package main

import (
	"path/filepath"
	"testing"

	"github.com/stretchr/testify/require"
)

func TestViewLayoutKeepsTheMessagesItSent(t *testing.T) {
	path := filepath.Join(t.TempDir(), viewLayoutFileName)
	layout, err := loadViewLayout(path)
	require.NoError(t, err)

	texts, err := layout.Split(nil)
	require.NoError(t, err)
	require.Equal(t, []string{"<chat>\n"}, texts)

	texts, err = layout.Split([]string{"0+1|a\n", "1+1|b\n"})
	require.NoError(t, err)
	require.Equal(t, []string{"<chat>\n", "0+1|a\n1+1|b\n"}, texts)

	// The same lines give the same messages, also after a restart.
	layout, err = loadViewLayout(path)
	require.NoError(t, err)

	texts, err = layout.Split([]string{"0+1|a\n", "1+1|b\n"})
	require.NoError(t, err)
	require.Equal(t, []string{"<chat>\n", "0+1|a\n1+1|b\n"}, texts)

	texts, err = layout.Split([]string{"0+1|a\n", "1+1|b\n", "2+1|c\n"})
	require.NoError(t, err)
	require.Equal(t, []string{"<chat>\n", "0+1|a\n1+1|b\n", "2+1|c\n"}, texts)
}

func TestViewLayoutStartsAgainAtAChangedMessage(t *testing.T) {
	layout, err := loadViewLayout(filepath.Join(t.TempDir(), viewLayoutFileName))
	require.NoError(t, err)

	_, err = layout.Split([]string{"0+1|a\n"})
	require.NoError(t, err)

	_, err = layout.Split([]string{"0+1|a\n", "1+1|b\n", "2+1|c\n"})
	require.NoError(t, err)

	// A batch merges lines 1 and 2, so the second message changes, and the
	// rest becomes one new message.
	texts, err := layout.Split([]string{"0+1|a\n", "1+2|b c\n", "3+1|d\n"})
	require.NoError(t, err)
	require.Equal(t, []string{"<chat>\n0+1|a\n", "1+2|b c\n3+1|d\n"}, texts)

	// A view that lost lines starts again with one message.
	texts, err = layout.Split([]string{"0+4|all\n"})
	require.NoError(t, err)
	require.Equal(t, []string{"<chat>\n0+4|all\n"}, texts)
}