package main

import (
	"bytes"
	"errors"
	"strings"
	"testing"

	intrgb "netdome.biz/paul/qmk-rgb/internal/rgb"
	"netdome.biz/paul/qmk-rgb/internal/via"
)

// verifyingProtocol records writes and reports what the keyboard actually
// applied, which on real hardware is not always the requested value.
type verifyingProtocol struct {
	reports  []commandReport
	applied  map[via.Channel]uint8
	channels []via.Channel
	getErr   error
	getCalls int
}

// impact80Display is the channel naming the Impact 80's definition file
// supplies, so summary lines name logo, backlight and side.
func impact80Display() map[uint16]string {
	return map[uint16]string{2: "logo", 3: "backlight", 4: "side"}
}

func impact80Channels() []via.Channel {
	return []via.Channel{via.ChannelRgblight, via.ChannelRgbMatrix, via.ChannelAudio}
}

// DetectChannels reports the three channels of the board under test unless a
// test asks for a different set.
func (f *verifyingProtocol) DetectChannels() ([]via.Channel, error) {
	if f.channels == nil {
		return []via.Channel{via.ChannelRgblight, via.ChannelRgbMatrix, via.ChannelAudio}, nil
	}
	return f.channels, nil
}

func (f *verifyingProtocol) SetValue(channel via.Channel, param, value uint8) error {
	f.reports = append(f.reports, commandReport{channel: channel, param: param, value: value})
	return nil
}

func (f *verifyingProtocol) SetColor(via.Channel, uint8, uint8) error { return nil }

func (f *verifyingProtocol) GetValue(channel via.Channel, param uint8) ([]byte, error) {
	f.getCalls++
	if f.getErr != nil {
		return nil, f.getErr
	}
	// The color value ID is two bytes; a one byte answer would make every
	// caller that reads a colour fail for the wrong reason.
	if param == uint8(intrgb.ColorValue) {
		return []byte{f.applied[channel], 255}, nil
	}
	return []byte{f.applied[channel]}, nil
}

func (f *verifyingProtocol) Close() error { return nil }

func appliedFor(p *verifyingProtocol, channel via.Channel) uint8 { return p.applied[channel] }

func TestSetBrightnessVerifiedReportsAppliedValue(t *testing.T) {
	tests := []struct {
		name        string
		requested   uint8
		applied     uint8
		wantWarning bool
	}{
		{"keyboard honours the value", 100, 100, false},
		{"keyboard clamps to 160", 200, 160, true},
		{"keyboard scales up", 100, 159, true},
		{"both zones clamp", 255, 160, true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			proto := &verifyingProtocol{
				applied: map[via.Channel]uint8{
					via.ChannelRgblight:  tt.applied,
					via.ChannelRgbMatrix: tt.applied,
					via.ChannelAudio:     tt.applied,
				},
			}

			zones := []via.Channel{via.ChannelRgblight}
			results, err := setBrightnessVerified(proto, zones, impact80Display(), tt.requested)
			if err != nil {
				t.Fatalf("setBrightnessVerified() error = %v", err)
			}
			if len(results) != 1 {
				t.Fatalf("results = %d entries, want 1", len(results))
			}

			got := results[0]
			if got.Name != "logo" {
				t.Errorf("results[0].Name = %q, want %q", got.Name, "logo")
			}
			if got.Requested != tt.requested {
				t.Errorf("results[0].Requested = %d, want %d", got.Requested, tt.requested)
			}
			if got.Applied != tt.applied {
				t.Errorf("results[0].Applied = %d, want %d", got.Applied, tt.applied)
			}
			if got.Mismatch() != tt.wantWarning {
				t.Errorf("results[0].Mismatch() = %t, want %t", got.Mismatch(), tt.wantWarning)
			}
		})
	}
}

// The read-back must happen once per written zone, on the right channel.
func TestSetBrightnessVerifiedReadsBackEveryZone(t *testing.T) {
	proto := &verifyingProtocol{
		applied: map[via.Channel]uint8{
			via.ChannelRgblight:  160,
			via.ChannelRgbMatrix: 255,
			via.ChannelAudio:     160,
		},
	}

	results, err := setBrightnessVerified(proto, impact80Channels(), impact80Display(), 200)
	if err != nil {
		t.Fatalf("setBrightnessVerified() error = %v", err)
	}
	if len(results) != 3 {
		t.Fatalf("results = %d entries, want 3", len(results))
	}
	if proto.getCalls != 3 {
		t.Errorf("GetValue calls = %d, want 3", proto.getCalls)
	}

	// A set that fails must not be reported as applied.
	if got := appliedFor(proto, via.ChannelRgblight); got != 160 {
		t.Errorf("unexpected applied value %d", got)
	}

	want := map[string]uint8{
		"logo":      160,
		"backlight": 255,
		"side":      160,
	}
	for _, r := range results {
		if r.Applied != want[r.Name] {
			t.Errorf("%s applied = %d, want %d", r.Name, r.Applied, want[r.Name])
		}
		if !r.Mismatch() {
			t.Errorf("%s: Mismatch() = false, want true (requested 200)", r.Name)
		}
	}
}

// A failed read-back must not be silently reported as success.
func TestSetBrightnessVerifiedPropagatesReadError(t *testing.T) {
	proto := &verifyingProtocol{getErr: errors.New("read timeout")}

	if _, err := setBrightnessVerified(proto, []via.Channel{via.ChannelRgblight}, impact80Display(), 100); err == nil {
		t.Fatal("setBrightnessVerified() expected read error, got nil")
	}
}

func TestBrightnessCommandStaysQuietWhenApplied(t *testing.T) {
	proto := &verifyingProtocol{applied: map[via.Channel]uint8{via.ChannelRgblight: 200}}

	t.Cleanup(impact80Target(t, proto))

	var out, errOut bytes.Buffer
	cmd := NewBrightnessCmd()
	cmd.SetOut(&out)
	cmd.SetErr(&errOut)
	cmd.SetArgs([]string{"200"})

	if err := cmd.Execute(); err != nil {
		t.Fatalf("brightness returned error: %v", err)
	}

	if errOut.Len() != 0 {
		t.Errorf("stderr = %q, want no warning when the keyboard applied the requested value", errOut.String())
	}
	if !strings.Contains(out.String(), "200") {
		t.Errorf("stdout = %q, want the applied value reported", out.String())
	}
}