package web

import (
	"fmt"
	"os"
	"path/filepath"
	"testing"
	"time"

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

func TestListConfigBackupsNewestFirst(t *testing.T) {
	dir := t.TempDir()
	older := filepath.Join(dir, "2026-01-01-000000_mpv.conf")
	newer := filepath.Join(dir, "2026-01-02-000000_mpv.conf")
	other := filepath.Join(dir, "notes.txt")
	require.NoError(t, os.WriteFile(older, []byte("old"), 0600))
	require.NoError(t, os.WriteFile(newer, []byte("new"), 0600))
	require.NoError(t, os.WriteFile(other, []byte("x"), 0600))

	oldTime := time.Date(2026, 1, 1, 0, 0, 0, 0, time.Local)
	newTime := time.Date(2026, 1, 2, 0, 0, 0, 0, time.Local)
	require.NoError(t, os.Chtimes(older, oldTime, oldTime))
	require.NoError(t, os.Chtimes(newer, newTime, newTime))

	backups := listConfigBackups(dir)
	require.Len(t, backups, 2)
	assert.Equal(t, "2026-01-02-000000_mpv.conf", backups[0].Filename)
	assert.Equal(t, filepath.Join(dir, "2026-01-02-000000_mpv.conf"), backups[0].FilePath)
	assert.Equal(t, newTime.Format("2006-01-02 15:04:05"), backups[0].CreatedDate)
	assert.Equal(t, "2026-01-01-000000_mpv.conf", backups[1].Filename)
}

func TestListConfigBackupsMissingDir(t *testing.T) {
	backups := listConfigBackups(filepath.Join(t.TempDir(), "does-not-exist"))
	assert.Empty(t, backups)
}

func TestListConfigBackupsIgnoresNonRegularConfEntries(t *testing.T) {
	dir := t.TempDir()
	realBackup := filepath.Join(dir, "real.conf")
	require.NoError(t, os.WriteFile(realBackup, []byte("backup"), 0600))
	require.NoError(t, os.Mkdir(filepath.Join(dir, "directory.conf"), 0700))
	if err := os.Symlink(realBackup, filepath.Join(dir, "link.conf")); err != nil {
		t.Skipf("symlinks unavailable: %v", err)
	}

	backups := listConfigBackups(dir)
	require.Len(t, backups, 1)
	assert.Equal(t, "real.conf", backups[0].Filename)
}

func TestBuildConfigBackupsListDataPaginates(t *testing.T) {
	backups := make([]ConfigBackup, 25)
	for i := range backups {
		backups[i] = ConfigBackup{Filename: fmt.Sprintf("backup-%02d.conf", i)}
	}

	first := buildConfigBackupsListData(backups, "", 0)
	assert.Len(t, first.ConfigBackups, configBackupsPageSize)
	assert.Equal(t, 25, first.Total)
	assert.Equal(t, 12, first.VisibleEnd)
	assert.Equal(t, 12, first.NextOffset)
	assert.True(t, first.HasMore)

	last := buildConfigBackupsListData(backups, "", 24)
	require.Len(t, last.ConfigBackups, 1)
	assert.Equal(t, "backup-24.conf", last.ConfigBackups[0].Filename)
	assert.Equal(t, 25, last.VisibleEnd)
	assert.False(t, last.HasMore)
}

func TestBuildConfigBackupsListDataSearchesMetadata(t *testing.T) {
	backups := []ConfigBackup{
		{Filename: "alpha.conf", CreatedDate: "2026-01-02 00:00:00", FilePath: "/tmp/alpha.conf"},
		{Filename: "beta.conf", CreatedDate: "2026-03-04 00:00:00", FilePath: "/archive/special/beta.conf"},
	}

	byDate := buildConfigBackupsListData(backups, "03-04", 0)
	require.Len(t, byDate.ConfigBackups, 1)
	assert.Equal(t, "beta.conf", byDate.ConfigBackups[0].Filename)
	assert.Equal(t, 2, byDate.AllTotal)

	byPath := buildConfigBackupsListData(backups, "SPECIAL", 0)
	require.Len(t, byPath.ConfigBackups, 1)
	assert.Equal(t, "beta.conf", byPath.ConfigBackups[0].Filename)

	beyondEnd := buildConfigBackupsListData(backups, "", 99)
	assert.Empty(t, beyondEnd.ConfigBackups)
	assert.Equal(t, 2, beyondEnd.VisibleEnd)
}