package stats

import (
	"encoding/json"
	"testing"

	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
)

func TestPureHydrogenModeFromEnvelope(t *testing.T) {
	tests := []struct {
		name   string
		env    envelope.FrameEnvelope
		active bool
		known  bool
	}{
		{
			name:   "gb32960 fuel cell mode",
			env:    envelope.FrameEnvelope{Protocol: envelope.ProtocolGB32960, Fields: map[string]any{envelope.FieldFuelCellWorkMode: 2}},
			active: true,
			known:  true,
		},
		{
			name:  "gb32960 electric mode",
			env:   envelope.FrameEnvelope{Protocol: envelope.ProtocolGB32960, Fields: map[string]any{envelope.FieldFuelCellWorkMode: 1}},
			known: true,
		},
		{
			name:   "yutong active mode",
			env:    envelope.FrameEnvelope{Protocol: envelope.ProtocolYutongMQTT, Fields: map[string]any{envelope.FieldFuelCellWorkMode: json.Number("4")}},
			active: true,
			known:  true,
		},
		{
			name:   "yutong driving mode",
			env:    envelope.FrameEnvelope{Protocol: envelope.ProtocolYutongMQTT, Fields: map[string]any{envelope.FieldFuelCellWorkMode: "11"}},
			active: true,
			known:  true,
		},
		{
			name:  "yutong inactive mode",
			env:   envelope.FrameEnvelope{Protocol: envelope.ProtocolYutongMQTT, Fields: map[string]any{envelope.FieldFuelCellWorkMode: float64(1)}},
			known: true,
		},
		{
			name: "unknown yutong mode",
			env:  envelope.FrameEnvelope{Protocol: envelope.ProtocolYutongMQTT, Fields: map[string]any{envelope.FieldFuelCellWorkMode: 9}},
		},
		{
			name: "unsupported protocol",
			env:  envelope.FrameEnvelope{Protocol: envelope.ProtocolJT808, Fields: map[string]any{envelope.FieldFuelCellWorkMode: 3}},
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			active, known := PureHydrogenModeFromEnvelope(test.env)
			if active != test.active || known != test.known {
				t.Fatalf("PureHydrogenModeFromEnvelope() = (%v, %v), want (%v, %v)", active, known, test.active, test.known)
			}
		})
	}
}

func TestPureHydrogenMileageDeltaRequiresContinuousKnownActiveMode(t *testing.T) {
	tests := []struct {
		name                          string
		previousKM, currentKM         float64
		previousActive, previousKnown bool
		currentActive, currentKnown   bool
		want                          float64
	}{
		{
			name:           "continuous active interval",
			previousKM:     100,
			currentKM:      106.5,
			previousActive: true,
			previousKnown:  true,
			currentActive:  true,
			currentKnown:   true,
			want:           6.5,
		},
		{
			name:          "transition into active is unclassified",
			previousKM:    100,
			currentKM:     106.5,
			previousKnown: true,
			currentActive: true,
			currentKnown:  true,
		},
		{
			name:           "unknown endpoint is unclassified",
			previousKM:     100,
			currentKM:      106.5,
			previousActive: true,
			previousKnown:  true,
			currentActive:  true,
		},
		{
			name:           "odometer rollback is rejected",
			previousKM:     106.5,
			currentKM:      100,
			previousActive: true,
			previousKnown:  true,
			currentActive:  true,
			currentKnown:   true,
		},
		{
			name:           "implausible jump is rejected",
			previousKM:     100,
			currentKM:      2601,
			previousActive: true,
			previousKnown:  true,
			currentActive:  true,
			currentKnown:   true,
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			got := PureHydrogenMileageDelta(
				test.previousKM,
				test.currentKM,
				test.previousActive,
				test.previousKnown,
				test.currentActive,
				test.currentKnown,
			)
			if got != test.want {
				t.Fatalf("PureHydrogenMileageDelta() = %v, want %v", got, test.want)
			}
		})
	}
}