package handoff

import (
	"context"
	"fmt"
)

type ARIClient interface {
	RedirectChannel(ctx context.Context, channelID string, endpoint string) error
	ContinueInDialplan(ctx context.Context, channelID, dialplanContext, extension string, priority int) error
}

type Executor interface {
	Execute(ctx context.Context, req HandoffRequest) (HandoffResult, error)
}

type SafeExecutor struct {
	ARI ARIClient
}

func (e SafeExecutor) Execute(ctx context.Context, req HandoffRequest) (HandoffResult, error) {
	result := HandoffResult{RequestID: req.ID, Mode: req.Mode}
	switch req.Mode {
	case HandoffModeDisabledStub:
		result.Status = HandoffStatusStubbed
		result.MessageKey = "handoff.stub"
		result.Message = Message(result.MessageKey, req.Language)
		return result, nil
	case HandoffModeHangupAfterMessage:
		result.Status = HandoffStatusCompleted
		result.MessageKey = "handoff.stub"
		result.Message = Message(result.MessageKey, req.Language)
		return result, nil
	case HandoffModeARIRedirect:
		result.TransferAttempted = true
		if e.ARI == nil {
			return transferFailed(req, "ari client not configured")
		}
		if err := e.ARI.RedirectChannel(ctx, req.AsteriskChannelID, req.TargetEndpoint); err != nil {
			return transferFailed(req, err.Error())
		}
		result.Status = HandoffStatusCompleted
		result.TransferSucceeded = true
		result.MessageKey = "handoff.transfer_started"
		result.Message = Message(result.MessageKey, req.Language)
		return result, nil
	case HandoffModeDialplanContinue:
		result.TransferAttempted = true
		if e.ARI == nil {
			return transferFailed(req, "ari client not configured")
		}
		if err := e.ARI.ContinueInDialplan(ctx, req.AsteriskChannelID, req.DialplanContext, req.DialplanExtension, req.DialplanPriority); err != nil {
			return transferFailed(req, err.Error())
		}
		result.Status = HandoffStatusCompleted
		result.TransferSucceeded = true
		result.MessageKey = "handoff.transfer_started"
		result.Message = Message(result.MessageKey, req.Language)
		return result, nil
	default:
		return HandoffResult{RequestID: req.ID, Mode: req.Mode, Status: HandoffStatusFailed, MessageKey: "handoff.denied", Message: Message("handoff.denied", req.Language), Error: "unknown handoff mode"}, fmt.Errorf("unknown handoff mode")
	}
}

func transferFailed(req HandoffRequest, msg string) (HandoffResult, error) {
	result := HandoffResult{RequestID: req.ID, Mode: req.Mode, Status: HandoffStatusFailed, TransferAttempted: true, MessageKey: "handoff.transfer_failed", Message: Message("handoff.transfer_failed", req.Language), Error: SanitizeText(msg, 200)}
	return result, fmt.Errorf("handoff transfer failed")
}