package logger

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

func TestInit(t *testing.T) {
	// Create temp directory
	tmpDir := t.TempDir()
	oldHome := os.Getenv("HOME")
	os.Setenv("HOME", tmpDir)
	defer os.Setenv("HOME", oldHome)

	tests := []struct {
		name     string
		logLevel string
	}{
		{"default level", "info"},
		{"debug level", "debug"},
		{"warn level", "warn"},
		{"error level", "error"},
		{"invalid level defaults to info", "invalid"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			err := Init(tt.logLevel)
			if err != nil {
				t.Errorf("Init(%q) unexpected error: %v", tt.logLevel, err)
			}

			// Check log file was created
			logFile := filepath.Join(tmpDir, ".config", "grokkit", "grokkit.log")
			if _, err := os.Stat(logFile); os.IsNotExist(err) {
				t.Errorf("Log file not created at %s", logFile)
			}
		})
	}
}

func TestLogging(t *testing.T) {
	tmpDir := t.TempDir()
	oldHome := os.Getenv("HOME")
	os.Setenv("HOME", tmpDir)
	defer os.Setenv("HOME", oldHome)

	if err := Init("debug"); err != nil {
		t.Fatalf("Init() failed: %v", err)
	}

	// Test all log levels with structured fields
	Debug("test debug message", "key", "value")
	Info("test info message", "count", 42)
	Warn("test warn message", "enabled", true)
	Error("test error message", "error", "something went wrong")

	// Verify log file has content
	logFile := filepath.Join(tmpDir, ".config", "grokkit", "grokkit.log")
	content, err := os.ReadFile(logFile)
	if err != nil {
		t.Errorf("Failed to read log file: %v", err)
	}
	if len(content) == 0 {
		t.Errorf("Log file is empty")
	}

	// Check for JSON structure (slog uses JSON handler)
	contentStr := string(content)
	if !strings.Contains(contentStr, `"level"`) {
		t.Errorf("Log content doesn't contain JSON level field")
	}
	if !strings.Contains(contentStr, `"msg"`) {
		t.Errorf("Log content doesn't contain JSON msg field")
	}
}

func TestSetLevel(t *testing.T) {
	tmpDir := t.TempDir()
	oldHome := os.Getenv("HOME")
	os.Setenv("HOME", tmpDir)
	defer os.Setenv("HOME", oldHome)

	if err := Init("info"); err != nil {
		t.Fatalf("Init() failed: %v", err)
	}

	// Change level to debug
	SetLevel("debug")

	// Log at debug level
	Debug("debug after level change", "test", true)

	// Verify log file has the debug message
	logFile := filepath.Join(tmpDir, ".config", "grokkit", "grokkit.log")
	content, err := os.ReadFile(logFile)
	if err != nil {
		t.Errorf("Failed to read log file: %v", err)
	}

	if !strings.Contains(string(content), "debug after level change") {
		t.Errorf("Debug message not found after level change")
	}
}

func TestWith(t *testing.T) {
	tmpDir := t.TempDir()
	oldHome := os.Getenv("HOME")
	os.Setenv("HOME", tmpDir)
	defer os.Setenv("HOME", oldHome)

	if err := Init("info"); err != nil {
		t.Fatalf("Init() failed: %v", err)
	}

	// Create logger with context
	contextLogger := With("request_id", "123", "user", "testuser")
	if contextLogger == nil {
		t.Errorf("With() returned nil logger")
	}
}