package logger

import (
	"bytes"
	"strings"
	"testing"
)

func TestNewTextLogger(t *testing.T) {
	var buf bytes.Buffer
	l := New(&buf, LevelDebug, "text")

	l.Info("hello world", "key", "value")

	output := buf.String()
	if !strings.Contains(output, "hello world") {
		t.Errorf("expected output to contain 'hello world', got: %s", output)
	}
	if !strings.Contains(output, "key") {
		t.Errorf("expected output to contain 'key', got: %s", output)
	}
	if !strings.Contains(output, "value") {
		t.Errorf("expected output to contain 'value', got: %s", output)
	}
}

func TestNewJSONLogger(t *testing.T) {
	var buf bytes.Buffer
	l := New(&buf, LevelDebug, "json")

	l.Info("hello world", "key", "value")

	output := buf.String()
	if !strings.Contains(output, `"msg":"hello world"`) {
		t.Errorf("expected JSON output to contain msg, got: %s", output)
	}
}

func TestLogLevels(t *testing.T) {
	var buf bytes.Buffer
	l := New(&buf, LevelWarn, "text")

	l.Debug("debug msg")
	l.Info("info msg")
	l.Warn("warn msg")
	l.Error("error msg")

	output := buf.String()
	if strings.Contains(output, "debug") {
		t.Error("debug message should be filtered out at WARN level")
	}
	if strings.Contains(output, "info") {
		t.Error("info message should be filtered out at WARN level")
	}
	if !strings.Contains(output, "warn") {
		t.Error("warn message should appear")
	}
	if !strings.Contains(output, "error") {
		t.Error("error message should appear")
	}
}

func TestWithFields(t *testing.T) {
	var buf bytes.Buffer
	l := New(&buf, LevelDebug, "text")

	child := l.With("request_id", "abc123", "user_id", "user-1")
	child.Info("request processed")

	output := buf.String()
	if !strings.Contains(output, "request_id") || !strings.Contains(output, "abc123") {
		t.Errorf("expected 'request_id=abc123' in output, got: %s", output)
	}
	if !strings.Contains(output, "user_id") || !strings.Contains(output, "user-1") {
		t.Errorf("expected 'user_id=user-1' in output, got: %s", output)
	}
}

func TestNewNop(t *testing.T) {
	l := NewNop()
	var buf bytes.Buffer
	// Nop logger should not write anything
	l2 := New(&buf, LevelDebug, "text")
	l2.Info("should appear")
	if !strings.Contains(buf.String(), "should appear") {
		t.Error("normal logger should write")
	}
	// Nop logger itself is fine to call
	l.Info("should not appear")
	l.Error("should not appear")
}

func TestParseLevel(t *testing.T) {
	tests := []struct {
		input    string
		expected Level
		hasError bool
	}{
		{"debug", LevelDebug, false},
		{"DEBUG", LevelDebug, false},
		{"info", LevelInfo, false},
		{"warn", LevelWarn, false},
		{"error", LevelError, false},
		{"ERROR", LevelError, false},
		{"invalid", LevelInfo, true},
		{"", LevelInfo, true},
	}

	for _, tt := range tests {
		t.Run(tt.input, func(t *testing.T) {
			level, err := ParseLevel(tt.input)
			if tt.hasError && err == nil {
				t.Errorf("ParseLevel(%q) expected error but got none", tt.input)
			}
			if !tt.hasError && err != nil {
				t.Errorf("ParseLevel(%q) unexpected error: %v", tt.input, err)
			}
			if level != tt.expected {
				t.Errorf("ParseLevel(%q) = %v, want %v", tt.input, level, tt.expected)
			}
		})
	}
}

func TestRedaction(t *testing.T) {
	var buf bytes.Buffer
	l := New(&buf, LevelDebug, "text")

	l.Info("auth attempt", "api_key", "sk-abcdefgh12345678", "user_id", "user-1")

	output := buf.String()
	if strings.Contains(output, "sk-abcdefgh12345678") {
		t.Errorf("API key should be redacted, got: %s", output)
	}
	if !strings.Contains(output, "sk-") && !strings.Contains(output, "****") {
		t.Errorf("expected redacted value with mask, got: %s", output)
	}
	if !strings.Contains(output, "user-1") {
		t.Errorf("non-sensitive field should NOT be redacted, got: %s", output)
	}
}

func TestRedactSensitiveKeys(t *testing.T) {
	sensitiveTests := []string{"api_key", "API_KEY", "password", "secret", "token", "jwt_secret", "admin_password", "llm_api_key", "dashscope_api_key", "access_token"}
	nonSensitiveTests := []string{"user_id", "request_id", "model", "port", "host", "query", "duration_ms", "count"}

	for _, key := range sensitiveTests {
		val := redactValue(key, "super-secret-value-12345")
		if s, ok := val.(string); ok {
			if s == "super-secret-value-12345" {
				t.Errorf("key %q should be redacted, got raw value instead", key)
			}
			if !strings.Contains(s, "****") {
				t.Errorf("key %q redacted value should contain '****', got: %s", key, s)
			}
		}
	}

	for _, key := range nonSensitiveTests {
		val := redactValue(key, "normal-value")
		if s, ok := val.(string); ok {
			if s != "normal-value" {
				t.Errorf("key %q should NOT be redacted, got: %s", key, s)
			}
		}
	}
}

func TestRedactShortValue(t *testing.T) {
	// Short values (< 4 chars) should be fully masked
	val := redactValue("api_key", "ab")
	if s, ok := val.(string); ok {
		if s != "****" {
			t.Errorf("short value should be fully masked, got: %s", s)
		}
	}
}

func TestOddNumberOfArgs(t *testing.T) {
	// Go's slog vet check prevents odd numbers of arguments at compile time.
	// Our wrapper detects this and appends a !MISSING placeholder internally.
	// This test verifies buildAttrs handles odd args correctly.
	var buf bytes.Buffer
	l := New(&buf, LevelDebug, "text")
	attrs := l.buildAttrs("key1", "value1", "key2")
	if len(attrs) != 2 {
		t.Errorf("expected 2 attrs, got %d", len(attrs))
	}
	if attrs[1].Key != "key2" {
		t.Errorf("expected attrs[1].Key=key2, got %s", attrs[1].Key)
	}
	// The value for key2 should be "!MISSING"
	if attrs[1].Value.String() != "!MISSING" {
		t.Errorf("expected !MISSING placeholder, got %s", attrs[1].Value.String())
	}
}