package main

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

func TestLoadConfig(t *testing.T) {
	t.Run("valid config", func(t *testing.T) {
		dir := t.TempDir()
		writeTestFile(t, dir, "catz.yaml", `catalogs:
  cat1:
    zone: catalog1.example.com.
soa:
  mname: ns1.example.com.
  rname: hostmaster.example.com.
`)
		cfg, err := loadConfig(filepath.Join(dir, "catz.yaml"))
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		if cfg.Catalogs["cat1"].Zone != "catalog1.example.com." {
			t.Errorf("zone = %q, want %q", cfg.Catalogs["cat1"].Zone, "catalog1.example.com.")
		}
	})

	t.Run("normalizes FQDNs", func(t *testing.T) {
		dir := t.TempDir()
		writeTestFile(t, dir, "catz.yaml", `catalogs:
  cat1:
    zone: Catalog1.Example.COM
soa:
  mname: NS1.Example.COM
  rname: Hostmaster.Example.COM
`)
		cfg, err := loadConfig(filepath.Join(dir, "catz.yaml"))
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		if cfg.Catalogs["cat1"].Zone != "catalog1.example.com." {
			t.Errorf("zone = %q, want normalized FQDN", cfg.Catalogs["cat1"].Zone)
		}
		if cfg.SOA.Mname != "ns1.example.com." {
			t.Errorf("mname = %q, want normalized FQDN", cfg.SOA.Mname)
		}
	})

	t.Run("missing file", func(t *testing.T) {
		_, err := loadConfig("/nonexistent/catz.yaml")
		if err == nil {
			t.Fatal("expected error for missing file")
		}
	})

	t.Run("invalid YAML", func(t *testing.T) {
		dir := t.TempDir()
		writeTestFile(t, dir, "catz.yaml", "{{invalid yaml")
		_, err := loadConfig(filepath.Join(dir, "catz.yaml"))
		if err == nil {
			t.Fatal("expected error for invalid YAML")
		}
	})
}

func TestValidateConfig(t *testing.T) {
	t.Run("no catalogs", func(t *testing.T) {
		cfg := &Config{
			Catalogs: map[string]CatalogConfig{},
			SOA:      SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
		}
		if err := validateConfig(cfg); err == nil {
			t.Fatal("expected error for no catalogs")
		}
	})

	t.Run("nil catalogs", func(t *testing.T) {
		cfg := &Config{
			SOA: SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
		}
		if err := validateConfig(cfg); err == nil {
			t.Fatal("expected error for nil catalogs")
		}
	})

	t.Run("empty zone", func(t *testing.T) {
		cfg := &Config{
			Catalogs: map[string]CatalogConfig{"cat1": {Zone: ""}},
			SOA:      SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
		}
		if err := validateConfig(cfg); err == nil {
			t.Fatal("expected error for empty zone")
		}
	})

	t.Run("missing mname", func(t *testing.T) {
		cfg := &Config{
			Catalogs: map[string]CatalogConfig{"cat1": {Zone: "cat.example.com."}},
			SOA:      SOAConfig{Rname: "hostmaster.example.com."},
		}
		if err := validateConfig(cfg); err == nil {
			t.Fatal("expected error for missing mname")
		}
	})

	t.Run("missing rname", func(t *testing.T) {
		cfg := &Config{
			Catalogs: map[string]CatalogConfig{"cat1": {Zone: "cat.example.com."}},
			SOA:      SOAConfig{Mname: "ns1.example.com."},
		}
		if err := validateConfig(cfg); err == nil {
			t.Fatal("expected error for missing rname")
		}
	})

	t.Run("valid config", func(t *testing.T) {
		cfg := &Config{
			Catalogs: map[string]CatalogConfig{"cat1": {Zone: "cat.example.com."}},
			SOA:      SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
		}
		if err := validateConfig(cfg); err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
	})

	t.Run("also-notify references unknown catalog", func(t *testing.T) {
		cfg := &Config{
			Catalogs: map[string]CatalogConfig{"cat1": {Zone: "cat.example.com."}},
			SOA:      SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
			BindConf: BindConfConfig{
				AlsoNotify: map[string][]string{
					"nonexistent": {"198.51.100.1"},
				},
			},
		}
		if err := validateConfig(cfg); err == nil {
			t.Fatal("expected error for also-notify referencing unknown catalog")
		}
	})

	t.Run("also-notify references valid catalog", func(t *testing.T) {
		cfg := &Config{
			Catalogs: map[string]CatalogConfig{"cat1": {Zone: "cat.example.com."}},
			SOA:      SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
			BindConf: BindConfConfig{
				AlsoNotify: map[string][]string{
					"cat1": {"198.51.100.1"},
				},
			},
		}
		if err := validateConfig(cfg); err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
	})
}

func TestLoadConfigWritePermission(t *testing.T) {
	// Test that loadConfig returns error for unreadable file
	dir := t.TempDir()
	path := filepath.Join(dir, "catz.yaml")
	writeTestFile(t, dir, "catz.yaml", "catalogs: {}")
	if err := os.Chmod(path, 0o000); err != nil {
		t.Skip("cannot change file permissions")
	}
	defer os.Chmod(path, 0o644)

	_, err := loadConfig(path)
	if err == nil {
		t.Fatal("expected error for unreadable file")
	}
}