package reporter

import (
	"encoding/json"
	"fmt"
	"html/template"
	"os"
	"path/filepath"
	"strings"
	"time"

	"git.gostacks.org/iwasforcedtobehere/stroke/pkg/metrics"
)

// Reporter interface for different output formats
type Reporter interface {
	Generate(results *metrics.Results, outputDir string) error
}

// ConsoleReporter outputs results to the console
type ConsoleReporter struct{}

// NewConsoleReporter creates a new console reporter
func NewConsoleReporter() *ConsoleReporter {
	return &ConsoleReporter{}
}

// Generate outputs results to console
func (cr *ConsoleReporter) Generate(results *metrics.Results, outputDir string) error {
	fmt.Printf("\n📊 Stroke Test Results\n")
	fmt.Print(strings.Repeat("=", 50) + "\n")

	fmt.Printf("Duration: %v\n", results.TestDuration)
	fmt.Printf("Total Requests: %d\n", results.TotalRequests)
	fmt.Printf("Successful: %d\n", results.SuccessRequests)
	fmt.Printf("Failed: %d\n", results.FailedRequests)
	fmt.Printf("RPS: %.2f\n", results.RequestsPerSecond)

	fmt.Printf("\nResponse Times:\n")
	fmt.Printf("  Min: %v\n", results.MinResponseTime)
	fmt.Printf("  Max: %v\n", results.MaxResponseTime)
	fmt.Printf("  Avg: %v\n", results.AvgResponseTime)
	fmt.Printf("  p50: %v\n", results.P50)
	fmt.Printf("  p90: %v\n", results.P90)
	fmt.Printf("  p95: %v\n", results.P95)
	fmt.Printf("  p99: %v\n", results.P99)

	if len(results.StatusCodes) > 0 {
		fmt.Printf("\nStatus Codes:\n")
		for code, count := range results.StatusCodes {
			fmt.Printf("  %d: %d\n", code, count)
		}
	}

	return nil
}

// JSONReporter outputs results as JSON
type JSONReporter struct{}

// NewJSONReporter creates a new JSON reporter
func NewJSONReporter() *JSONReporter {
	return &JSONReporter{}
}

// Generate outputs results as JSON file
func (jr *JSONReporter) Generate(results *metrics.Results, outputDir string) error {
	if err := os.MkdirAll(outputDir, 0755); err != nil {
		return fmt.Errorf("failed to create output directory: %w", err)
	}

	timestamp := time.Now().Format("20060102_150405")
	filename := filepath.Join(outputDir, fmt.Sprintf("stroke_results_%s.json", timestamp))

	file, err := os.Create(filename)
	if err != nil {
		return fmt.Errorf("failed to create JSON file: %w", err)
	}
	defer file.Close()

	encoder := json.NewEncoder(file)
	encoder.SetIndent("", "  ")

	if err := encoder.Encode(results); err != nil {
		return fmt.Errorf("failed to encode JSON: %w", err)
	}

	fmt.Printf("📄 JSON report saved to: %s\n", filename)
	return nil
}

// HTMLReporter generates beautiful HTML reports
type HTMLReporter struct{}

// NewHTMLReporter creates a new HTML reporter
func NewHTMLReporter() *HTMLReporter {
	return &HTMLReporter{}
}

// Generate creates an HTML report
func (hr *HTMLReporter) Generate(results *metrics.Results, outputDir string) error {
	if err := os.MkdirAll(outputDir, 0755); err != nil {
		return fmt.Errorf("failed to create output directory: %w", err)
	}

	timestamp := time.Now().Format("20060102_150405")
	filename := filepath.Join(outputDir, fmt.Sprintf("stroke_report_%s.html", timestamp))

	file, err := os.Create(filename)
	if err != nil {
		return fmt.Errorf("failed to create HTML file: %w", err)
	}
	defer file.Close()

	tmpl := template.Must(template.New("report").Parse(htmlTemplate))

	data := struct {
		Results   *metrics.Results
		Timestamp string
		Title     string
	}{
		Results:   results,
		Timestamp: time.Now().Format("2006-01-02 15:04:05"),
		Title:     "Stroke Stress Test Report",
	}

	if err := tmpl.Execute(file, data); err != nil {
		return fmt.Errorf("failed to execute template: %w", err)
	}

	fmt.Printf("📊 HTML report saved to: %s\n", filename)
	return nil
}

// CSVReporter outputs results as CSV
type CSVReporter struct{}

// NewCSVReporter creates a new CSV reporter
func NewCSVReporter() *CSVReporter {
	return &CSVReporter{}
}

// Generate outputs results as CSV file
func (csvr *CSVReporter) Generate(results *metrics.Results, outputDir string) error {
	if err := os.MkdirAll(outputDir, 0755); err != nil {
		return fmt.Errorf("failed to create output directory: %w", err)
	}

	timestamp := time.Now().Format("20060102_150405")
	filename := filepath.Join(outputDir, fmt.Sprintf("stroke_results_%s.csv", timestamp))

	file, err := os.Create(filename)
	if err != nil {
		return fmt.Errorf("failed to create CSV file: %w", err)
	}
	defer file.Close()

	// Write CSV header
	fmt.Fprintf(file, "Metric,Value\n")
	fmt.Fprintf(file, "Total Requests,%d\n", results.TotalRequests)
	fmt.Fprintf(file, "Success Requests,%d\n", results.SuccessRequests)
	fmt.Fprintf(file, "Failed Requests,%d\n", results.FailedRequests)
	fmt.Fprintf(file, "Test Duration,%v\n", results.TestDuration)
	fmt.Fprintf(file, "Requests Per Second,%.2f\n", results.RequestsPerSecond)
	fmt.Fprintf(file, "Min Response Time,%v\n", results.MinResponseTime)
	fmt.Fprintf(file, "Max Response Time,%v\n", results.MaxResponseTime)
	fmt.Fprintf(file, "Avg Response Time,%v\n", results.AvgResponseTime)
	fmt.Fprintf(file, "P50 Response Time,%v\n", results.P50)
	fmt.Fprintf(file, "P90 Response Time,%v\n", results.P90)
	fmt.Fprintf(file, "P95 Response Time,%v\n", results.P95)
	fmt.Fprintf(file, "P99 Response Time,%v\n", results.P99)

	fmt.Printf("📈 CSV report saved to: %s\n", filename)
	return nil
}

// MultiReporter combines multiple reporters
type MultiReporter struct {
	reporters []Reporter
}

// NewMultiReporter creates a reporter that outputs to multiple formats
func NewMultiReporter(formats []string) *MultiReporter {
	var reporters []Reporter

	for _, format := range formats {
		switch strings.ToLower(format) {
		case "console":
			reporters = append(reporters, NewConsoleReporter())
		case "json":
			reporters = append(reporters, NewJSONReporter())
		case "html":
			reporters = append(reporters, NewHTMLReporter())
		case "csv":
			reporters = append(reporters, NewCSVReporter())
		}
	}

	return &MultiReporter{reporters: reporters}
}

// Generate runs all configured reporters
func (mr *MultiReporter) Generate(results *metrics.Results, outputDir string) error {
	for _, reporter := range mr.reporters {
		if err := reporter.Generate(results, outputDir); err != nil {
			return fmt.Errorf("reporter failed: %w", err)
		}
	}
	return nil
}

// HTML template for the report
const htmlTemplate = `
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>{{.Title}}</title>
    <style>
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            margin: 0;
            padding: 20px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: #333;
        }
        .container {
            max-width: 1200px;
            margin: 0 auto;
            background: white;
            border-radius: 10px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.2);
            overflow: hidden;
        }
        .header {
            background: linear-gradient(135deg, #ff6b6b 0%, #feca57 100%);
            color: white;
            padding: 30px;
            text-align: center;
        }
        .header h1 {
            margin: 0;
            font-size: 2.5em;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
        }
        .content {
            padding: 30px;
        }
        .metrics-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-bottom: 30px;
        }
        .metric-card {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 20px;
            border-left: 4px solid #007bff;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        .metric-title {
            font-size: 0.9em;
            color: #6c757d;
            margin-bottom: 5px;
            text-transform: uppercase;
            letter-spacing: 1px;
        }
        .metric-value {
            font-size: 1.8em;
            font-weight: bold;
            color: #212529;
        }
        .status-codes {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
        }
        .status-codes h3 {
            margin-top: 0;
            color: #495057;
        }
        .status-item {
            display: flex;
            justify-content: space-between;
            padding: 8px 0;
            border-bottom: 1px solid #dee2e6;
        }
        .footer {
            background: #343a40;
            color: white;
            padding: 20px;
            text-align: center;
        }
        .emoji {
            font-size: 1.2em;
        }
        .success { border-left-color: #28a745; }
        .warning { border-left-color: #ffc107; }
        .danger { border-left-color: #dc3545; }
    </style>
</head>
<body>
    <div class="container">
        <div class="header">
            <h1><span class="emoji">🚀</span> {{.Title}} <span class="emoji">🚀</span></h1>
            <p>Generated on {{.Timestamp}}</p>
        </div>
        
        <div class="content">
            <div class="metrics-grid">
                <div class="metric-card success">
                    <div class="metric-title">Total Requests</div>
                    <div class="metric-value">{{.Results.TotalRequests}}</div>
                </div>
                
                <div class="metric-card success">
                    <div class="metric-title">Successful Requests</div>
                    <div class="metric-value">{{.Results.SuccessRequests}}</div>
                </div>
                
                <div class="metric-card {{if gt .Results.FailedRequests 0}}danger{{else}}success{{end}}">
                    <div class="metric-title">Failed Requests</div>
                    <div class="metric-value">{{.Results.FailedRequests}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">Test Duration</div>
                    <div class="metric-value">{{.Results.TestDuration}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">Requests Per Second</div>
                    <div class="metric-value">{{printf "%.2f" .Results.RequestsPerSecond}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">Average Response Time</div>
                    <div class="metric-value">{{.Results.AvgResponseTime}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">P50 Response Time</div>
                    <div class="metric-value">{{.Results.P50}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">P90 Response Time</div>
                    <div class="metric-value">{{.Results.P90}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">P95 Response Time</div>
                    <div class="metric-value">{{.Results.P95}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">P99 Response Time</div>
                    <div class="metric-value">{{.Results.P99}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">Min Response Time</div>
                    <div class="metric-value">{{.Results.MinResponseTime}}</div>
                </div>
                
                <div class="metric-card">
                    <div class="metric-title">Max Response Time</div>
                    <div class="metric-value">{{.Results.MaxResponseTime}}</div>
                </div>
            </div>
            
            {{if .Results.StatusCodes}}
            <div class="status-codes">
                <h3><span class="emoji">📈</span> Status Code Distribution</h3>
                {{range $code, $count := .Results.StatusCodes}}
                <div class="status-item">
                    <span>HTTP {{$code}}</span>
                    <span><strong>{{$count}} requests</strong></span>
                </div>
                {{end}}
            </div>
            {{end}}
        </div>
        
        <div class="footer">
            <p><span class="emoji">💪</span> Powered by Stroke - Because Your Server Needs Some Exercise <span class="emoji">💪</span></p>
            <p>Made with ❤️ and a healthy dose of sarcasm by @iwasforcedtobehere</p>
        </div>
    </div>
</body>
</html>
`