package main

import (
	"testing"

	intrgb "netdome.biz/paul/impact-80/internal/rgb"
)

func sameZones(a, b []intrgb.Zone) bool {
	if len(a) != len(b) {
		return false
	}
	for i := range a {
		if a[i] != b[i] {
			return false
		}
	}
	return true
}

// README.md: "With `--zone`, commands target exactly the selected zone."
// `save` already honours it, so `load` must not rewrite zones the user did
// not select — otherwise a single-zone restore silently touches all three.
func TestFilterZonesKeepsOnlyTheSelection(t *testing.T) {
	allZones := []intrgb.Zone{intrgb.ZoneLogo, intrgb.ZoneBacklight, intrgb.ZoneSide}

	tests := []struct {
		name     string
		zoneFlag string
		want     []intrgb.Zone
	}{
		{"no flag keeps every zone", "", allZones},
		{"logo keeps logo", "logo", []intrgb.Zone{intrgb.ZoneLogo}},
		{"backlight keeps backlight", "backlight", []intrgb.Zone{intrgb.ZoneBacklight}},
		{"side keeps side", "side", []intrgb.Zone{intrgb.ZoneSide}},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			original := targetZone
			t.Cleanup(func() { targetZone = original })
			targetZone = tt.zoneFlag

			selected, err := selectedZones()
			if err != nil {
				t.Fatalf("selectedZones() returned error: %v", err)
			}

			got := filterZones(allZones, selected)
			if !sameZones(got, tt.want) {
				t.Errorf("filterZones(all, %v) = %v, want %v", selected, got, tt.want)
			}
		})
	}
}

// A profile may omit zones the selection names. Those must not be invented.
func TestFilterZonesDoesNotAddMissingZones(t *testing.T) {
	original := targetZone
	t.Cleanup(func() { targetZone = original })
	targetZone = "backlight"

	profileZones := []intrgb.Zone{intrgb.ZoneSide}

	selected, err := selectedZones()
	if err != nil {
		t.Fatalf("selectedZones() returned error: %v", err)
	}

	got := filterZones(profileZones, selected)
	if len(got) != 0 {
		t.Errorf("filterZones(side-only profile, backlight) = %v, want empty", got)
	}
}

// filterZones must not reorder or mutate its input.
func TestFilterZonesDoesNotMutateInput(t *testing.T) {
	original := targetZone
	t.Cleanup(func() { targetZone = original })
	targetZone = "logo"

	input := []intrgb.Zone{intrgb.ZoneSide, intrgb.ZoneLogo}
	selected, err := selectedZones()
	if err != nil {
		t.Fatalf("selectedZones() returned error: %v", err)
	}

	filterZones(input, selected)

	if !sameZones(input, []intrgb.Zone{intrgb.ZoneSide, intrgb.ZoneLogo}) {
		t.Errorf("filterZones() mutated its input: %v", input)
	}
}