package iace

import (
	"strings"
	"testing"
)

func TestRenderCrossRefAppendix_EmptyInput(t *testing.T) {
	got := RenderCrossRefAppendix(nil)
	if got != "" {
		t.Errorf("expected empty string for nil input, got %d bytes", len(got))
	}
}

func TestRenderCrossRefAppendix_UnknownIDs(t *testing.T) {
	got := RenderCrossRefAppendix([]string{"ISO-DOES-NOT-EXIST", "EN-ALSO-MISSING"})
	if got != "" {
		t.Errorf("expected empty string when no IDs match, got:\n%s", got)
	}
}

func TestRenderCrossRefAppendix_ISO12100_RendersAllRegions(t *testing.T) {
	got := RenderCrossRefAppendix([]string{"ISO-12100"})
	if got == "" {
		t.Fatal("expected non-empty appendix for ISO-12100")
	}
	for _, want := range []string{
		"## Anhang: Internationale Aequivalenzen",
		"ISO-12100",
		"EU-DIN",
		"US-ANSI",
		"CN-GB",
		"JP-JIS",
		"DIN EN ISO 12100",
		"GB/T 15706",
	} {
		if !strings.Contains(got, want) {
			t.Errorf("expected appendix to contain %q, got:\n%s", want, got)
		}
	}
}

func TestRenderCrossRefAppendix_RegionOrdering(t *testing.T) {
	got := RenderCrossRefAppendix([]string{"EN-60204-1"})
	if got == "" {
		t.Fatal("expected non-empty appendix for EN-60204-1")
	}
	// EU-DIN must appear before US-NFPA which must appear before CN-GB.
	euIdx := strings.Index(got, "EU-DIN")
	usIdx := strings.Index(got, "US-NFPA")
	cnIdx := strings.Index(got, "CN-GB")
	if euIdx < 0 || usIdx < 0 || cnIdx < 0 {
		t.Fatalf("missing one of EU-DIN/US-NFPA/CN-GB markers, got:\n%s", got)
	}
	if !(euIdx < usIdx && usIdx < cnIdx) {
		t.Errorf("expected region order EU-DIN < US-NFPA < CN-GB, got positions %d, %d, %d", euIdx, usIdx, cnIdx)
	}
}

func TestRenderCrossRefAppendix_MultipleNorms_SortedByID(t *testing.T) {
	got := RenderCrossRefAppendix([]string{"ISO-13850", "ISO-12100", "EN-60204-1"})
	if got == "" {
		t.Fatal("expected non-empty appendix")
	}
	// Expect EN-60204-1 first (alphabetical), then ISO-12100, then ISO-13850.
	en := strings.Index(got, "EN-60204-1")
	iso12100 := strings.Index(got, "ISO-12100")
	iso13850 := strings.Index(got, "ISO-13850")
	if en < 0 || iso12100 < 0 || iso13850 < 0 {
		t.Fatalf("missing one of the IDs in output:\n%s", got)
	}
	if !(en < iso12100 && iso12100 < iso13850) {
		t.Errorf("expected source-norm ordering by alphabetical ID, got positions %d, %d, %d", en, iso12100, iso13850)
	}
}

func TestRenderCrossRefAppendix_PipeEscape(t *testing.T) {
	got := RenderCrossRefAppendix([]string{"ISO-12100"})
	// Find a line that came from a mapping with the pipe character — none of
	// our identifiers contain literal '|' so this just checks that the table
	// header is intact (no accidental pipe injection).
	if !strings.Contains(got, "| EU Norm (verwendet) |") {
		t.Errorf("table header malformed:\n%s", got)
	}
}