// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package consoleapi

import (
	"encoding/json"
	"io"
	"io/ioutil"
	"net/http"
	"strconv"
	"time"

	"github.com/gorilla/mux"
	"github.com/spacemonkeygo/monkit/v3"
	"github.com/zeebo/errs"
	"go.uber.org/zap"

	"storj.io/storj/satellite/console"
)

var (
	// ErrPaymentsAPI - console payments api error type.
	ErrPaymentsAPI = errs.Class("consoleapi payments")
	mon            = monkit.Package()
)

// Payments is an api controller that exposes all payment related functionality.
type Payments struct {
	log     *zap.Logger
	service *console.Service
}

// NewPayments is a constructor for api payments controller.
func NewPayments(log *zap.Logger, service *console.Service) *Payments {
	return &Payments{
		log:     log,
		service: service,
	}
}

// SetupAccount creates a payment account for the user.
func (p *Payments) SetupAccount(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	err = p.service.Payments().SetupAccount(ctx)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}
}

// AccountBalance returns an integer amount in cents that represents the current balance of payment account.
func (p *Payments) AccountBalance(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	w.Header().Set("Content-Type", "application/json")

	balance, err := p.service.Payments().AccountBalance(ctx)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}

	err = json.NewEncoder(w).Encode(&balance)
	if err != nil {
		p.log.Error("failed to write json balance response", zap.Error(ErrPaymentsAPI.Wrap(err)))
	}
}

// ProjectsCharges returns how much money current user will be charged for each project which he owns.
func (p *Payments) ProjectsCharges(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	w.Header().Set("Content-Type", "application/json")

	sinceStamp, err := strconv.ParseInt(r.URL.Query().Get("from"), 10, 64)
	if err != nil {
		p.serveJSONError(w, http.StatusBadRequest, err)
		return
	}
	beforeStamp, err := strconv.ParseInt(r.URL.Query().Get("to"), 10, 64)
	if err != nil {
		p.serveJSONError(w, http.StatusBadRequest, err)
		return
	}

	since := time.Unix(sinceStamp, 0).UTC()
	before := time.Unix(beforeStamp, 0).UTC()

	charges, err := p.service.Payments().ProjectsCharges(ctx, since, before)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}

	err = json.NewEncoder(w).Encode(charges)
	if err != nil {
		p.log.Error("failed to write json response", zap.Error(ErrPaymentsAPI.Wrap(err)))
	}
}

// AddCreditCard is used to save new credit card and attach it to payment account.
func (p *Payments) AddCreditCard(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	bodyBytes, err := ioutil.ReadAll(r.Body)
	if err != nil {
		p.serveJSONError(w, http.StatusBadRequest, err)
		return
	}

	token := string(bodyBytes)

	err = p.service.Payments().AddCreditCard(ctx, token)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}
}

// ListCreditCards returns a list of credit cards for a given payment account.
func (p *Payments) ListCreditCards(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	w.Header().Set("Content-Type", "application/json")

	cards, err := p.service.Payments().ListCreditCards(ctx)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}

	err = json.NewEncoder(w).Encode(cards)
	if err != nil {
		p.log.Error("failed to write json list cards response", zap.Error(ErrPaymentsAPI.Wrap(err)))
	}
}

// MakeCreditCardDefault makes a credit card default payment method.
func (p *Payments) MakeCreditCardDefault(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	cardID, err := ioutil.ReadAll(r.Body)
	if err != nil {
		p.serveJSONError(w, http.StatusBadRequest, err)
		return
	}

	err = p.service.Payments().MakeCreditCardDefault(ctx, string(cardID))
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}
}

// RemoveCreditCard is used to detach a credit card from payment account.
func (p *Payments) RemoveCreditCard(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	vars := mux.Vars(r)
	cardID := vars["cardId"]

	if cardID == "" {
		p.serveJSONError(w, http.StatusBadRequest, err)
		return
	}

	err = p.service.Payments().RemoveCreditCard(ctx, cardID)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}
}

// BillingHistory returns a list of invoices, transactions and all others billing history items for payment account.
func (p *Payments) BillingHistory(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	w.Header().Set("Content-Type", "application/json")

	billingHistory, err := p.service.Payments().BillingHistory(ctx)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}

	err = json.NewEncoder(w).Encode(billingHistory)
	if err != nil {
		p.log.Error("failed to write json billing history response", zap.Error(ErrPaymentsAPI.Wrap(err)))
	}
}

// TokenDeposit creates new deposit transaction and info about address and amount of newly created tx.
func (p *Payments) TokenDeposit(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error

	defer mon.Task()(&ctx)(&err)

	w.Header().Set("Content-Type", "application/json")

	var requestData struct {
		Amount int64 `json:"amount"`
	}

	if err = json.NewDecoder(r.Body).Decode(&requestData); err != nil {
		p.serveJSONError(w, http.StatusBadRequest, err)
		return
	}

	if requestData.Amount < 0 {
		p.serveJSONError(w, http.StatusBadRequest, errs.New("amount can not be negative"))
		return
	}
	if requestData.Amount == 0 {
		p.serveJSONError(w, http.StatusBadRequest, errs.New("amount should be greater than zero"))
		return
	}

	tx, err := p.service.Payments().TokenDeposit(ctx, requestData.Amount)
	if err != nil {
		if console.ErrUnauthorized.Has(err) {
			p.serveJSONError(w, http.StatusUnauthorized, err)
			return
		}

		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}

	var responseData struct {
		Address     string    `json:"address"`
		Amount      float64   `json:"amount"`
		TokenAmount string    `json:"tokenAmount"`
		Rate        string    `json:"rate"`
		Status      string    `json:"status"`
		Link        string    `json:"link"`
		ExpiresAt   time.Time `json:"expires"`
	}

	responseData.Address = tx.Address
	responseData.Amount = float64(requestData.Amount) / 100
	responseData.TokenAmount = tx.Amount.String()
	responseData.Rate = tx.Rate.Text('f', 8)
	responseData.Status = tx.Status.String()
	responseData.Link = tx.Link
	responseData.ExpiresAt = tx.CreatedAt.Add(tx.Timeout)

	err = json.NewEncoder(w).Encode(responseData)
	if err != nil {
		p.log.Error("failed to write json token deposit response", zap.Error(ErrPaymentsAPI.Wrap(err)))
	}
}

// ApplyCouponCode applies a coupon code to the user's account.
func (p *Payments) ApplyCouponCode(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	var err error
	defer mon.Task()(&ctx)(&err)

	// limit the size of the body to prevent excessive memory usage
	bodyBytes, err := ioutil.ReadAll(io.LimitReader(r.Body, 1*1024*1024))
	if err != nil {
		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}
	couponCode := string(bodyBytes)

	err = p.service.Payments().ApplyCouponCode(ctx, couponCode)
	if err != nil {
		p.serveJSONError(w, http.StatusInternalServerError, err)
		return
	}
}

// serveJSONError writes JSON error to response output stream.
func (p *Payments) serveJSONError(w http.ResponseWriter, status int, err error) {
	serveJSONError(p.log, w, status, err)
}