package devtodev

import "fmt"

// ValidatePayload checks for required fields and common schema errors.
func ValidatePayload(payload Payload) error {
	if len(payload.Reports) == 0 {
		return fmt.Errorf("reports is required")
	}
	for ri, report := range payload.Reports {
		if report.DeviceID == "" {
			return fmt.Errorf("reports[%d].deviceId is required", ri)
		}
		if len(report.Packages) == 0 {
			return fmt.Errorf("reports[%d].packages is required", ri)
		}
		for pi, pkg := range report.Packages {
			if len(pkg.Events) == 0 {
				return fmt.Errorf("reports[%d].packages[%d].events is required", ri, pi)
			}
			for ei, event := range pkg.Events {
				code, ok := event["code"]
				if !ok {
					return fmt.Errorf("reports[%d].packages[%d].events[%d].code is required", ri, pi, ei)
				}
				if codeStr, ok := code.(string); !ok || codeStr == "" {
					return fmt.Errorf("reports[%d].packages[%d].events[%d].code must be a non-empty string", ri, pi, ei)
				}
				ts, ok := event["timestamp"]
				if !ok {
					return fmt.Errorf("reports[%d].packages[%d].events[%d].timestamp is required", ri, pi, ei)
				}
				if !isNumber(ts) {
					return fmt.Errorf("reports[%d].packages[%d].events[%d].timestamp must be a number", ri, pi, ei)
				}
			}
		}
	}
	return nil
}

func isNumber(v interface{}) bool {
	switch v.(type) {
	case int, int8, int16, int32, int64:
		return true
	case uint, uint8, uint16, uint32, uint64:
		return true
	case float32, float64:
		return true
	default:
		return false
	}
}