package event

import (
	"errors"
	"fmt"
)

var validTypes = map[string]bool{
	"session.start":     true,
	"session.end":       true,
	"run.start":         true,
	"run.end":           true,
	"span.start":        true,
	"span.end":          true,
	"error":             true,
	"metric.snapshot":   true,
	"openclaw.snapshot": true,
}

type ValidationError struct {
	Field   string
	Message string
}

func (e ValidationError) Error() string {
	return fmt.Sprintf("%s: %s", e.Field, e.Message)
}

func Validate(m map[string]any) error {
	// Check schema
	schema, ok := m["schema"].(map[string]any)
	if !ok {
		return ValidationError{Field: "schema", Message: "missing or invalid"}
	}
	if name, _ := schema["name"].(string); name != "agentmon.event" && name != "agentmon.openclaw" {
		return ValidationError{Field: "schema.name", Message: "must be 'agentmon.event' or 'agentmon.openclaw'"}
	}
	if ver, _ := schema["version"].(float64); ver != 1 {
		return ValidationError{Field: "schema.version", Message: "must be 1"}
	}

	// Check event
	event, ok := m["event"].(map[string]any)
	if !ok {
		return ValidationError{Field: "event", Message: "missing or invalid"}
	}

	if id, _ := event["id"].(string); id == "" {
		return ValidationError{Field: "event.id", Message: "required"}
	}

	eventType, _ := event["type"].(string)
	if eventType == "" {
		return ValidationError{Field: "event.type", Message: "required"}
	}
	if !validTypes[eventType] {
		return ValidationError{Field: "event.type", Message: fmt.Sprintf("invalid type '%s'", eventType)}
	}

	if event["ts"] == nil {
		return ValidationError{Field: "event.ts", Message: "required"}
	}

	// Source is optional for openclaw.snapshot events
	if eventType != "openclaw.snapshot" {
		source, ok := event["source"].(map[string]any)
		if !ok {
			return ValidationError{Field: "event.source", Message: "missing or invalid"}
		}

		if fw, _ := source["framework"].(string); fw == "" {
			return ValidationError{Field: "event.source.framework", Message: "required"}
		}
		if cid, _ := source["client_id"].(string); cid == "" {
			return ValidationError{Field: "event.source.client_id", Message: "required"}
		}
		if host, _ := source["host"].(string); host == "" {
			return ValidationError{Field: "event.source.host", Message: "required"}
		}
	}

	return nil
}

func IsValidationError(err error) bool {
	var ve ValidationError
	return errors.As(err, &ve)
}