package sendico

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"net/http"
	"time"

	"git.sendico.io/tech/sxchnge/product/payments"
	merrors "git.sendico.io/tech/sxchnge/shared/errors"
)

type moneyDTO struct {
	Amount   string `json:"amount"`
	Currency string `json:"currency"`
}
type endpointDTO struct {
	Type string            `json:"type"`
	Data map[string]string `json:"data"`
}

// Explicit wire fields avoid coupling local domain models to provider JSON.
type quoteRequestDTO struct {
	Key    string           `json:"idempotencyKey"`
	Intent paymentIntentDTO `json:"intent"`
}
type paymentIntentDTO struct {
	Kind         string      `json:"kind"`
	Source       endpointDTO `json:"source"`
	Destination  endpointDTO `json:"destination"`
	Amount       moneyDTO    `json:"amount"`
	Subject      string      `json:"external_subject_ref"`
	FeeTreatment string      `json:"fee_treatment"`
}
type quoteAmountsDTO struct {
	Principal moneyDTO `json:"sourcePrincipal"`
	Debit     moneyDTO `json:"sourceDebitTotal"`
	Credit    moneyDTO `json:"destinationSettlement"`
}
type paymentQuoteDTO struct {
	ID          string          `json:"quoteRef"`
	State       string          `json:"state"`
	Executable  bool            `json:"executable"`
	BlockReason string          `json:"blockReason"`
	Expires     time.Time       `json:"expiresAt"`
	Amounts     quoteAmountsDTO `json:"amounts"`
}
type paymentDTO struct {
	ID      string          `json:"paymentRef"`
	State   string          `json:"state"`
	Quote   paymentQuoteDTO `json:"lastQuote"`
	Created time.Time       `json:"createdAt"`
}
type accountDTO struct {
	ID         string            `json:"ledgerAccountRef"`
	ScopeRef   string            `json:"organizationRef"`
	Owner      string            `json:"ownerRef"`
	Currency   string            `json:"currency"`
	Type       string            `json:"accountType"`
	LedgerRole string            `json:"role"`
	Status     string            `json:"status"`
	Metadata   map[string]string `json:"metadata"`
}
type currencyDTO struct {
	Code  string `json:"code"`
	Scale *int   `json:"accountingScale"`
}
type balanceDTO struct {
	ID    string   `json:"ledgerAccountRef"`
	Money moneyDTO `json:"balance"`
}

func (c *Client) paymentRequest(ctx context.Context, method, path string, payload, dst any) error {
	token, err := c.token()
	if err != nil {
		return err
	}
	var body []byte
	if payload != nil {
		body, err = json.Marshal(payload)
		if err != nil {
			return merrors.OpaqueWrap(payments.Unavailable, err, "encode Sendico payment request")
		}
	}
	req, err := http.NewRequestWithContext(ctx, method, c.base+path, bytes.NewReader(body))
	if err != nil {
		return merrors.OpaqueWrap(payments.Unavailable, err, "create Sendico payment request")
	}
	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("Content-Type", "application/json")
	client := *c.http
	client.Timeout = 30 * time.Second
	res, err := client.Do(req)
	if err != nil {
		return merrors.OpaqueWrap(payments.Unavailable, err, "Sendico payment request failed")
	}
	defer func() { _ = res.Body.Close() }()
	// Never forward upstream errors, credentials, or arbitrary error bodies.
	if res.StatusCode != http.StatusOK {
		return payments.Unavailable
	}
	var envelope struct {
		Status string          `json:"status"`
		Data   json.RawMessage `json:"data"`
	}
	d := json.NewDecoder(io.LimitReader(res.Body, 4*1024*1024+1))
	if err = d.Decode(&envelope); err != nil {
		return merrors.OpaqueWrap(payments.Unavailable, err, "decode Sendico payment envelope")
	}
	if envelope.Status != "success" {
		return payments.Unavailable
	}
	var extra any
	if d.Decode(&extra) != io.EOF {
		return payments.Unavailable
	}
	if err = json.Unmarshal(envelope.Data, dst); err != nil {
		return merrors.OpaqueWrap(payments.Unavailable, err, "decode Sendico payment payload")
	}
	return nil
}