path: root/internal/reports/timesheet_test.go

package reports

import (
	"database/sql"
	"os"
	"os/exec"
	"path/filepath"
	"testing"
	"time"

	"git.tjp.lol/punchcard/internal/queries"
	"git.tjp.lol/punchcard/templates"
)

func TestGenerateTimesheetData(t *testing.T) {
	tests := []struct {
		name        string
		entries     interface{}
		clientID    int64
		clientName  string
		projectName string
		contractor  queries.Contractor
		dateRange   DateRange
		timezone    *time.Location
		wantEntries int
		wantHours   float64
		wantError   bool
	}{
		{
			name: "client entries with UTC timezone",
			entries: []queries.GetTimesheetDataByClientRow{
				{
					TimeEntryID:     1,
					StartTime:       mustParseTime("2025-07-10T14:55:00Z"),
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-10T18:05:00Z"), Valid: true},
					Description:     sql.NullString{String: "GL closing", Valid: true},
					DurationSeconds: 11400, // 3:10
				},
				{
					TimeEntryID:     2,
					StartTime:       mustParseTime("2025-07-10T18:42:00Z"),
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-10T20:04:00Z"), Valid: true},
					Description:     sql.NullString{String: "GL closing", Valid: true},
					DurationSeconds: 4920, // 1:22
				},
			},
			clientID:   1,
			clientName: "Test Client",
			contractor: queries.Contractor{
				Name:  "Travis Parker",
				Label: "Software Development",
				Email: "travis@example.com",
			},
			dateRange: DateRange{
				Start: mustParseTime("2025-07-01T00:00:00Z"),
				End:   mustParseTime("2025-07-31T23:59:59Z"),
			},
			timezone:    time.UTC,
			wantEntries: 2,
			wantHours:   4.5333, // 16320 seconds / 3600
		},
		{
			name: "project entries with local timezone",
			entries: []queries.GetTimesheetDataByProjectRow{
				{
					TimeEntryID:     3,
					StartTime:       mustParseTime("2025-07-11T13:55:00Z"),
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-11T18:35:00Z"), Valid: true},
					Description:     sql.NullString{String: "Development work", Valid: true},
					ProjectID:       1,
					ProjectName:     "Test Project",
					DurationSeconds: 16800, // 4:40
				},
			},
			clientID:    1,
			clientName:  "Test Client",
			projectName: "Test Project",
			contractor: queries.Contractor{
				Name:  "Travis Parker",
				Label: "Software Development",
				Email: "travis@example.com",
			},
			dateRange: DateRange{
				Start: mustParseTime("2025-07-01T00:00:00Z"),
				End:   mustParseTime("2025-07-31T23:59:59Z"),
			},
			timezone:    time.Local,
			wantEntries: 1,
			wantHours:   4.6667, // 16800 seconds / 3600
		},
		{
			name: "entries with different timezone",
			entries: []queries.GetTimesheetDataByClientRow{
				{
					TimeEntryID:     4,
					StartTime:       mustParseTime("2025-07-15T00:09:00Z"),
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-15T00:13:00Z"), Valid: true},
					Description:     sql.NullString{String: "Quick fix", Valid: true},
					DurationSeconds: 240, // 4 minutes
				},
			},
			clientID:   1,
			clientName: "Test Client",
			contractor: queries.Contractor{
				Name:  "Travis Parker",
				Label: "Software Development",
				Email: "travis@example.com",
			},
			dateRange: DateRange{
				Start: mustParseTime("2025-07-01T00:00:00Z"),
				End:   mustParseTime("2025-07-31T23:59:59Z"),
			},
			timezone:    mustLoadLocation("America/New_York"),
			wantEntries: 1,
			wantHours:   0.0667, // 240 seconds / 3600
		},
		{
			name:      "unsupported entry type",
			entries:   "invalid",
			wantError: true,
		},
		{
			name: "entries with Pacific timezone (UTC-8)",
			entries: []queries.GetTimesheetDataByClientRow{
				{
					TimeEntryID:     5,
					StartTime:       mustParseTime("2025-07-15T08:00:00Z"), // 8 AM UTC = midnight PST
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-15T16:00:00Z"), Valid: true}, // 4 PM UTC = 8 AM PST
					Description:     sql.NullString{String: "Early morning work", Valid: true},
					DurationSeconds: 28800, // 8 hours
				},
			},
			clientID:   1,
			clientName: "Test Client",
			contractor: queries.Contractor{
				Name:  "Travis Parker",
				Label: "Software Development", 
				Email: "travis@example.com",
			},
			dateRange: DateRange{
				Start: mustParseTime("2025-07-01T00:00:00Z"),
				End:   mustParseTime("2025-07-31T23:59:59Z"),
			},
			timezone:    mustLoadLocation("America/Los_Angeles"),
			wantEntries: 1,
			wantHours:   8.0,
		},
		{
			name: "entries crossing date boundary in timezone",
			entries: []queries.GetTimesheetDataByClientRow{
				{
					TimeEntryID:     6,
					StartTime:       mustParseTime("2025-07-15T23:30:00Z"), // 11:30 PM UTC = 4:30 PM PDT (July 15)
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-16T01:30:00Z"), Valid: true}, // 1:30 AM UTC = 6:30 PM PDT (July 15, same day in PDT)
					Description:     sql.NullString{String: "Late evening work", Valid: true},
					DurationSeconds: 7200, // 2 hours
				},
			},
			clientID:   1,
			clientName: "Test Client",
			contractor: queries.Contractor{
				Name:  "Travis Parker",
				Label: "Software Development",
				Email: "travis@example.com",
			},
			dateRange: DateRange{
				Start: mustParseTime("2025-07-01T00:00:00Z"),
				End:   mustParseTime("2025-07-31T23:59:59Z"),
			},
			timezone:    mustLoadLocation("America/Los_Angeles"),
			wantEntries: 1,
			wantHours:   2.0,
		},
		{
			name: "entries with extreme positive timezone (UTC+14)",
			entries: []queries.GetTimesheetDataByClientRow{
				{
					TimeEntryID:     7,
					StartTime:       mustParseTime("2025-07-15T10:00:00Z"), // 10 AM UTC = midnight+1day in UTC+14
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-15T12:00:00Z"), Valid: true}, // 12 PM UTC = 2 AM+1day in UTC+14
					Description:     sql.NullString{String: "Future timezone work", Valid: true},
					DurationSeconds: 7200, // 2 hours
				},
			},
			clientID:   1,
			clientName: "Test Client",
			contractor: queries.Contractor{
				Name:  "Travis Parker",
				Label: "Software Development",
				Email: "travis@example.com",
			},
			dateRange: DateRange{
				Start: mustParseTime("2025-07-01T00:00:00Z"),
				End:   mustParseTime("2025-07-31T23:59:59Z"),
			},
			timezone:    time.FixedZone("UTC+14", 14*3600),
			wantEntries: 1,
			wantHours:   2.0,
		},
		{
			name: "entries with extreme negative timezone (UTC-12)",
			entries: []queries.GetTimesheetDataByClientRow{
				{
					TimeEntryID:     8,
					StartTime:       mustParseTime("2025-07-15T12:00:00Z"), // 12 PM UTC = midnight in UTC-12
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-15T15:00:00Z"), Valid: true}, // 3 PM UTC = 3 AM in UTC-12
					Description:     sql.NullString{String: "Early timezone work", Valid: true},
					DurationSeconds: 10800, // 3 hours
				},
			},
			clientID:   1,
			clientName: "Test Client",
			contractor: queries.Contractor{
				Name:  "Travis Parker",
				Label: "Software Development",
				Email: "travis@example.com",
			},
			dateRange: DateRange{
				Start: mustParseTime("2025-07-01T00:00:00Z"),
				End:   mustParseTime("2025-07-31T23:59:59Z"),
			},
			timezone:    time.FixedZone("UTC-12", -12*3600),
			wantEntries: 1,
			wantHours:   3.0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result, err := GenerateTimesheetData(
				tt.entries,
				tt.clientID,
				tt.clientName,
				tt.projectName,
				tt.contractor,
				tt.dateRange,
				tt.timezone,
			)

			if tt.wantError {
				if err == nil {
					t.Errorf("GenerateTimesheetData() expected error but got none")
				}
				return
			}

			if err != nil {
				t.Errorf("GenerateTimesheetData() error = %v", err)
				return
			}

			if len(result.Entries) != tt.wantEntries {
				t.Errorf("GenerateTimesheetData() entries count = %d, want %d", len(result.Entries), tt.wantEntries)
			}

			// Check total hours (with tolerance for floating point precision)
			if abs(result.TotalHours-tt.wantHours) > 0.001 {
				t.Errorf("GenerateTimesheetData() total hours = %f, want %f", result.TotalHours, tt.wantHours)
			}

			// Check basic fields
			if result.ClientID != tt.clientID {
				t.Errorf("GenerateTimesheetData() client ID = %d, want %d", result.ClientID, tt.clientID)
			}
			if result.ClientName != tt.clientName {
				t.Errorf("GenerateTimesheetData() client name = %s, want %s", result.ClientName, tt.clientName)
			}
			if result.ProjectName != tt.projectName {
				t.Errorf("GenerateTimesheetData() project name = %s, want %s", result.ProjectName, tt.projectName)
			}

			// Check timezone handling
			if tt.timezone != nil {
				expectedTimezone := tt.timezone.String()
				if expectedTimezone == "Local" {
					zone, _ := time.Now().Zone()
					expectedTimezone = zone
				}
				if result.Timezone != expectedTimezone {
					t.Errorf("GenerateTimesheetData() timezone = %s, want %s", result.Timezone, expectedTimezone)
				}
			}
		})
	}
}

func TestConvertToTimesheetEntries(t *testing.T) {
	tests := []struct {
		name     string
		entries  []timesheetEntryData
		timezone *time.Location
		want     []TimesheetEntry
	}{
		{
			name: "UTC timezone conversion",
			entries: []timesheetEntryData{
				{
					TimeEntryID:     1,
					StartTime:       mustParseTime("2025-07-10T14:55:00Z"),
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-10T18:05:00Z"), Valid: true},
					Description:     sql.NullString{String: "Development work", Valid: true},
					ProjectName:     sql.NullString{String: "Test Project", Valid: true},
					DurationSeconds: 11400, // 3:10
				},
			},
			timezone: time.UTC,
			want: []TimesheetEntry{
				{
					Date:        "2025-07-10",
					StartTime:   "14:55",
					EndTime:     "18:05",
					Duration:    "3:10",
					Hours:       3.1667, // Rounded to nearest minute
					ProjectName: "Test Project",
					Description: "Development work",
				},
			},
		},
		{
			name: "timezone conversion to EST",
			entries: []timesheetEntryData{
				{
					TimeEntryID:     2,
					StartTime:       mustParseTime("2025-07-10T18:00:00Z"),                                  // 6:00 PM UTC
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-10T19:00:00Z"), Valid: true}, // 7:00 PM UTC
					Description:     sql.NullString{String: "Meeting", Valid: true},
					DurationSeconds: 3600, // 1 hour
				},
			},
			timezone: mustLoadLocation("America/New_York"), // UTC-4 in July (EDT)
			want: []TimesheetEntry{
				{
					Date:        "2025-07-10",
					StartTime:   "14:00", // 2:00 PM EDT
					EndTime:     "15:00", // 3:00 PM EDT
					Duration:    "1:00",
					Hours:       1.0,
					ProjectName: "",
					Description: "Meeting",
				},
			},
		},
		{
			name: "skip entry without end time",
			entries: []timesheetEntryData{
				{
					TimeEntryID:     3,
					StartTime:       mustParseTime("2025-07-10T14:55:00Z"),
					EndTime:         sql.NullTime{Valid: false}, // No end time
					Description:     sql.NullString{String: "Active entry", Valid: true},
					DurationSeconds: 0,
				},
			},
			timezone: time.UTC,
			want:     []TimesheetEntry{}, // Should be empty
		},
		{
			name: "entry crossing midnight boundary in Pacific timezone",
			entries: []timesheetEntryData{
				{
					TimeEntryID:     4,
					StartTime:       mustParseTime("2025-07-15T23:00:00Z"), // 11 PM UTC = 4 PM PDT (July 15)
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-16T03:00:00Z"), Valid: true}, // 3 AM UTC = 8 PM PDT (July 15)
					Description:     sql.NullString{String: "Evening work", Valid: true},
					DurationSeconds: 14400, // 4 hours
				},
			},
			timezone: mustLoadLocation("America/Los_Angeles"),
			want: []TimesheetEntry{
				{
					Date:        "2025-07-15", // Should be July 15 in PDT despite UTC crossing midnight
					StartTime:   "16:00",      // 4:00 PM PDT
					EndTime:     "20:00",      // 8:00 PM PDT
					Duration:    "4:00",
					Hours:       4.0,
					ProjectName: "",
					Description: "Evening work",
				},
			},
		},
		{
			name: "entry in extreme timezone (UTC+14)",
			entries: []timesheetEntryData{
				{
					TimeEntryID:     5,
					StartTime:       mustParseTime("2025-07-15T10:00:00Z"), // 10 AM UTC = midnight next day in UTC+14
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-15T13:00:00Z"), Valid: true}, // 1 PM UTC = 3 AM next day in UTC+14
					Description:     sql.NullString{String: "Future timezone work", Valid: true},
					DurationSeconds: 10800, // 3 hours
				},
			},
			timezone: time.FixedZone("UTC+14", 14*3600),
			want: []TimesheetEntry{
				{
					Date:        "2025-07-16", // Next day in UTC+14
					StartTime:   "00:00",      // Midnight
					EndTime:     "03:00",      // 3 AM
					Duration:    "3:00",
					Hours:       3.0,
					ProjectName: "",
					Description: "Future timezone work",
				},
			},
		},
		{
			name: "entry spanning DST transition (spring forward)",
			entries: []timesheetEntryData{
				{
					TimeEntryID:     6,
					StartTime:       mustParseTime("2024-03-10T06:30:00Z"), // 1:30 AM EST, before DST
					EndTime:         sql.NullTime{Time: mustParseTime("2024-03-10T10:30:00Z"), Valid: true}, // 5:30 AM EST/6:30 AM EDT after DST
					Description:     sql.NullString{String: "DST transition work", Valid: true},
					DurationSeconds: 14400, // 4 hours
				},
			},
			timezone: mustLoadLocation("America/New_York"),
			want: []TimesheetEntry{
				{
					Date:        "2024-03-10",
					StartTime:   "01:30", // EST time before spring forward
					EndTime:     "06:30", // EDT time after spring forward (skips 2-3 AM)
					Duration:    "4:00",  // Duration is still 4 hours
					Hours:       4.0,
					ProjectName: "",
					Description: "DST transition work",
				},
			},
		},
		{
			name: "rounding to nearest minute",
			entries: []timesheetEntryData{
				{
					TimeEntryID:     7,
					StartTime:       mustParseTime("2025-07-10T14:00:00Z"),
					EndTime:         sql.NullTime{Time: mustParseTime("2025-07-10T15:01:29Z"), Valid: true}, // 1 hour 1 minute 29 seconds
					Description:     sql.NullString{String: "Rounding test", Valid: true},
					DurationSeconds: 3689, // 1:01:29
				},
			},
			timezone: time.UTC,
			want: []TimesheetEntry{
				{
					Date:        "2025-07-10",
					StartTime:   "14:00",
					EndTime:     "15:01",
					Duration:    "1:01", // Rounds down to 61 minutes
					Hours:       1.0167, // (3689+30)/60 = 3719 seconds = 61.9833 minutes = 1.0331 hours rounded to nearest minute
					ProjectName: "",
					Description: "Rounding test",
				},
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := convertToTimesheetEntries(tt.entries, tt.timezone)

			if len(result) != len(tt.want) {
				t.Errorf("convertToTimesheetEntries() length = %d, want %d", len(result), len(tt.want))
				return
			}

			for i, entry := range result {
				want := tt.want[i]
				if entry.Date != want.Date {
					t.Errorf("entry[%d].Date = %s, want %s", i, entry.Date, want.Date)
				}
				if entry.StartTime != want.StartTime {
					t.Errorf("entry[%d].StartTime = %s, want %s", i, entry.StartTime, want.StartTime)
				}
				if entry.EndTime != want.EndTime {
					t.Errorf("entry[%d].EndTime = %s, want %s", i, entry.EndTime, want.EndTime)
				}
				if entry.Duration != want.Duration {
					t.Errorf("entry[%d].Duration = %s, want %s", i, entry.Duration, want.Duration)
				}
				if abs(entry.Hours-want.Hours) > 0.001 {
					t.Errorf("entry[%d].Hours = %f, want %f", i, entry.Hours, want.Hours)
				}
				if entry.ProjectName != want.ProjectName {
					t.Errorf("entry[%d].ProjectName = %s, want %s", i, entry.ProjectName, want.ProjectName)
				}
				if entry.Description != want.Description {
					t.Errorf("entry[%d].Description = %s, want %s", i, entry.Description, want.Description)
				}
			}
		})
	}
}

func TestFormatDuration(t *testing.T) {
	tests := []struct {
		name    string
		seconds int64
		want    string
	}{
		{"zero", 0, "0:00"},
		{"30 seconds (rounds down)", 30, "0:01"}, // 30 seconds rounds to 1 minute
		{"29 seconds (rounds down)", 29, "0:00"}, // 29 seconds rounds to 0 minutes
		{"90 seconds", 90, "0:02"},               // 90 seconds rounds to 2 minutes
		{"1 hour", 3600, "1:00"},
		{"1 hour 30 minutes", 5400, "1:30"},
		{"1 hour 29 minutes 59 seconds", 5399, "1:30"}, // Rounds to 1:30
		{"3 hours 10 minutes", 11400, "3:10"},
		{"large duration", 50000, "13:53"}, // 13 hours 53 minutes (rounded)
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := formatDuration(tt.seconds)
			if result != tt.want {
				t.Errorf("formatDuration(%d) = %s, want %s", tt.seconds, result, tt.want)
			}
		})
	}
}

func TestTimesheetTypstTemplateCompilation(t *testing.T) {
	// Check if Typst is installed
	if err := checkTypstInstalled(); err != nil {
		t.Skip("Typst is not installed, skipping template compilation test")
	}

	// Create temporary directory
	tempDir, err := os.MkdirTemp("", "punchcard-timesheet-test")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer func() { _ = os.RemoveAll(tempDir) }()

	// Create test data file
	testData := `{
		"client_name": "Test Client",
		"project_name": "Test Project",
		"date_range_start": "2025-07-01",
		"date_range_end": "2025-07-31",
		"generated_date": "2025-08-04",
		"contractor_name": "Travis Parker",
		"contractor_label": "Software Development",
		"contractor_email": "travis@example.com",
		"timezone": "UTC",
		"entries": [
			{
				"date": "2025-07-10",
				"start_time": "14:55",
				"end_time": "18:05",
				"duration": "3:10",
				"hours": 3.1667,
				"project_name": "Test Project",
				"description": "Development work"
			},
			{
				"date": "2025-07-10",
				"start_time": "18:42",
				"end_time": "20:04",
				"duration": "1:22",
				"hours": 1.3667,
				"project_name": "Test Project",
				"description": "Code review"
			},
			{
				"date": "2025-07-11",
				"start_time": "13:55",
				"end_time": "18:35",
				"duration": "4:40",
				"hours": 4.6667,
				"project_name": "Test Project",
				"description": "Feature implementation"
			}
		],
		"total_hours": 9.2
	}`

	dataFile := filepath.Join(tempDir, "data.json")
	if err := os.WriteFile(dataFile, []byte(testData), 0o644); err != nil {
		t.Fatalf("Failed to write test data file: %v", err)
	}

	// Write Typst template to temp directory
	typstFile := filepath.Join(tempDir, "timesheet.typ")
	if err := os.WriteFile(typstFile, []byte(templates.TimesheetTemplate), 0o644); err != nil {
		t.Fatalf("Failed to write Typst template: %v", err)
	}

	// Compile with Typst
	outputPDF := filepath.Join(tempDir, "test-timesheet.pdf")
	cmd := exec.Command("typst", "compile", typstFile, outputPDF)
	cmd.Dir = tempDir

	if output, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("Typst compilation failed: %v\nOutput: %s", err, string(output))
	}

	// Verify PDF was created
	if _, err := os.Stat(outputPDF); os.IsNotExist(err) {
		t.Fatalf("PDF file was not created")
	}

	t.Logf("Successfully compiled timesheet Typst template to PDF")
}

func TestGenerateTimesheetPDF(t *testing.T) {
	// Check if Typst is installed
	if err := checkTypstInstalled(); err != nil {
		t.Skip("Typst is not installed, skipping PDF generation test")
	}

	// Create test timesheet data
	timesheetData := &TimesheetData{
		ClientName:  "Test Client Co.",
		ProjectName: "Test Project",
		DateRange: DateRange{
			Start: mustParseTime("2025-07-01T00:00:00Z"),
			End:   mustParseTime("2025-07-31T23:59:59Z"),
		},
		Entries: []TimesheetEntry{
			{
				Date:        "2025-07-10",
				StartTime:   "14:55",
				EndTime:     "18:05",
				Duration:    "3:10",
				Hours:       3.1667,
				ProjectName: "Test Project",
				Description: "Development work",
			},
			{
				Date:        "2025-07-10",
				StartTime:   "18:42",
				EndTime:     "20:04",
				Duration:    "1:22",
				Hours:       1.3667,
				ProjectName: "Test Project",
				Description: "Code review",
			},
			{
				Date:        "2025-07-11",
				StartTime:   "13:55",
				EndTime:     "18:35",
				Duration:    "4:40",
				Hours:       4.6667,
				ProjectName: "Test Project",
				Description: "Feature implementation",
			},
		},
		TotalHours:      9.2,
		GeneratedDate:   mustParseTime("2025-08-04T00:00:00Z"),
		ContractorName:  "Travis Parker",
		ContractorLabel: "Software Development",
		ContractorEmail: "travis@example.com",
		Timezone:        "UTC",
	}

	// Create temporary output file
	tempDir, err := os.MkdirTemp("", "punchcard-timesheet-pdf-test")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer func() { _ = os.RemoveAll(tempDir) }()

	outputPath := filepath.Join(tempDir, "test-timesheet.pdf")

	// Generate PDF
	if err := GenerateTimesheetPDF(timesheetData, outputPath); err != nil {
		t.Fatalf("Failed to generate timesheet PDF: %v", err)
	}

	// Verify PDF was created
	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
		t.Fatalf("PDF file was not created at %s", outputPath)
	}

	t.Logf("Successfully generated timesheet PDF at %s", outputPath)
}

func TestGenerateDefaultTimesheetFilename(t *testing.T) {
	dateRange := DateRange{
		Start: mustParseTime("2025-07-01T00:00:00Z"),
		End:   mustParseTime("2025-07-31T23:59:59Z"),
	}

	tests := []struct {
		name        string
		clientName  string
		projectName string
		want        string
	}{
		{
			name:        "client only",
			clientName:  "Test Client",
			projectName: "",
			want:        "timesheet_Test Client_2025-07_",
		},
		{
			name:        "client and project",
			clientName:  "Test Client",
			projectName: "Test Project",
			want:        "timesheet_Test Client_Test Project_2025-07_",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := GenerateDefaultTimesheetFilename(tt.clientName, tt.projectName, dateRange)

			// Check that the filename starts with the expected pattern
			if len(result) < len(tt.want) || result[:len(tt.want)] != tt.want {
				t.Errorf("GenerateDefaultTimesheetFilename() prefix = %s, want prefix %s", result, tt.want)
			}

			// Check that it ends with .pdf
			if result[len(result)-4:] != ".pdf" {
				t.Errorf("GenerateDefaultTimesheetFilename() should end with .pdf, got %s", result)
			}
		})
	}
}

// Helper functions for tests
func mustParseTime(timeStr string) time.Time {
	t, err := time.Parse(time.RFC3339, timeStr)
	if err != nil {
		panic(err)
	}
	return t
}

func mustLoadLocation(name string) *time.Location {
	loc, err := time.LoadLocation(name)
	if err != nil {
		panic(err)
	}
	return loc
}

func abs(x float64) float64 {
	if x < 0 {
		return -x
	}
	return x
}