package m31

import (
	"encoding/json"
	"errors"
	"testing"
	"testing/synctest"
	"time"

	"github.com/stretchr/testify/require"

	"onehouse/protocol"
)

func TestConnectionBaselineAndInputEvents(t *testing.T) {
	synctest.Test(t, func(t *testing.T) {
		c, client, transport := testConnection(t)
		require.Empty(t, transport.ofKind(protocol.Event))

		client.inputs[0], client.inputs[15] = true, true
		client.inputDelay = time.Millisecond
		observedAt := time.Now().Add(time.Millisecond).UTC()

		require.NoError(t, c.poll(t.Context()))

		events := transport.ofKind(protocol.Event)
		require.Len(t, events, 2)

		for _, event := range events {
			require.Equal(t, &observedAt, event.Metadata.SentAt)
			require.JSONEq(t, `{"action":"pressed","value":true}`, eventJSON(t, event.Payload))
		}

		require.NoError(t, c.poll(t.Context()))
		require.Len(t, transport.ofKind(protocol.Event), 2)

		client.inputs[0] = false

		require.NoError(t, c.poll(t.Context()))

		events = transport.ofKind(protocol.Event)
		require.Len(t, events, 3)
		require.JSONEq(t, `{"action":"released","value":false}`, eventJSON(t, events[2].Payload))

		client.coils[2] = true
		transport.messages = nil

		require.NoError(t, c.poll(t.Context()))
		require.Empty(t, transport.messages)
	})
}

func TestConnectionRejectsConfigurationAndReadFailuresBeforeOnline(t *testing.T) {
	testCases := []struct {
		name   string
		change func(*fakeClient)
	}{
		{name: "rejects pulse register write failure", change: func(c *fakeClient) {
			c.registerErr = errors.New("configuration failed")
		}},
		{name: "rejects configuration mismatch", change: func(c *fakeClient) {
			c.wrongConfig = true
		}},
		{name: "rejects input read failure", change: func(c *fakeClient) {
			c.inputErr = errors.New("input read failed")
		}},
		{name: "rejects coil read failure", change: func(c *fakeClient) {
			c.readErr = errors.New("coil read failed")
		}},
		{name: "rejects incomplete read", change: func(c *fakeClient) {
			c.shortRead = true
		}},
		{name: "rejects unsafe voltage", change: func(c *fakeClient) {
			c.analog[0] = 10001
		}},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			d, client, transport := testAssembly(t)
			tc.change(client)

			c := &connection{owner: d}
			err := c.start(t.Context())

			var failure *deviceError

			require.ErrorAs(t, err, &failure)
			require.Empty(t, transport.messages)
		})
	}
}

func TestConnectionReturnsPublicationFailures(t *testing.T) {
	testCases := []struct {
		name   string
		kind   protocol.Kind
		change func(*fakeClient)
	}{
		{name: "returns input report failure", kind: protocol.Reported, change: func(c *fakeClient) {
			c.inputs[0] = true
		}},
		{name: "returns transition failure", kind: protocol.Event, change: func(c *fakeClient) {
			c.inputs[0] = true
		}},
		{name: "returns output report failure", kind: protocol.Reported, change: func(c *fakeClient) {
			c.coils[0] = true
		}},
		{name: "returns voltage report failure", kind: protocol.Reported, change: func(c *fakeClient) {
			c.analog[0] = 5000
		}},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			c, client, transport := testConnection(t)
			failure := errors.New("publish failed")
			transport.failKind, transport.err = tc.kind, failure
			tc.change(client)
			require.ErrorIs(t, c.poll(t.Context()), failure)
		})
	}
}

func eventJSON(t *testing.T, value any) string {
	t.Helper()

	data, err := json.Marshal(value)
	require.NoError(t, err)

	return string(data)
}