package devtodev

import "encoding/json"

// Payload is the top-level request body for Data API 2.0.
type Payload struct {
	Reports []Report `json:"reports"`
}

// Report groups events for a device (or a player).
type Report struct {
	DeviceID         string            `json:"deviceId"`
	UserID           string            `json:"userId,omitempty"`
	PreviousDeviceID string            `json:"previousDeviceId,omitempty"`
	PreviousUserID   string            `json:"previousUserId,omitempty"`
	DevtodevID       string            `json:"devtodevId,omitempty"`
	Packages         []DevtodevPackage `json:"packages"`
}

// DevtodevPackage groups events under package-level metadata.
type DevtodevPackage struct {
	platform           string
	language           string
	country            string
	ip                 string
	appVersion         string
	appBuildVersion    string
	sdkVersion         string
	bundle             string
	engine             string
	installationSource string
	events             []Event

	reporter *Reporter
}

// Event is the common event interface used by package builders.
type Event interface {
	Payload() map[string]interface{}
	Err() error
}

// RawEvent is a generic event implementation backed by a plain map.
type RawEvent map[string]interface{}

func (e RawEvent) Payload() map[string]interface{} {
	return map[string]interface{}(e)
}

func (e RawEvent) Err() error {
	return nil
}

type builtEvent struct {
	payload map[string]interface{}
	err     error
}

func (e builtEvent) Payload() map[string]interface{} {
	return e.payload
}

func (e builtEvent) Err() error {
	return e.err
}

func (p *DevtodevPackage) WithPlatform(platform string) *DevtodevPackage {
	p.platform = platform
	return p
}

func (p *DevtodevPackage) WithLanguage(language string) *DevtodevPackage {
	p.language = language
	return p
}

func (p *DevtodevPackage) WithCountry(country string) *DevtodevPackage {
	p.country = country
	return p
}

func (p *DevtodevPackage) WithIP(ip string) *DevtodevPackage {
	p.ip = ip
	return p
}

func (p *DevtodevPackage) WithAppVersion(appVersion string) *DevtodevPackage {
	p.appVersion = appVersion
	return p
}

func (p *DevtodevPackage) WithAppBuildVersion(appBuildVersion string) *DevtodevPackage {
	p.appBuildVersion = appBuildVersion
	return p
}

func (p *DevtodevPackage) WithSDKVersion(sdkVersion string) *DevtodevPackage {
	p.sdkVersion = sdkVersion
	return p
}

func (p *DevtodevPackage) WithBundle(bundle string) *DevtodevPackage {
	p.bundle = bundle
	return p
}

func (p *DevtodevPackage) WithEngine(engine string) *DevtodevPackage {
	p.engine = engine
	return p
}

func (p *DevtodevPackage) WithInstallationSource(installationSource string) *DevtodevPackage {
	p.installationSource = installationSource
	return p
}

func (p *DevtodevPackage) Append(events ...Event) *DevtodevPackage {
	if p == nil {
		return nil
	}
	for _, evt := range events {
		if evt == nil {
			continue
		}
		p.events = append(p.events, evt)
	}
	return p
}

func (p *DevtodevPackage) Events() []Event {
	if p == nil {
		return nil
	}
	return p.events
}

func (p DevtodevPackage) MarshalJSON() ([]byte, error) {
	type packageJSON struct {
		Platform           string                   `json:"platform,omitempty"`
		Language           string                   `json:"language,omitempty"`
		Country            string                   `json:"country,omitempty"`
		IP                 string                   `json:"ip,omitempty"`
		AppVersion         string                   `json:"appVersion,omitempty"`
		AppBuildVersion    string                   `json:"appBuildVersion,omitempty"`
		SDKVersion         string                   `json:"sdkVersion,omitempty"`
		Bundle             string                   `json:"bundle,omitempty"`
		Engine             string                   `json:"engine,omitempty"`
		InstallationSource string                   `json:"installationSource,omitempty"`
		Events             []map[string]interface{} `json:"events"`
	}

	events := make([]map[string]interface{}, 0, len(p.events))
	for _, evt := range p.events {
		if evt == nil {
			events = append(events, nil)
			continue
		}
		events = append(events, evt.Payload())
	}

	return json.Marshal(packageJSON{
		Platform:           p.platform,
		Language:           p.language,
		Country:            p.country,
		IP:                 p.ip,
		AppVersion:         p.appVersion,
		AppBuildVersion:    p.appBuildVersion,
		SDKVersion:         p.sdkVersion,
		Bundle:             p.bundle,
		Engine:             p.engine,
		InstallationSource: p.installationSource,
		Events:             events,
	})
}