package crypto

import (
	"testing"

	"git.smesh.lol/gnarl-hamadryad/ratio"
)

func TestDefaultParamsValid(t *testing.T) {
	for _, level := range []SecurityLevel{Security128, Security192, Security256} {
		p := DefaultParams(level)
		if !p.Valid() {
			t.Errorf("DefaultParams(%d) is not valid", level)
		}
	}
}

func TestParamsDimensions(t *testing.T) {
	cases := []struct {
		level SecurityLevel
		n     int
		q     int64
	}{
		{Security128, 256, 127},
		{Security192, 384, 251},
		{Security256, 512, 509},
	}
	for _, tc := range cases {
		p := DefaultParams(tc.level)
		if p.N != tc.n {
			t.Errorf("level %d: N = %d, want %d", tc.level, p.N, tc.n)
		}
		if !p.Q.Equal(ratio.FromInt(tc.q)) {
			t.Errorf("level %d: Q = %s, want %d/1", tc.level, p.Q, tc.q)
		}
	}
}

func TestParamsSmoothingLessThanNoise(t *testing.T) {
	for _, level := range []SecurityLevel{Security128, Security192, Security256} {
		p := DefaultParams(level)
		if !p.SmoothingParam.Less(p.NoiseWidth) {
			t.Errorf("level %d: smoothing %s not less than noise %s",
				level, p.SmoothingParam, p.NoiseWidth)
		}
	}
}

func TestParamsNoiseLessThanOne(t *testing.T) {
	for _, level := range []SecurityLevel{Security128, Security192, Security256} {
		p := DefaultParams(level)
		if !p.NoiseWidth.Less(ratio.One) {
			t.Errorf("level %d: noise %s not less than 1", level, p.NoiseWidth)
		}
	}
}

func TestInvalidParams(t *testing.T) {
	cases := []struct {
		name string
		p    Params
	}{
		{"zero N", Params{N: 0, Q: ratio.FromInt(127),
			SmoothingParam: ratio.New(2, 10), NoiseWidth: ratio.New(3, 10),
			MaxWalkSteps: 1000, DissolutionPasses: 2}},
		{"negative N", Params{N: -1, Q: ratio.FromInt(127),
			SmoothingParam: ratio.New(2, 10), NoiseWidth: ratio.New(3, 10),
			MaxWalkSteps: 1000, DissolutionPasses: 2}},
		{"non-integer Q", Params{N: 256, Q: ratio.New(1, 2),
			SmoothingParam: ratio.New(2, 10), NoiseWidth: ratio.New(3, 10),
			MaxWalkSteps: 1000, DissolutionPasses: 2}},
		{"smoothing >= noise", Params{N: 256, Q: ratio.FromInt(127),
			SmoothingParam: ratio.New(5, 10), NoiseWidth: ratio.New(3, 10),
			MaxWalkSteps: 1000, DissolutionPasses: 2}},
		{"noise >= 1", Params{N: 256, Q: ratio.FromInt(127),
			SmoothingParam: ratio.New(2, 10), NoiseWidth: ratio.FromInt(1),
			MaxWalkSteps: 1000, DissolutionPasses: 2}},
		{"zero walk steps", Params{N: 256, Q: ratio.FromInt(127),
			SmoothingParam: ratio.New(2, 10), NoiseWidth: ratio.New(3, 10),
			MaxWalkSteps: 0, DissolutionPasses: 2}},
		{"zero dissolution", Params{N: 256, Q: ratio.FromInt(127),
			SmoothingParam: ratio.New(2, 10), NoiseWidth: ratio.New(3, 10),
			MaxWalkSteps: 1000, DissolutionPasses: 0}},
	}
	for _, tc := range cases {
		if tc.p.Valid() {
			t.Errorf("%s: expected invalid, got valid", tc.name)
		}
	}
}