package config //nolint:testpackage // exercises unexported source constants

import (
	"errors"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"sneak.berlin/go/vaultik/internal/chunker"
)

const (
	testSneakAgePublicKey = "age1278m9q7dp3chsh2dcy82qk27v047zywyvt" +
		"xwnj4cvt0z65jw6a7q5dqhfj"
	testIntegrationAgePublicKey = "age1ezrjmfpwsc95svdg0y54mums3zevgzu" +
		"0x0ecq2f7tp8a05gl0sjq9q9wjg"
	testIntegrationAgePrivateKey = "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GX" +
		"VEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5"
)

func TestMain(m *testing.M) {
	// Set up test environment
	testConfigPath := filepath.Join("..", "..", "test", "config.yaml")

	absPath, err := filepath.Abs(testConfigPath)
	if err == nil {
		_ = os.Setenv("VAULTIK_CONFIG", absPath)
	}

	code := m.Run()
	os.Exit(code)
}

// TestConfigLoad ensures the config package can be imported and basic
// functionality works.
func TestConfigLoad(t *testing.T) {
	t.Parallel()

	// Use the test config file
	configPath := os.Getenv("VAULTIK_CONFIG")
	if configPath == "" {
		t.Fatal("VAULTIK_CONFIG environment variable not set")
	}

	// Test loading the config
	cfg, err := Load(configPath)
	if err != nil {
		t.Fatalf("Failed to load config: %v", err)
	}

	// Basic validation
	if len(cfg.AgeRecipients) != 2 {
		t.Errorf("Expected 2 age recipients, got %d", len(cfg.AgeRecipients))
	}

	if cfg.AgeRecipients[0] != testSneakAgePublicKey {
		t.Errorf("Expected first age recipient to be %s, got '%s'",
			testSneakAgePublicKey, cfg.AgeRecipients[0])
	}

	if len(cfg.Snapshots) != 1 {
		t.Errorf("Expected 1 snapshot, got %d", len(cfg.Snapshots))
	}

	testSnap, ok := cfg.Snapshots["test"]
	if !ok {
		t.Fatal("Expected 'test' snapshot to exist")
	}

	if len(testSnap.Paths) != 2 {
		t.Errorf("Expected 2 paths in test snapshot, got %d", len(testSnap.Paths))
	}

	if testSnap.Paths[0] != "/tmp/vaultik-test-source" {
		t.Errorf("Expected first path to be '/tmp/vaultik-test-source', got '%s'",
			testSnap.Paths[0])
	}

	if cfg.S3.Bucket != "vaultik-test-bucket" {
		t.Errorf("Expected S3 bucket to be 'vaultik-test-bucket', got '%s'",
			cfg.S3.Bucket)
	}

	if cfg.Hostname != "test-host" {
		t.Errorf("Expected hostname to be 'test-host', got '%s'", cfg.Hostname)
	}
}

// TestExampleConfigIsScrubbedAndLoads checks that the shipped
// config.example.yml carries only neutral placeholders (no real credentials,
// private addresses, or internal host names) and still parses.
func TestExampleConfigIsScrubbedAndLoads(t *testing.T) {
	t.Parallel()

	examplePath := filepath.Join("..", "..", "config.example.yml")

	cfg, err := Load(examplePath)
	if err != nil {
		t.Fatalf("Failed to load config.example.yml: %v", err)
	}

	if cfg.StorageURL != "rclone://myremote/path/to/backups" {
		t.Errorf("Expected neutral storage_url, got '%s'", cfg.StorageURL)
	}

	//nolint:gosec // G304: examplePath is a fixed in-repo path, not user input
	raw, err := os.ReadFile(examplePath)
	if err != nil {
		t.Fatalf("Failed to read config.example.yml: %v", err)
	}

	text := string(raw)

	wantSubstrings := []string{
		"YOUR_ACCESS_KEY",
		"YOUR_SECRET_KEY",
		"endpoint: https://",
	}
	for _, want := range wantSubstrings {
		if !strings.Contains(text, want) {
			t.Errorf("Expected config.example.yml to contain %q", want)
		}
	}

	// A raw "http://" scheme would mean a plaintext, likely private endpoint.
	if strings.Contains(text, "http://") {
		t.Error("config.example.yml should not contain an http:// endpoint")
	}
}

// TestConfigFromEnv tests loading config path from environment variable
func TestConfigFromEnv(t *testing.T) {
	t.Parallel()

	configPath := os.Getenv("VAULTIK_CONFIG")
	if configPath == "" {
		t.Skip("VAULTIK_CONFIG not set")
	}

	// Verify the file exists
	//nolint:gosec // G703: test config path comes from the test environment
	_, err := os.Stat(configPath)
	if os.IsNotExist(err) {
		t.Errorf("Config file does not exist at path from VAULTIK_CONFIG: %s",
			configPath)
	}
}

// TestValidateBlobSizeLimit checks the blob_size_limit boundary: it must be at
// least the largest chunk the chunker can emit (chunk_size times
// chunker.ChunkSizeSpread), because the packer places a single such chunk into
// an otherwise empty blob. A limit between chunk_size and that bound is rejected.
func TestValidateBlobSizeLimit(t *testing.T) {
	t.Parallel()

	const chunkSize = Size(10 * 1024 * 1024) // 10MB

	largestChunk := chunkSize.Int64() * chunker.ChunkSizeSpread

	newConfig := func(blobLimit Size) *Config {
		return &Config{
			AgeRecipients:    []string{testSneakAgePublicKey},
			Snapshots:        map[string]SnapshotConfig{"test": {Paths: []string{"/tmp/src"}}},
			StorageURL:       "file:///tmp/vaultik-test-store",
			ChunkSize:        chunkSize,
			BlobSizeLimit:    blobLimit,
			CompressionLevel: 3,
		}
	}

	tests := []struct {
		name      string
		blobLimit Size
		wantErr   bool
	}{
		{
			name:      "at chunk_size but below largest chunk is rejected",
			blobLimit: chunkSize,
			wantErr:   true,
		},
		{
			name:      "between chunk_size and largest chunk is rejected",
			blobLimit: Size(chunkSize.Int64() * 2),
			wantErr:   true,
		},
		{
			name:      "one byte below largest chunk is rejected",
			blobLimit: Size(largestChunk - 1),
			wantErr:   true,
		},
		{
			name:      "exactly at largest chunk is accepted",
			blobLimit: Size(largestChunk),
			wantErr:   false,
		},
		{
			name:      "above largest chunk is accepted",
			blobLimit: Size(largestChunk * 100),
			wantErr:   false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			err := newConfig(tt.blobLimit).Validate()
			if tt.wantErr {
				if !errors.Is(err, errBlobSizeTooSmall) {
					t.Fatalf("Validate() error = %v, want errBlobSizeTooSmall", err)
				}

				return
			}

			if err != nil {
				t.Fatalf("Validate() unexpected error: %v", err)
			}
		})
	}
}

// TestValidateAgeRecipients checks that recipients are parsed at config load
// (a bad entry fails immediately, not mid-backup) and that no invalid entry —
// least of all a pasted secret key — is echoed in the error.
func TestValidateAgeRecipients(t *testing.T) {
	t.Parallel()

	baseConfig := func(recipients []string) *Config {
		return &Config{
			AgeRecipients:    recipients,
			Snapshots:        map[string]SnapshotConfig{"test": {Paths: []string{"/tmp/src"}}},
			StorageURL:       "file:///tmp/vaultik-test-store",
			ChunkSize:        Size(10 * 1024 * 1024),
			BlobSizeLimit:    Size(10 * 1024 * 1024 * 1024),
			CompressionLevel: 3,
		}
	}

	tests := []struct {
		name       string
		recipients []string
		wantErr    bool
	}{
		{
			name:       "config init placeholder is rejected",
			recipients: []string{"age1REPLACE_WITH_YOUR_PUBLIC_KEY"},
			wantErr:    true,
		},
		{
			name:       "ssh-ed25519 recipient is rejected",
			recipients: []string{"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIexamplekeydata"},
			wantErr:    true,
		},
		{
			name:       "truncated age1 string is rejected",
			recipients: []string{"age1short"},
			wantErr:    true,
		},
		{
			name:       "secret key passed as recipient is rejected",
			recipients: []string{testIntegrationAgePrivateKey},
			wantErr:    true,
		},
		{
			name:       "two valid recipients are accepted",
			recipients: []string{testSneakAgePublicKey, testIntegrationAgePublicKey},
			wantErr:    false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			err := baseConfig(tt.recipients).Validate()
			if !tt.wantErr {
				if err != nil {
					t.Fatalf("Validate() unexpected error: %v", err)
				}

				return
			}

			if err == nil {
				t.Fatal("Validate() returned nil, want error")
			}

			// The entry itself must never appear in the error, since a
			// recipient string can be a secret key.
			for _, recipient := range tt.recipients {
				if strings.Contains(err.Error(), recipient) {
					t.Fatalf("Validate() error echoed the recipient value: %v", err)
				}
			}
		})
	}
}

// TestAgeSecretKeySourceName checks the name reported for the configured
// age secret key: the recorded source when Load set one, and the
// config-file field name for a Config built directly (as in tests).
func TestAgeSecretKeySourceName(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name   string
		source string
		want   string
	}{
		{
			name:   "unset defaults to config field",
			source: "",
			want:   ageSecretKeySourceConfig,
		},
		{
			name:   "environment source",
			source: ageSecretKeySourceEnv,
			want:   ageSecretKeySourceEnv,
		},
		{
			name:   "config-file source",
			source: ageSecretKeySourceConfig,
			want:   ageSecretKeySourceConfig,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			cfg := &Config{AgeSecretKeySource: tt.source}
			if got := cfg.AgeSecretKeySourceName(); got != tt.want {
				t.Errorf("AgeSecretKeySourceName() = %q, want %q", got, tt.want)
			}
		})
	}
}