package messaging

import (
	"fmt"
	"log"
	"strings"
	"time"
)

type Message struct {
	FrenName string
	Message  string
}

func (m *Message) Encode() string {
	return m.FrenName + " " + m.Message
}

func Decode(message string) (*Message, error) {
	content := strings.SplitN(message, " ", 2)
	if len(content) < 2 {
		return nil, fmt.Errorf("no space delimiter")
	}
	return &Message{
		FrenName: content[0],
		Message:  content[1],
	}, nil
}

func IdContinuation(message Message) ContinuationChain {
	return func(success Continuation, _failure Continuation) ContinuationChain {
		return success(message)
	}
}

func FailurePassingContinuation(message Message) ContinuationChain {
	return func(_success Continuation, failure Continuation) ContinuationChain {
		return failure(message)
	}
}

func LogContinuation(message Message) ContinuationChain {
	return func(success Continuation, _failure Continuation) ContinuationChain {
		now := time.Now().UTC()

		log.Println(now, message)
		return success(message)
	}
}

// basically b(a(message)) if and only if b is successful
func Compose(a Continuation, b Continuation) Continuation {
	return func(message Message) ContinuationChain {
		return func(success Continuation, failure Continuation) ContinuationChain {
			return b(message)(a, FailurePassingContinuation)(success, failure)
		}
	}
}

type Continuation func(Message) ContinuationChain
type ContinuationChain func(Continuation, Continuation) ContinuationChain