package assign

import (
	"encoding/json"
	"fmt"
	"time"

	occ "git.novox.be/novox/mesh-contracts/operator-and-conversation/go/clients/operatorchannelclient"
	oc "git.novox.be/novox/mesh-contracts/operator-and-conversation/go/seats/operatorchannel"
	"git.novox.be/novox/mesh-sdk/go/delivery"
)

// assignerAsk is the asking-th ask a, as the asks state holds it: the router's ask as JSON (delivery.AssignerAsk.Ask).
func assignerAsk(asking int, a oc.Ask) delivery.AssignerAsk {
	raw, err := json.Marshal(a)
	if err != nil { // an oc.Ask holds only strings, bools and a slice of them: it cannot fail
		panic(fmt.Sprintf("assign: the ask %q does not marshal: %v", a.ID, err))
	}
	return delivery.AssignerAsk{Asking: asking, Ask: raw}
}

// AskOf is the router's ask an asks-state value carries.
func AskOf(a delivery.AssignerAsk) (oc.Ask, error) {
	var ask oc.Ask
	if err := json.Unmarshal(a.Ask, &ask); err != nil {
		return oc.Ask{}, fmt.Errorf("assign: the value carries no router's ask: %w", err)
	}
	return ask, nil
}

// EncodeAsk is delivery.EncodeAssignerAsk at key, after the checks every keeper of an ask owes (occ.Carried, ADR 0627 §4):
// the ask's id is delivery.AskingID(key, asking), and it offers at least one option.
func EncodeAsk(key string, a delivery.AssignerAsk) ([]byte, error) {
	if _, err := checkedAsk(key, a); err != nil {
		return nil, err
	}
	return delivery.EncodeAssignerAsk(key, a)
}

func checkedAsk(key string, a delivery.AssignerAsk) (oc.Ask, error) {
	ask, err := occ.Carried(a.Ask, delivery.AskingID(key, a.Asking))
	if err != nil {
		return oc.Ask{}, fmt.Errorf("assign: %w", err)
	}
	return ask, nil
}

// DecodeAsk reads the ask at key (delivery.DecodeAssignerAsk) with the router's ask it carries.
func DecodeAsk(key string, data []byte) (delivery.AssignerAsk, oc.Ask, error) {
	a, err := delivery.DecodeAssignerAsk(key, data)
	if err != nil {
		return delivery.AssignerAsk{}, oc.Ask{}, err
	}
	ask, err := checkedAsk(key, a)
	if err != nil {
		return delivery.AssignerAsk{}, oc.Ask{}, err
	}
	return a, ask, nil
}

// ExpiresAt is when the ask ends unanswered; the zero time for an ask that names none.
func ExpiresAt(a oc.Ask) time.Time {
	t, err := occ.Time(a.Expires)
	if err != nil {
		return time.Time{}
	}
	return t
}