package iace

import (
	"bytes"
	"encoding/json"
	"strings"
	"testing"

	"github.com/google/uuid"
)

// createTestExportData builds a complete set of test data for document export tests.
func createTestExportData() (*Project, []TechFileSection, []Hazard, []RiskAssessment, []Mitigation, []RegulatoryClassification) {
	projectID := uuid.New()
	hazardID1 := uuid.New()
	hazardID2 := uuid.New()

	project := &Project{
		ID:              projectID,
		MachineName:     "Robot Arm XY-200",
		MachineType:     "industrial_robot",
		Manufacturer:    "TestCorp GmbH",
		Description:     "6-Achsen Industrieroboter fuer Schweissarbeiten",
		CEMarkingTarget: "2023/1230",
	}

	sections := []TechFileSection{
		{ID: uuid.New(), ProjectID: projectID, SectionType: "risk_assessment_report", Title: "Risikobeurteilung", Content: "Dies ist der Risikobeurteilungsbericht...", Status: TechFileSectionStatusApproved},
		{ID: uuid.New(), ProjectID: projectID, SectionType: "hazard_log_combined", Title: "Gefaehrdungsprotokoll", Content: "Protokoll aller identifizierten Gefaehrdungen...", Status: TechFileSectionStatusGenerated},
		{ID: uuid.New(), ProjectID: projectID, SectionType: "declaration_of_conformity", Title: "EU-Konformitaetserklaerung", Content: "Hiermit erklaeren wir...", Status: TechFileSectionStatusDraft},
	}

	hazards := []Hazard{
		{ID: hazardID1, ProjectID: projectID, Name: "Quetschgefahr", Category: "mechanical", Description: "Quetschgefahr durch Roboterarm"},
		{ID: hazardID2, ProjectID: projectID, Name: "Elektrischer Schlag", Category: "electrical", Description: "Gefahr durch freiliegende Kontakte"},
	}

	assessments := []RiskAssessment{
		{ID: uuid.New(), HazardID: hazardID1, Severity: 4, Exposure: 3, Probability: 3, InherentRisk: 36, CEff: 0.7, ResidualRisk: 10.8, RiskLevel: RiskLevelHigh, IsAcceptable: false},
		{ID: uuid.New(), HazardID: hazardID2, Severity: 2, Exposure: 2, Probability: 2, InherentRisk: 8, CEff: 0.8, ResidualRisk: 1.6, RiskLevel: RiskLevelLow, IsAcceptable: true},
	}

	mitigations := []Mitigation{
		{ID: uuid.New(), HazardID: hazardID1, ReductionType: ReductionTypeDesign, Name: "Schutzabdeckung", Status: MitigationStatusVerified},
		{ID: uuid.New(), HazardID: hazardID1, ReductionType: ReductionTypeProtective, Name: "Lichtschranke", Status: MitigationStatusVerified},
		{ID: uuid.New(), HazardID: hazardID2, ReductionType: ReductionTypeInformation, Name: "Warnhinweis", Status: MitigationStatusPlanned},
	}

	classifications := []RegulatoryClassification{
		{Regulation: RegulationMachineryRegulation, ClassificationResult: "Annex I", RiskLevel: RiskLevelHigh},
		{Regulation: RegulationCRA, ClassificationResult: "Important", RiskLevel: RiskLevelMedium},
	}

	return project, sections, hazards, assessments, mitigations, classifications
}

// createEmptyExportData builds minimal test data with no hazards, sections, or mitigations.
func createEmptyExportData() (*Project, []TechFileSection, []Hazard, []RiskAssessment, []Mitigation, []RegulatoryClassification) {
	project := &Project{
		ID:              uuid.New(),
		MachineName:     "Empty Machine",
		MachineType:     "test",
		Manufacturer:    "TestCorp",
		Description:     "",
		CEMarkingTarget: "",
	}
	return project, nil, nil, nil, nil, nil
}

// ============================================================================
// PDF Export Tests
// ============================================================================

func TestExportPDF_ValidOutput(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, hazards, assessments, mitigations, classifications := createTestExportData()

	data, err := exporter.ExportPDF(project, sections, hazards, assessments, mitigations, classifications)
	if err != nil {
		t.Fatalf("ExportPDF returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportPDF returned empty bytes")
	}

	// Valid PDF files start with %PDF-
	if !bytes.HasPrefix(data, []byte("%PDF-")) {
		t.Errorf("ExportPDF output does not start with %%PDF-, got first 10 bytes: %q", data[:min(10, len(data))])
	}
}

func TestExportPDF_EmptyProject(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, hazards, assessments, mitigations, classifications := createEmptyExportData()

	data, err := exporter.ExportPDF(project, sections, hazards, assessments, mitigations, classifications)
	if err != nil {
		t.Fatalf("ExportPDF with empty project returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportPDF with empty project returned empty bytes")
	}

	// Should still produce a valid PDF even with no content
	if !bytes.HasPrefix(data, []byte("%PDF-")) {
		t.Errorf("ExportPDF output does not start with %%PDF-, got first 10 bytes: %q", data[:min(10, len(data))])
	}
}

// ============================================================================
// Excel Export Tests
// ============================================================================

func TestExportExcel_ValidOutput(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, hazards, assessments, mitigations, _ := createTestExportData()

	data, err := exporter.ExportExcel(project, sections, hazards, assessments, mitigations)
	if err != nil {
		t.Fatalf("ExportExcel returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportExcel returned empty bytes")
	}

	// xlsx is a zip archive, which starts with PK (0x50, 0x4b)
	if !bytes.HasPrefix(data, []byte("PK")) {
		t.Errorf("ExportExcel output does not start with PK (zip signature), got first 4 bytes: %x", data[:min(4, len(data))])
	}
}

func TestExportExcel_EmptyProject(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, hazards, assessments, mitigations, _ := createEmptyExportData()

	data, err := exporter.ExportExcel(project, sections, hazards, assessments, mitigations)
	if err != nil {
		t.Fatalf("ExportExcel with empty project returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportExcel with empty project returned empty bytes")
	}

	// Should still produce a valid xlsx (zip) even with no data
	if !bytes.HasPrefix(data, []byte("PK")) {
		t.Errorf("ExportExcel output does not start with PK (zip signature), got first 4 bytes: %x", data[:min(4, len(data))])
	}
}

// ============================================================================
// Markdown Export Tests
// ============================================================================

func TestExportMarkdown_ContainsSections(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, _, _, _, _ := createTestExportData()

	data, err := exporter.ExportMarkdown(project, sections)
	if err != nil {
		t.Fatalf("ExportMarkdown returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportMarkdown returned empty bytes")
	}

	content := string(data)

	// Should contain the project name
	if !strings.Contains(content, project.MachineName) {
		t.Errorf("ExportMarkdown output does not contain project name %q", project.MachineName)
	}

	// Should contain each section title
	for _, section := range sections {
		if !strings.Contains(content, section.Title) {
			t.Errorf("ExportMarkdown output does not contain section title %q", section.Title)
		}
	}

	// Should contain markdown header syntax
	if !strings.Contains(content, "#") {
		t.Error("ExportMarkdown output does not contain any markdown headers")
	}
}

func TestExportMarkdown_EmptyProject(t *testing.T) {
	exporter := NewDocumentExporter()
	project, _, _, _, _, _ := createEmptyExportData()

	data, err := exporter.ExportMarkdown(project, nil)
	if err != nil {
		t.Fatalf("ExportMarkdown with empty project returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportMarkdown with empty project returned empty bytes")
	}

	content := string(data)

	// Should still contain the project name as a header even without sections
	if !strings.Contains(content, project.MachineName) {
		t.Errorf("ExportMarkdown output does not contain project name %q for empty project", project.MachineName)
	}
}

// ============================================================================
// DOCX Export Tests
// ============================================================================

func TestExportDOCX_ValidOutput(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, _, _, _, _ := createTestExportData()

	data, err := exporter.ExportDOCX(project, sections)
	if err != nil {
		t.Fatalf("ExportDOCX returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportDOCX returned empty bytes")
	}

	// docx is a zip archive, which starts with PK (0x50, 0x4b)
	if !bytes.HasPrefix(data, []byte("PK")) {
		t.Errorf("ExportDOCX output does not start with PK (zip signature), got first 4 bytes: %x", data[:min(4, len(data))])
	}
}

func TestExportDOCX_EmptyProject(t *testing.T) {
	exporter := NewDocumentExporter()
	project, _, _, _, _, _ := createEmptyExportData()

	data, err := exporter.ExportDOCX(project, nil)
	if err != nil {
		t.Fatalf("ExportDOCX with empty project returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportDOCX with empty project returned empty bytes")
	}

	// Should still produce a valid docx (zip) even with no sections
	if !bytes.HasPrefix(data, []byte("PK")) {
		t.Errorf("ExportDOCX output does not start with PK (zip signature), got first 4 bytes: %x", data[:min(4, len(data))])
	}
}

// ============================================================================
// Helper Function Tests
// ============================================================================

// ============================================================================
// JSON Export Tests
// ============================================================================

func TestExportJSON_ValidOutput(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, hazards, assessments, mitigations, classifications := createTestExportData()

	data, err := exporter.ExportJSON(project, sections, hazards, assessments, mitigations, classifications)
	if err != nil {
		t.Fatalf("ExportJSON returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportJSON returned empty bytes")
	}

	// Must be valid JSON
	var parsed map[string]interface{}
	if err := json.Unmarshal(data, &parsed); err != nil {
		t.Fatalf("ExportJSON output is not valid JSON: %v", err)
	}

	// Check required top-level keys
	requiredKeys := []string{"project", "sections", "hazards", "assessments", "mitigations", "classifications", "exported_at", "format_version"}
	for _, key := range requiredKeys {
		if _, ok := parsed[key]; !ok {
			t.Errorf("ExportJSON output missing key %q", key)
		}
	}

	// format_version should be "1.0"
	if fv, _ := parsed["format_version"].(string); fv != "1.0" {
		t.Errorf("Expected format_version '1.0', got %q", fv)
	}
}

func TestExportJSON_EmptyProject(t *testing.T) {
	exporter := NewDocumentExporter()
	project, sections, hazards, assessments, mitigations, classifications := createEmptyExportData()

	data, err := exporter.ExportJSON(project, sections, hazards, assessments, mitigations, classifications)
	if err != nil {
		t.Fatalf("ExportJSON with empty project returned error: %v", err)
	}

	var parsed map[string]interface{}
	if err := json.Unmarshal(data, &parsed); err != nil {
		t.Fatalf("ExportJSON output is not valid JSON: %v", err)
	}

	// Project should still be present
	if parsed["project"] == nil {
		t.Error("ExportJSON should include project even for empty project")
	}
}

func TestExportJSON_NilProject_ReturnsError(t *testing.T) {
	exporter := NewDocumentExporter()

	_, err := exporter.ExportJSON(nil, nil, nil, nil, nil, nil)
	if err == nil {
		t.Error("ExportJSON should return error for nil project")
	}
}

// ============================================================================
// Special Character Tests
// ============================================================================

func TestExportMarkdown_GermanUmlauts(t *testing.T) {
	exporter := NewDocumentExporter()
	project := &Project{
		ID:           uuid.New(),
		MachineName:  "Pruefgeraet fuer Sicherheitsueberwachung",
		MachineType:  "Pruefstand",
		Manufacturer: "Mueller & Soehne GmbH",
	}
	sections := []TechFileSection{
		{SectionType: "general_description", Title: "Allgemeine Beschreibung", Content: "Aenderungen und Ergaenzungen"},
	}

	data, err := exporter.ExportMarkdown(project, sections)
	if err != nil {
		t.Fatalf("ExportMarkdown with German text returned error: %v", err)
	}

	content := string(data)
	if !strings.Contains(content, "Pruefgeraet") {
		t.Error("Markdown should preserve German text")
	}
	if !strings.Contains(content, "Mueller") {
		t.Error("Markdown should preserve manufacturer name with special chars")
	}
}

func TestExportDOCX_SpecialCharacters(t *testing.T) {
	exporter := NewDocumentExporter()
	project := &Project{
		ID:           uuid.New(),
		MachineName:  "Test <Machine> & \"Quotes\"",
		MachineType:  "test",
		Manufacturer: "Corp <&>",
	}
	sections := []TechFileSection{
		{SectionType: "general_description", Title: "Title with <angle> & \"quotes\"", Content: "Content with <special> & chars"},
	}

	data, err := exporter.ExportDOCX(project, sections)
	if err != nil {
		t.Fatalf("ExportDOCX with special characters returned error: %v", err)
	}

	if len(data) == 0 {
		t.Fatal("ExportDOCX with special characters returned empty bytes")
	}

	// Should still produce a valid zip
	if !bytes.HasPrefix(data, []byte("PK")) {
		t.Error("ExportDOCX output should still be valid zip even with special characters")
	}
}

func TestExportPDF_GermanText(t *testing.T) {
	exporter := NewDocumentExporter()
	project := &Project{
		ID:           uuid.New(),
		MachineName:  "Sicherheits-Pruefstand SP-400",
		Manufacturer: "Deutsche Prueftechnik AG",
	}
	sections := []TechFileSection{
		{SectionType: "general_description", Title: "Beschreibung", Content: "Technische Dokumentation fuer den Sicherheits-Pruefstand"},
	}

	data, err := exporter.ExportPDF(project, sections, nil, nil, nil, nil)
	if err != nil {
		t.Fatalf("ExportPDF with German text returned error: %v", err)
	}

	if !bytes.HasPrefix(data, []byte("%PDF-")) {
		t.Error("ExportPDF should produce valid PDF with German text")
	}
}

// ============================================================================
// Helper Function Tests
// ============================================================================

func TestRiskLevelLabel_AllLevels(t *testing.T) {
	levels := []RiskLevel{
		RiskLevelCritical,
		RiskLevelHigh,
		RiskLevelMedium,
		RiskLevelLow,
		RiskLevelNegligible,
		RiskLevelNotAcceptable,
		RiskLevelVeryHigh,
	}

	for _, level := range levels {
		t.Run(string(level), func(t *testing.T) {
			label := riskLevelLabel(level)
			if label == "" {
				t.Errorf("riskLevelLabel(%q) returned empty string", level)
			}
		})
	}
}

func TestRiskLevelColor_AllLevels(t *testing.T) {
	levels := []RiskLevel{
		RiskLevelCritical,
		RiskLevelHigh,
		RiskLevelMedium,
		RiskLevelLow,
		RiskLevelNegligible,
		RiskLevelNotAcceptable,
		RiskLevelVeryHigh,
	}

	for _, level := range levels {
		t.Run(string(level), func(t *testing.T) {
			r, g, b := riskLevelColor(level)
			// RGB values must be in valid range 0-255
			if r < 0 || r > 255 {
				t.Errorf("riskLevelColor(%q) red value %d out of range [0,255]", level, r)
			}
			if g < 0 || g > 255 {
				t.Errorf("riskLevelColor(%q) green value %d out of range [0,255]", level, g)
			}
			if b < 0 || b > 255 {
				t.Errorf("riskLevelColor(%q) blue value %d out of range [0,255]", level, b)
			}
		})
	}
}