package mq

import (
	"context"
	"encoding/json"
	"fmt"
	"runtime"
	"time"
)

type Result struct {
	Payload     json.RawMessage `json:"payload"`
	Topic       string          `json:"topic"`
	CreatedAt   time.Time       `json:"created_at"`
	ProcessedAt time.Time       `json:"processed_at,omitempty"`
	TaskID      string          `json:"task_id"`
	Error       error           `json:"error,omitempty"`
	Status      string          `json:"status"`
}

func (r Result) Unmarshal(data any) error {
	if r.Payload == nil {
		return fmt.Errorf("payload is nil")
	}
	return json.Unmarshal(r.Payload, data)
}

func HandleError(ctx context.Context, err error, status ...string) Result {
	st := "Failed"
	if len(status) > 0 {
		st = status[0]
	}
	if err == nil {
		return Result{}
	}
	return Result{
		Status: st,
		Error:  err,
	}
}

func (r Result) WithData(status string, data []byte) Result {
	if r.Error != nil {
		return r
	}
	return Result{
		Status:  status,
		Payload: data,
		Error:   nil,
	}
}

type TLSConfig struct {
	UseTLS   bool
	CertPath string
	KeyPath  string
	CAPath   string
}

type Options struct {
	syncMode            bool
	brokerAddr          string
	callback            []func(context.Context, Result) Result
	maxRetries          int
	consumerOnSubscribe func(ctx context.Context, topic, consumerName string)
	consumerOnClose     func(ctx context.Context, topic, consumerName string)
	notifyResponse      func(context.Context, Result)
	initialDelay        time.Duration
	maxBackoff          time.Duration
	jitterPercent       float64
	tlsConfig           TLSConfig
	aesKey              json.RawMessage
	hmacKey             json.RawMessage
	enableEncryption    bool
	queueSize           int
	numOfWorkers        int
	maxMemoryLoad       int64
	enableWorkerPool    bool
}

func defaultOptions() Options {
	return Options{
		brokerAddr:    ":8080",
		maxRetries:    5,
		initialDelay:  2 * time.Second,
		maxBackoff:    20 * time.Second,
		jitterPercent: 0.5,
		queueSize:     100,
		hmacKey:       []byte(`a9f4b9415485b70275673b5920182796ea497b5e093ead844a43ea5d77cbc24f`),
		numOfWorkers:  runtime.NumCPU(),
		maxMemoryLoad: 5000000,
	}
}

// Option defines a function type for setting options.
type Option func(*Options)

func setupOptions(opts ...Option) Options {
	options := defaultOptions()
	for _, opt := range opts {
		opt(&options)
	}
	return options
}

func WithNotifyResponse(handler func(ctx context.Context, result Result)) Option {
	return func(opts *Options) {
		opts.notifyResponse = handler
	}
}

func WithWorkerPool(queueSize, numOfWorkers int, maxMemoryLoad int64) Option {
	return func(opts *Options) {
		opts.enableWorkerPool = true
		opts.queueSize = queueSize
		opts.numOfWorkers = numOfWorkers
		opts.maxMemoryLoad = maxMemoryLoad
	}
}

func WithConsumerOnSubscribe(handler func(ctx context.Context, topic, consumerName string)) Option {
	return func(opts *Options) {
		opts.consumerOnSubscribe = handler
	}
}

func WithConsumerOnClose(handler func(ctx context.Context, topic, consumerName string)) Option {
	return func(opts *Options) {
		opts.consumerOnClose = handler
	}
}

func WithSecretKey(aesKey json.RawMessage) Option {
	return func(opts *Options) {
		opts.aesKey = aesKey
		opts.enableEncryption = true
	}
}

func WithHMACKey(hmacKey json.RawMessage) Option {
	return func(opts *Options) {
		opts.hmacKey = hmacKey
	}
}

// WithBrokerURL -
func WithBrokerURL(url string) Option {
	return func(opts *Options) {
		opts.brokerAddr = url
	}
}

// WithTLS - Option to enable/disable TLS
func WithTLS(enableTLS bool, certPath, keyPath string) Option {
	return func(o *Options) {
		o.tlsConfig.UseTLS = enableTLS
		o.tlsConfig.CertPath = certPath
		o.tlsConfig.KeyPath = keyPath
	}
}

// WithCAPath - Option to enable/disable TLS
func WithCAPath(caPath string) Option {
	return func(o *Options) {
		o.tlsConfig.CAPath = caPath
	}
}

// WithSyncMode -
func WithSyncMode(mode bool) Option {
	return func(opts *Options) {
		opts.syncMode = mode
	}
}

// WithMaxRetries -
func WithMaxRetries(val int) Option {
	return func(opts *Options) {
		opts.maxRetries = val
	}
}

// WithInitialDelay -
func WithInitialDelay(val time.Duration) Option {
	return func(opts *Options) {
		opts.initialDelay = val
	}
}

// WithMaxBackoff -
func WithMaxBackoff(val time.Duration) Option {
	return func(opts *Options) {
		opts.maxBackoff = val
	}
}

// WithCallback -
func WithCallback(val ...func(context.Context, Result) Result) Option {
	return func(opts *Options) {
		opts.callback = val
	}
}

// WithJitterPercent -
func WithJitterPercent(val float64) Option {
	return func(opts *Options) {
		opts.jitterPercent = val
	}
}