	in1, in2 int
	calls    int
}{
	{0, 0, 1},
	{0, 1, 2},
	{1, 0, 3},
	{0, 0, 3},
	{0, 1, 3},
	{1, 0, 3},
}

func TestInt2(t *testing.T) {
	numCalls := 0
	f := func(a, b int) int {
		numCalls++
		return a + b
	}
	Memoize(&f, f)
	for _, d := range int2Data {
		out := f(d.in1, d.in2)
		if out != d.in1+d.in2 {
			t.Errorf("Got %d, want %d + %d", out, d.in1, d.in2)
		}
		if numCalls != d.calls {
			t.Errorf("Num calls = %d, want %d", numCalls, d.calls)
		}
	}
}

var int22Data = []struct {
	in1, in2 int
	calls    int
}{
	{0, 0, 1},
	{1, 0, 2},
	{0, 1, 3},
	{0, 1, 3},
	{1, 0, 3},
	{0, 0, 3},
}

func TestInt22(t *testing.T) {
	numCalls := 0
	f := func(a, b int) (int, int) {
		numCalls++
		return b, a
	}
	Memoize(&f, f)
	for _, d := range int22Data {
		out1, out2 := f(d.in1, d.in2)
		if out1 != d.in2 || out2 != d.in1 {
			t.Errorf("Got (%d, %d) from (%d, %d)", out1, out2,
				d.in1, d.in2)
		}
		if numCalls != d.calls {
			t.Errorf("Num calls = %d, want %d", numCalls, d.calls)
		}
	}
}

var mixedData = []struct {
	in1   int
	in2   string
	calls int
}{
	{0, "zero", 1},
	{1, "zero", 2},
	{0, "one", 3},
	{1, "one", 4},
	{0, "zero", 4},
	{1, "zero", 4},
	{0, "one", 4},
	{1, "one", 4},
}

func TestMixed(t *testing.T) {
	numCalls := 0
	f := func(a int, b string) (string, int) {
		numCalls++
		return b, a
	}
	Memoize(&f, f)
	for _, d := range mixedData {
		out1, out2 := f(d.in1, d.in2)
		if out1 != d.in2 || out2 != d.in1 {
			t.Errorf("Got (%s, %d) from (%d, %s)", out1, out2,
				d.in1, d.in2)
		}
		if numCalls != d.calls {
			t.Errorf("Num calls = %d, want %d", numCalls, d.calls)
		}
	}
}