package runcmd

import (
	"bytes"
	"fmt"
	"os"
	"time"

	"gopkg.in/yaml.v3"

	"github.com/kanootoko/codevault/internal/config"
)

func ConfigExample(configPath string) error {
	configExample := config.Config{
		Environment: config.DevelopmentEnvironment,
		Server: config.ServerConfig{
			Address: ":8080",
			// Example: a Docker-network CIDR in front of a reverse proxy nginx.
			// Replace with the actual proxy's IP/CIDR, or leave empty to trust
			// no forwarded-for headers.
			TrustedProxies: []string{"172.16.0.0/12"},
		},
		Database: config.DatabaseConfig{
			Path: "./codevault.db",
		},
		RateLimit: config.RateLimitConfig{
			MaxFailures: 10,
			Window:      time.Minute,
		},
		Observability: config.ObservabilityConfig{
			Logging: config.LoggingConfig{
				Stderr: config.InfoLoggingLevel,
				Files:  map[config.LoggingLevel]string{config.InfoLoggingLevel: "./info.log"},
				Exporter: config.LogsExporterConfig{
					Level:     config.InfoLoggingLevel,
					Endpoint:  "http://127.0.0.1:4317/v1/logs",
					Transport: "grpc",
				},
			},
			Metrics: config.MetricsConfig{
				Host: "127.0.0.1",
				Port: 9092,
			},
		},
	}
	configBytesBuffer := bytes.NewBuffer(nil)
	encoder := yaml.NewEncoder(configBytesBuffer)
	encoder.SetIndent(2)
	err := encoder.Encode(configExample)
	if err != nil {
		return fmt.Errorf("cannot marshal example config: %w", err)
	}
	err = os.WriteFile(configPath, configBytesBuffer.Bytes(), os.ModePerm)
	if err != nil {
		return fmt.Errorf("cannot write config file: %w", err)
	}
	return nil
}