package models

import (
	"testing"
	"time"
)

func TestNewLogEntry(t *testing.T) {
	tests := []struct {
		name          string
		filename      string
		line          string
		wantLevel     string
		wantTimestamp bool
	}{
		{
			name:          "Log with ISO8601 timestamp and INFO level",
			filename:      "app.log",
			line:          "2025-11-19T10:00:00 INFO Application started",
			wantLevel:     "INFO",
			wantTimestamp: true,
		},
		{
			name:          "Log with space-separated timestamp and ERROR level",
			filename:      "app.log",
			line:          "2025-11-19 10:00:00 ERROR Connection failed",
			wantLevel:     "ERROR",
			wantTimestamp: true,
		},
		{
			name:          "Log with DEBUG level",
			filename:      "debug.log",
			line:          "DEBUG: Entering function processRequest",
			wantLevel:     "DEBUG",
			wantTimestamp: false,
		},
		{
			name:          "Log with WARN level",
			filename:      "app.log",
			line:          "WARN: Memory usage high",
			wantLevel:     "WARN",
			wantTimestamp: false,
		},
		{
			name:          "Log without level or timestamp",
			filename:      "simple.log",
			line:          "Simple log message",
			wantLevel:     "",
			wantTimestamp: false,
		},
		{
			name:          "Log with FATAL level",
			filename:      "app.log",
			line:          "FATAL: System crash",
			wantLevel:     "FATAL",
			wantTimestamp: false,
		},
		{
			name:          "Log with carriage return",
			filename:      "windows.log",
			line:          "Log line with CR\r\n",
			wantLevel:     "",
			wantTimestamp: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			entry := NewLogEntry(tt.filename, tt.line)

			if entry.Filename != tt.filename {
				t.Errorf("Filename = %v, want %v", entry.Filename, tt.filename)
			}

			if entry.Level != tt.wantLevel {
				t.Errorf("Level = %v, want %v", entry.Level, tt.wantLevel)
			}

			if tt.wantTimestamp && entry.Timestamp.IsZero() {
				t.Error("Expected timestamp to be parsed, but got zero value")
			}

			if !tt.wantTimestamp && !entry.Timestamp.IsZero() {
				t.Error("Expected no timestamp, but got one")
			}

			// Line should have CR/LF trimmed
			if entry.Line != tt.line && entry.Line != tt.line[:len(tt.line)-2] {
				t.Errorf("Line not properly trimmed: %q", entry.Line)
			}
		})
	}
}

func TestLogEntry_TimestampString(t *testing.T) {
	tests := []struct {
		name      string
		timestamp time.Time
		line      string
		want      string
	}{
		{
			name:      "ISO8601 format",
			timestamp: time.Date(2025, 11, 19, 10, 0, 0, 0, time.UTC),
			line:      "2025-11-19T10:00:00 INFO Test",
			want:      "2025-11-19T10:00:00",
		},
		{
			name:      "Space-separated format",
			timestamp: time.Date(2025, 11, 19, 10, 0, 0, 0, time.UTC),
			line:      "2025-11-19 10:00:00 INFO Test",
			want:      "2025-11-19 10:00:00",
		},
		{
			name:      "Zero timestamp",
			timestamp: time.Time{},
			line:      "No timestamp",
			want:      "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			entry := LogEntry{
				Filename:  "test.log",
				Line:      tt.line,
				Timestamp: tt.timestamp,
			}

			got := entry.TimestampString()
			if got != tt.want {
				t.Errorf("TimestampString() = %v, want %v", got, tt.want)
			}
		})
	}
}

func BenchmarkNewLogEntry(b *testing.B) {
	line := "2025-11-19T10:00:00 INFO Application started successfully"
	filename := "app.log"

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = NewLogEntry(filename, line)
	}
}