package config

import "encoding/json"

const redactedSecret = "[REDACTED]"

// Redacted returns a detached configuration view suitable for diagnostics.
func (c *Config) Redacted() Config {
	if c == nil {
		return Config{}
	}
	redacted := cloneConfig(*c)
	redactAuth(&redacted.Gateway.Auth)
	redactAuth(&redacted.Distribution.Auth)
	redactAuth(&redacted.Admin.Auth)
	for name, upstream := range redacted.Upstreams {
		redactProviderAuth(&upstream.API.Auth)
		upstream.ProxyAuth.Password = redact(upstream.ProxyAuth.Password)
		redacted.Upstreams[name] = upstream
	}
	redacted.Storage.PostgresURL = redact(redacted.Storage.PostgresURL)
	redacted.Storage.RedisURL = redact(redacted.Storage.RedisURL)
	return redacted
}

func (c *Config) String() string {
	if c == nil {
		return "<nil>"
	}
	encoded, err := json.Marshal(c.Redacted())
	if err != nil {
		return `{"config":"[REDACTED]"}`
	}
	return string(encoded)
}

func (c *Config) GoString() string { return c.String() }

func redactAuth(auth *Auth) {
	auth.Password = redact(auth.Password)
	auth.Token = redact(auth.Token)
	for index := range auth.Methods {
		auth.Methods[index].Password = redact(auth.Methods[index].Password)
		auth.Methods[index].Value = redact(auth.Methods[index].Value)
	}
}

func redactProviderAuth(auth *ProviderAuth) {
	auth.Password = redact(auth.Password)
	auth.Token = redact(auth.Token)
	auth.Value = redact(auth.Value)
}

func redact(value string) string {
	if value == "" {
		return ""
	}
	return redactedSecret
}

func cloneConfig(source Config) Config {
	cloned := source
	cloned.Defaults.Check.URLs = cloneStrings(source.Defaults.Check.URLs)
	cloned.Gateway = cloneListener(source.Gateway)
	cloned.Distribution.Listener = cloneListener(source.Distribution.Listener)
	cloned.Admin = cloneListener(source.Admin)
	cloned.Routing = make([]Routing, len(source.Routing))
	for index, route := range source.Routing {
		cloned.Routing[index] = cloneRouting(route)
	}
	cloned.Upstreams = make(map[string]Upstream, len(source.Upstreams))
	for name, upstream := range source.Upstreams {
		cloned.Upstreams[name] = cloneUpstream(upstream)
	}
	return cloned
}

func cloneListener(source Listener) Listener {
	cloned := source
	cloned.Access.AllowCIDRs = cloneStrings(source.Access.AllowCIDRs)
	cloned.Access.TrustedProxies = cloneStrings(source.Access.TrustedProxies)
	cloned.Auth.CIDRs = cloneStrings(source.Auth.CIDRs)
	cloned.Auth.Methods = append([]AuthMethod(nil), source.Auth.Methods...)
	for index := range cloned.Auth.Methods {
		cloned.Auth.Methods[index].CIDRs = cloneStrings(source.Auth.Methods[index].CIDRs)
	}
	cloned.Retry.RetryMethods = cloneStrings(source.Retry.RetryMethods)
	cloned.DestinationPolicy.DenyCIDRs = cloneStrings(source.DestinationPolicy.DenyCIDRs)
	return cloned
}

func cloneRouting(source Routing) Routing {
	cloned := source
	cloned.Match.Methods = cloneStrings(source.Match.Methods)
	cloned.Match.Headers = cloneStringMap(source.Match.Headers)
	cloned.Upstreams = cloneStrings(source.Upstreams)
	cloned.Strategy.Weights = cloneIntMap(source.Strategy.Weights)
	return cloned
}

func cloneUpstream(source Upstream) Upstream {
	cloned := source
	cloned.Exposure = cloneStrings(source.Exposure)
	cloned.Provider.Protocols = cloneStrings(source.Provider.Protocols)
	cloned.API.Headers = cloneStringMap(source.API.Headers)
	cloned.API.Query = cloneStringMap(source.API.Query)
	cloned.API.Body.Value = cloneStringMap(source.API.Body.Value)
	cloned.Check.URLs = cloneStrings(source.Check.URLs)
	return cloned
}

func cloneStrings(source []string) []string {
	return append([]string(nil), source...)
}

func cloneStringMap(source map[string]string) map[string]string {
	if source == nil {
		return nil
	}
	cloned := make(map[string]string, len(source))
	for key, value := range source {
		cloned[key] = value
	}
	return cloned
}

func cloneIntMap(source map[string]int) map[string]int {
	if source == nil {
		return nil
	}
	cloned := make(map[string]int, len(source))
	for key, value := range source {
		cloned[key] = value
	}
	return cloned
}