package config

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

func TestLoad_ValidConfig(t *testing.T) {
	content := `
inputs:
  unix_sockets:
    - name: http
      path: /var/run/logcorrelator/http.socket
      format: json
    - name: network
      path: /var/run/logcorrelator/network.socket
      format: json

outputs:
  file:
    path: /var/log/logcorrelator/correlated.log
  clickhouse:
    dsn: clickhouse://user:pass@localhost:9000/db
    table: correlated_logs

correlation:
  time_window_s: 1
  emit_orphans: true
`

	tmpDir := t.TempDir()
	configPath := filepath.Join(tmpDir, "config.yml")
	if err := os.WriteFile(configPath, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

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

	if len(cfg.Inputs.UnixSockets) != 2 {
		t.Errorf("expected 2 unix sockets, got %d", len(cfg.Inputs.UnixSockets))
	}
	if cfg.Outputs.File.Path != "/var/log/logcorrelator/correlated.log" {
		t.Errorf("expected file path /var/log/logcorrelator/correlated.log, got %s", cfg.Outputs.File.Path)
	}
}

func TestLoad_InvalidPath(t *testing.T) {
	_, err := Load("/nonexistent/path/config.yml")
	if err == nil {
		t.Error("expected error for nonexistent path")
	}
}

func TestLoad_InvalidYAML(t *testing.T) {
	tmpDir := t.TempDir()
	configPath := filepath.Join(tmpDir, "config.yml")
	content := `invalid: yaml: content: [`
	if err := os.WriteFile(configPath, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	_, err := Load(configPath)
	if err == nil {
		t.Error("expected error for invalid YAML")
	}
}

func TestLoad_DefaultValues(t *testing.T) {
	tmpDir := t.TempDir()
	configPath := filepath.Join(tmpDir, "config.yml")
	content := `
inputs:
  unix_sockets:
    - name: a
      path: /tmp/a.sock
    - name: b
      path: /tmp/b.sock
outputs:
  file:
    path: /var/log/test.log
`
	if err := os.WriteFile(configPath, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

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

	// Check defaults
	if cfg.Correlation.TimeWindowS != 1 {
		t.Errorf("expected default time window value 1, got %d", cfg.Correlation.TimeWindowS)
	}
	if cfg.Correlation.EmitOrphans != true {
		t.Error("expected default emit_orphans to be true")
	}
}

func TestValidate_MinimumInputs(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "only_one", Path: "/tmp/test.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: "/var/log/test.log"},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for less than 2 inputs")
	}
}

func TestValidate_AtLeastOneOutput(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File:       FileOutputConfig{},
			ClickHouse: ClickHouseOutputConfig{Enabled: false},
			Stdout:     StdoutOutputConfig{Enabled: false},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for no outputs enabled")
	}
}

func TestGetTimeWindow(t *testing.T) {
	tests := []struct {
		name     string
		config   CorrelationConfig
		expected time.Duration
	}{
		{
			name: "1 second",
			config: CorrelationConfig{
				TimeWindowS: 1,
			},
			expected: time.Second,
		},
		{
			name: "5 seconds",
			config: CorrelationConfig{
				TimeWindowS: 5,
			},
			expected: 5 * time.Second,
		},
		{
			name: "default",
			config: CorrelationConfig{
				TimeWindowS: 0,
			},
			expected: time.Second,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := tt.config.GetTimeWindow()
			if result != tt.expected {
				t.Errorf("expected %v, got %v", tt.expected, result)
			}
		})
	}
}

func TestValidate_DuplicateNames(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "same", Path: "/tmp/a.sock"},
				{Name: "same", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: "/var/log/test.log"},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for duplicate names")
	}
}

func TestValidate_DuplicatePaths(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/same.sock"},
				{Name: "b", Path: "/tmp/same.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: "/var/log/test.log"},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for duplicate paths")
	}
}

func TestValidate_EmptyName(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: "/var/log/test.log"},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for empty name")
	}
}

func TestValidate_EmptyPath(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: ""},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: "/var/log/test.log"},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for empty path")
	}
}

func TestValidate_EmptyFilePath(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: ""},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for empty file path")
	}
}

func TestValidate_ClickHouseMissingDSN(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: ""},
			ClickHouse: ClickHouseOutputConfig{
				Enabled: true,
				DSN:     "",
				Table:   "test",
			},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for missing ClickHouse DSN")
	}
}

func TestValidate_ClickHouseMissingTable(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: ""},
			ClickHouse: ClickHouseOutputConfig{
				Enabled: true,
				DSN:     "clickhouse://localhost:9000/db",
				Table:   "",
			},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for missing ClickHouse table")
	}
}

func TestValidate_ClickHouseInvalidBatchSize(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: ""},
			ClickHouse: ClickHouseOutputConfig{
				Enabled:   true,
				DSN:       "clickhouse://localhost:9000/db",
				Table:     "test",
				BatchSize: 0,
			},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for invalid batch size")
	}
}

func TestValidate_ClickHouseInvalidMaxBufferSize(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: ""},
			ClickHouse: ClickHouseOutputConfig{
				Enabled:       true,
				DSN:           "clickhouse://localhost:9000/db",
				Table:         "test",
				BatchSize:     100,
				MaxBufferSize: 0,
			},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for invalid max buffer size")
	}
}

func TestValidate_ClickHouseInvalidTimeout(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: ""},
			ClickHouse: ClickHouseOutputConfig{
				Enabled:   true,
				DSN:       "clickhouse://localhost:9000/db",
				Table:     "test",
				BatchSize: 100,
				TimeoutMs: 0,
			},
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for invalid timeout")
	}
}

func TestValidate_EmptyCorrelationKey(t *testing.T) {
	cfg := &Config{
		Inputs: InputsConfig{
			UnixSockets: []UnixSocketConfig{
				{Name: "a", Path: "/tmp/a.sock"},
				{Name: "b", Path: "/tmp/b.sock"},
			},
		},
		Outputs: OutputsConfig{
			File: FileOutputConfig{Path: "/var/log/test.log"},
		},
		Correlation: CorrelationConfig{
			TimeWindowS: 0,
		},
	}

	err := cfg.Validate()
	if err == nil {
		t.Error("expected error for invalid time window")
	}
}

func TestGetSocketPermissions(t *testing.T) {
	tests := []struct {
		name     string
		config   UnixSocketConfig
		expected os.FileMode
	}{
		{
			name: "default",
			config: UnixSocketConfig{
				SocketPermissions: "",
			},
			expected: 0660,
		},
		{
			name: "explicit 0660",
			config: UnixSocketConfig{
				SocketPermissions: "0660",
			},
			expected: 0660,
		},
		{
			name: "explicit 0666",
			config: UnixSocketConfig{
				SocketPermissions: "0666",
			},
			expected: 0666,
		},
		{
			name: "without leading zero",
			config: UnixSocketConfig{
				SocketPermissions: "660",
			},
			expected: 0660,
		},
		{
			name: "invalid value",
			config: UnixSocketConfig{
				SocketPermissions: "invalid",
			},
			expected: 0660,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := tt.config.GetSocketPermissions()
			if result != tt.expected {
				t.Errorf("expected %o, got %o", tt.expected, result)
			}
		})
	}
}

func TestLogConfig_GetLevel(t *testing.T) {
	tests := []struct {
		name     string
		config   LogConfig
		expected string
	}{
		{
			name:     "default",
			config:   LogConfig{Level: ""},
			expected: "INFO",
		},
		{
			name:     "DEBUG uppercase",
			config:   LogConfig{Level: "DEBUG"},
			expected: "DEBUG",
		},
		{
			name:     "debug lowercase",
			config:   LogConfig{Level: "debug"},
			expected: "DEBUG",
		},
		{
			name:     "WARN",
			config:   LogConfig{Level: "WARN"},
			expected: "WARN",
		},
		{
			name:     "ERROR",
			config:   LogConfig{Level: "ERROR"},
			expected: "ERROR",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := tt.config.GetLevel()
			if result != tt.expected {
				t.Errorf("GetLevel() = %v, want %v", result, tt.expected)
			}
		})
	}
}

func TestLoad_LogLevel(t *testing.T) {
	content := `
log:
  level: DEBUG

inputs:
  unix_sockets:
    - name: http
      path: /var/run/logcorrelator/http.socket
    - name: network
      path: /var/run/logcorrelator/network.socket

outputs:
  file:
    path: /var/log/test.log

correlation:
  time_window_s: 1
  emit_orphans: true
`

	tmpDir := t.TempDir()
	configPath := filepath.Join(tmpDir, "config.yml")
	if err := os.WriteFile(configPath, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

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

	if cfg.Log.GetLevel() != "DEBUG" {
		t.Errorf("expected log level DEBUG, got %s", cfg.Log.GetLevel())
	}
}

func TestLoad_StdoutEnabledObject(t *testing.T) {
	content := `
inputs:
  unix_sockets:
    - name: http
      path: /var/run/logcorrelator/http.socket
    - name: network
      path: /var/run/logcorrelator/network.socket

outputs:
  stdout:
    enabled: true

correlation:
  time_window_s: 1
  emit_orphans: true
`

	tmpDir := t.TempDir()
	configPath := filepath.Join(tmpDir, "config.yml")
	if err := os.WriteFile(configPath, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

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

	if !cfg.Outputs.Stdout.Enabled {
		t.Error("expected outputs.stdout.enabled to be true")
	}
}