package client

import (
	"context"
	"crypto/tls"
	"fmt"
	"strings"
	"time"

	"github.com/tech/sendico/pkg/merrors"
	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials"
	"google.golang.org/grpc/credentials/insecure"
)

// Client exposes typed helpers around the payment orchestrator gRPC API.
type Client interface {
	QuotePayment(ctx context.Context, req *orchestratorv1.QuotePaymentRequest) (*orchestratorv1.QuotePaymentResponse, error)
	InitiatePayment(ctx context.Context, req *orchestratorv1.InitiatePaymentRequest) (*orchestratorv1.InitiatePaymentResponse, error)
	CancelPayment(ctx context.Context, req *orchestratorv1.CancelPaymentRequest) (*orchestratorv1.CancelPaymentResponse, error)
	GetPayment(ctx context.Context, req *orchestratorv1.GetPaymentRequest) (*orchestratorv1.GetPaymentResponse, error)
	ListPayments(ctx context.Context, req *orchestratorv1.ListPaymentsRequest) (*orchestratorv1.ListPaymentsResponse, error)
	InitiateConversion(ctx context.Context, req *orchestratorv1.InitiateConversionRequest) (*orchestratorv1.InitiateConversionResponse, error)
	ProcessTransferUpdate(ctx context.Context, req *orchestratorv1.ProcessTransferUpdateRequest) (*orchestratorv1.ProcessTransferUpdateResponse, error)
	ProcessDepositObserved(ctx context.Context, req *orchestratorv1.ProcessDepositObservedRequest) (*orchestratorv1.ProcessDepositObservedResponse, error)
	Close() error
}

type grpcOrchestratorClient interface {
	QuotePayment(ctx context.Context, in *orchestratorv1.QuotePaymentRequest, opts ...grpc.CallOption) (*orchestratorv1.QuotePaymentResponse, error)
	InitiatePayment(ctx context.Context, in *orchestratorv1.InitiatePaymentRequest, opts ...grpc.CallOption) (*orchestratorv1.InitiatePaymentResponse, error)
	CancelPayment(ctx context.Context, in *orchestratorv1.CancelPaymentRequest, opts ...grpc.CallOption) (*orchestratorv1.CancelPaymentResponse, error)
	GetPayment(ctx context.Context, in *orchestratorv1.GetPaymentRequest, opts ...grpc.CallOption) (*orchestratorv1.GetPaymentResponse, error)
	ListPayments(ctx context.Context, in *orchestratorv1.ListPaymentsRequest, opts ...grpc.CallOption) (*orchestratorv1.ListPaymentsResponse, error)
	InitiateConversion(ctx context.Context, in *orchestratorv1.InitiateConversionRequest, opts ...grpc.CallOption) (*orchestratorv1.InitiateConversionResponse, error)
	ProcessTransferUpdate(ctx context.Context, in *orchestratorv1.ProcessTransferUpdateRequest, opts ...grpc.CallOption) (*orchestratorv1.ProcessTransferUpdateResponse, error)
	ProcessDepositObserved(ctx context.Context, in *orchestratorv1.ProcessDepositObservedRequest, opts ...grpc.CallOption) (*orchestratorv1.ProcessDepositObservedResponse, error)
}

type orchestratorClient struct {
	cfg    Config
	conn   *grpc.ClientConn
	client grpcOrchestratorClient
}

// New dials the payment orchestrator endpoint and returns a ready client.
func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, error) {
	cfg.setDefaults()
	if strings.TrimSpace(cfg.Address) == "" {
		return nil, merrors.InvalidArgument("payment-orchestrator: address is required")
	}

	dialCtx, cancel := context.WithTimeout(ctx, cfg.DialTimeout)
	defer cancel()

	dialOpts := make([]grpc.DialOption, 0, len(opts)+1)
	dialOpts = append(dialOpts, opts...)

	if cfg.Insecure {
		dialOpts = append(dialOpts, grpc.WithTransportCredentials(insecure.NewCredentials()))
	} else {
		dialOpts = append(dialOpts, grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{})))
	}

	conn, err := grpc.DialContext(dialCtx, cfg.Address, dialOpts...)
	if err != nil {
		return nil, merrors.InternalWrap(err, fmt.Sprintf("payment-orchestrator: dial %s", cfg.Address))
	}

	return &orchestratorClient{
		cfg:    cfg,
		conn:   conn,
		client: orchestratorv1.NewPaymentOrchestratorClient(conn),
	}, nil
}

// NewWithClient injects a pre-built orchestrator client (useful for tests).
func NewWithClient(cfg Config, oc grpcOrchestratorClient) Client {
	cfg.setDefaults()
	return &orchestratorClient{
		cfg:    cfg,
		client: oc,
	}
}

func (c *orchestratorClient) Close() error {
	if c.conn != nil {
		return c.conn.Close()
	}
	return nil
}

func (c *orchestratorClient) QuotePayment(ctx context.Context, req *orchestratorv1.QuotePaymentRequest) (*orchestratorv1.QuotePaymentResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.QuotePayment(ctx, req)
}

func (c *orchestratorClient) InitiatePayment(ctx context.Context, req *orchestratorv1.InitiatePaymentRequest) (*orchestratorv1.InitiatePaymentResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.InitiatePayment(ctx, req)
}

func (c *orchestratorClient) CancelPayment(ctx context.Context, req *orchestratorv1.CancelPaymentRequest) (*orchestratorv1.CancelPaymentResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.CancelPayment(ctx, req)
}

func (c *orchestratorClient) GetPayment(ctx context.Context, req *orchestratorv1.GetPaymentRequest) (*orchestratorv1.GetPaymentResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.GetPayment(ctx, req)
}

func (c *orchestratorClient) ListPayments(ctx context.Context, req *orchestratorv1.ListPaymentsRequest) (*orchestratorv1.ListPaymentsResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.ListPayments(ctx, req)
}

func (c *orchestratorClient) InitiateConversion(ctx context.Context, req *orchestratorv1.InitiateConversionRequest) (*orchestratorv1.InitiateConversionResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.InitiateConversion(ctx, req)
}

func (c *orchestratorClient) ProcessTransferUpdate(ctx context.Context, req *orchestratorv1.ProcessTransferUpdateRequest) (*orchestratorv1.ProcessTransferUpdateResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.ProcessTransferUpdate(ctx, req)
}

func (c *orchestratorClient) ProcessDepositObserved(ctx context.Context, req *orchestratorv1.ProcessDepositObservedRequest) (*orchestratorv1.ProcessDepositObservedResponse, error) {
	ctx, cancel := c.callContext(ctx)
	defer cancel()
	return c.client.ProcessDepositObserved(ctx, req)
}

func (c *orchestratorClient) callContext(ctx context.Context) (context.Context, context.CancelFunc) {
	timeout := c.cfg.CallTimeout
	if timeout <= 0 {
		timeout = 3 * time.Second
	}
	return context.WithTimeout(ctx, timeout)
}