package main

import (
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

func TestIntegrationEndToEnd(t *testing.T) {
	dir := t.TempDir()

	// Write config
	configContent := `catalogs:
  catalog1:
    zone: catalog1.example.com.
  catalog2:
    zone: catalog2.example.com.

soa:
  mname: ns1.example.com.
  rname: hostmaster.example.com.
`
	writeTestFile(t, dir, "catz.yaml", configContent)

	// Write input
	inputContent := `# Test zones
zone.example.org    catalog1, catalog2
zone.example.com    catalog2, coo=old-catalog.example.com.
test.example.net    catalog1, group=internal
app.example.org     catalog1, group=external, coo=migrated.example.com.
`
	writeTestFile(t, dir, "zones.txt", inputContent)

	cfg, err := loadConfig(filepath.Join(dir, "catz.yaml"))
	if err != nil {
		t.Fatalf("loadConfig: %v", err)
	}

	members, err := parseInput(filepath.Join(dir, "zones.txt"), cfg)
	if err != nil {
		t.Fatalf("parseInput: %v", err)
	}

	now := fixedTime(2026, 1, 15)

	// First run: should create files
	for catName, catMembers := range members {
		changed, err := processCatalog(catName, cfg, catMembers, dir, now)
		if err != nil {
			t.Fatalf("processCatalog(%s): %v", catName, err)
		}
		if !changed {
			t.Errorf("expected %s to be changed on first run", catName)
		}
	}

	// Verify files exist
	cat1Path := filepath.Join(dir, "catalog1.example.com.zone")
	cat2Path := filepath.Join(dir, "catalog2.example.com.zone")

	cat1Content := readTestFile(t, cat1Path)
	cat2Content := readTestFile(t, cat2Path)

	// Verify catalog1 content
	assertContains(t, cat1Content, "catalog1.example.com.\t0\tIN\tSOA")
	assertContains(t, cat1Content, "catalog1.example.com.\t0\tIN\tNS\tinvalid.")
	assertContains(t, cat1Content, "version.catalog1.example.com.\t0\tIN\tTXT\t\"2\"")
	assertContains(t, cat1Content, "IN\tPTR\tapp.example.org.")
	assertContains(t, cat1Content, "IN\tPTR\ttest.example.net.")
	assertContains(t, cat1Content, "IN\tPTR\tzone.example.org.")
	assertContains(t, cat1Content, "IN\tTXT\t\"internal\"")
	assertContains(t, cat1Content, "IN\tTXT\t\"external\"")
	assertContains(t, cat1Content, "IN\tPTR\tmigrated.example.com.")

	// Verify catalog2 content
	assertContains(t, cat2Content, "catalog2.example.com.\t0\tIN\tSOA")
	assertContains(t, cat2Content, "IN\tPTR\tzone.example.com.")
	assertContains(t, cat2Content, "IN\tPTR\tzone.example.org.")
	assertContains(t, cat2Content, "IN\tPTR\told-catalog.example.com.")

	// Verify serial format
	assertContains(t, cat1Content, "2026011501")

	// Second run (same time): should be unchanged
	for catName, catMembers := range members {
		changed, err := processCatalog(catName, cfg, catMembers, dir, now)
		if err != nil {
			t.Fatalf("processCatalog(%s) second run: %v", catName, err)
		}
		if changed {
			t.Errorf("expected %s to be unchanged on second run", catName)
		}
	}

	// Verify content hasn't changed
	cat1After := readTestFile(t, cat1Path)
	if cat1After != cat1Content {
		t.Error("catalog1 content changed on idempotent run")
	}
}

func TestIntegrationSerialBump(t *testing.T) {
	dir := t.TempDir()

	configContent := `catalogs:
  cat1:
    zone: cat1.example.com.

soa:
  mname: ns1.example.com.
  rname: hostmaster.example.com.
`
	writeTestFile(t, dir, "catz.yaml", configContent)

	cfg, err := loadConfig(filepath.Join(dir, "catz.yaml"))
	if err != nil {
		t.Fatal(err)
	}

	members1 := []ZoneEntry{
		{Zone: "a.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 1},
	}

	now := fixedTime(2026, 1, 15)

	// First run
	changed, err := processCatalog("cat1", cfg, members1, dir, now)
	if err != nil {
		t.Fatal(err)
	}
	if !changed {
		t.Error("expected changed on first run")
	}

	content1 := readTestFile(t, filepath.Join(dir, "cat1.example.com.zone"))
	assertContains(t, content1, "2026011501")

	// Second run with different input (same day)
	members2 := []ZoneEntry{
		{Zone: "a.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 1},
		{Zone: "b.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 2},
	}

	changed, err = processCatalog("cat1", cfg, members2, dir, now)
	if err != nil {
		t.Fatal(err)
	}
	if !changed {
		t.Error("expected changed when input differs")
	}

	content2 := readTestFile(t, filepath.Join(dir, "cat1.example.com.zone"))
	assertContains(t, content2, "2026011502")

	// Third run with same input: unchanged
	changed, err = processCatalog("cat1", cfg, members2, dir, now)
	if err != nil {
		t.Fatal(err)
	}
	if changed {
		t.Error("expected unchanged on third run")
	}

	// Fourth run next day with same input: new serial
	nextDay := fixedTime(2026, 1, 16)
	changed, err = processCatalog("cat1", cfg, members2, dir, nextDay)
	if err != nil {
		t.Fatal(err)
	}
	// Content hasn't changed, so this should be unchanged even though date differs
	if changed {
		t.Error("expected unchanged when content hasn't changed")
	}
}

func TestIntegrationSortOrder(t *testing.T) {
	dir := t.TempDir()

	configContent := `catalogs:
  cat1:
    zone: cat1.example.com.

soa:
  mname: ns1.example.com.
  rname: hostmaster.example.com.
`
	writeTestFile(t, dir, "catz.yaml", configContent)

	cfg, err := loadConfig(filepath.Join(dir, "catz.yaml"))
	if err != nil {
		t.Fatal(err)
	}

	// Input in reverse order
	members := []ZoneEntry{
		{Zone: "z.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 1},
		{Zone: "m.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 2},
		{Zone: "a.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 3},
	}

	now := fixedTime(2026, 1, 15)
	_, err = processCatalog("cat1", cfg, members, dir, now)
	if err != nil {
		t.Fatal(err)
	}

	content := readTestFile(t, filepath.Join(dir, "cat1.example.com.zone"))
	lines := splitLines(content)

	// Find PTR lines and verify order
	var ptrZones []string
	for _, line := range lines {
		if strings.Contains(line, "\tPTR\t") && !strings.Contains(line, "coo.") {
			// Extract the PTR target
			parts := strings.Split(line, "\t")
			ptrZones = append(ptrZones, parts[len(parts)-1])
		}
	}

	if len(ptrZones) != 3 {
		t.Fatalf("expected 3 PTR records, got %d", len(ptrZones))
	}
	if ptrZones[0] != "a.example.com." || ptrZones[1] != "m.example.com." || ptrZones[2] != "z.example.com." {
		t.Errorf("PTR records not sorted: %v", ptrZones)
	}
}

func TestIntegrationCLI(t *testing.T) {
	// Build the binary
	binary := filepath.Join(t.TempDir(), "catalog-zone-gen")
	cmd := exec.Command("go", "build", "-o", binary, ".")
	cmd.Dir = projectDir(t)
	if out, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("go build failed: %v\n%s", err, out)
	}

	dir := t.TempDir()

	configContent := `catalogs:
  catalog1:
    zone: catalog1.example.com.

soa:
  mname: ns1.example.com.
  rname: hostmaster.example.com.
`
	writeTestFile(t, dir, "catz.yaml", configContent)

	inputContent := "a.example.com.    catalog1\n"
	writeTestFile(t, dir, "zones.txt", inputContent)

	// Run the binary
	cmd = exec.Command(binary, "--config", filepath.Join(dir, "catz.yaml"), "--output-dir", dir, filepath.Join(dir, "zones.txt"))
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("catalog-zone-gen failed: %v\n%s", err, out)
	}

	// Verify output file exists
	zonePath := filepath.Join(dir, "catalog1.example.com.zone")
	if _, err := os.Stat(zonePath); err != nil {
		t.Fatalf("output file not created: %v", err)
	}

	content := readTestFile(t, zonePath)
	assertContains(t, content, "catalog1.example.com.")
	assertContains(t, content, "a.example.com.")
}

func TestIntegrationCLIErrors(t *testing.T) {
	binary := filepath.Join(t.TempDir(), "catalog-zone-gen")
	cmd := exec.Command("go", "build", "-o", binary, ".")
	cmd.Dir = projectDir(t)
	if out, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("go build failed: %v\n%s", err, out)
	}

	t.Run("no arguments", func(t *testing.T) {
		cmd := exec.Command(binary)
		err := cmd.Run()
		if err == nil {
			t.Error("expected error with no arguments")
		}
	})

	t.Run("missing input file", func(t *testing.T) {
		cmd := exec.Command(binary, "/nonexistent/zones.txt")
		err := cmd.Run()
		if err == nil {
			t.Error("expected error with missing input file")
		}
	})

	t.Run("unknown catalog in input", func(t *testing.T) {
		dir := t.TempDir()
		writeTestFile(t, dir, "catz.yaml", `catalogs:
  cat1:
    zone: cat1.example.com.
soa:
  mname: ns1.example.com.
  rname: hostmaster.example.com.
`)
		writeTestFile(t, dir, "zones.txt", "a.example.com.    unknown_catalog\n")

		cmd := exec.Command(binary,
			"--config", filepath.Join(dir, "catz.yaml"),
			"--output-dir", dir,
			filepath.Join(dir, "zones.txt"))
		out, err := cmd.CombinedOutput()
		if err == nil {
			t.Error("expected error for unknown catalog")
		}
		assertContains(t, string(out), "unknown catalog")
	})
}

func writeTestFile(t *testing.T, dir, name, content string) {
	t.Helper()
	if err := os.WriteFile(filepath.Join(dir, name), []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
}

func readTestFile(t *testing.T, path string) string {
	t.Helper()
	data, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	return string(data)
}

func projectDir(t *testing.T) string {
	t.Helper()
	// Find the project root by looking for go.mod
	dir, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	for {
		if _, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil {
			return dir
		}
		parent := filepath.Dir(dir)
		if parent == dir {
			t.Fatal("could not find project root (go.mod)")
		}
		dir = parent
	}
}

// Verify the serial stays the same when the same time is used but content changes on a new day.
func TestIntegrationSerialNewDay(t *testing.T) {
	dir := t.TempDir()

	configContent := `catalogs:
  cat1:
    zone: cat1.example.com.

soa:
  mname: ns1.example.com.
  rname: hostmaster.example.com.
`
	writeTestFile(t, dir, "catz.yaml", configContent)

	cfg, err := loadConfig(filepath.Join(dir, "catz.yaml"))
	if err != nil {
		t.Fatal(err)
	}

	members := []ZoneEntry{
		{Zone: "a.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 1},
	}

	day1 := fixedTime(2026, 1, 15)
	_, err = processCatalog("cat1", cfg, members, dir, day1)
	if err != nil {
		t.Fatal(err)
	}

	content1 := readTestFile(t, filepath.Join(dir, "cat1.example.com.zone"))
	assertContains(t, content1, "2026011501")

	// Add a zone on day 2
	members2 := []ZoneEntry{
		{Zone: "a.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 1},
		{Zone: "b.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 2},
	}

	day2 := fixedTime(2026, 1, 16)
	changed, err := processCatalog("cat1", cfg, members2, dir, day2)
	if err != nil {
		t.Fatal(err)
	}
	if !changed {
		t.Error("expected changed with new zone")
	}

	content2 := readTestFile(t, filepath.Join(dir, "cat1.example.com.zone"))
	assertContains(t, content2, "2026011601")

	// Simulate not using the tool for a while, running on a much later date
	day3 := fixedTime(2026, 6, 15)
	members3 := []ZoneEntry{
		{Zone: "a.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 1},
		{Zone: "b.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 2},
		{Zone: "c.example.com.", Catalogs: []string{"cat1"}, File: "test", Line: 3},
	}

	changed, err = processCatalog("cat1", cfg, members3, dir, day3)
	if err != nil {
		t.Fatal(err)
	}
	if !changed {
		t.Error("expected changed with new zone")
	}

	content3 := readTestFile(t, filepath.Join(dir, "cat1.example.com.zone"))
	assertContains(t, content3, "2026061501")
}