package paymenthttp

import (
	"encoding/json"
	"errors"
	"io"
	"net/http"
	"strconv"

	sresponse "git.sendico.io/tech/sxchnge/product/auth/http/v1/response"
	"git.sendico.io/tech/sxchnge/product/auth/ipguard"
	customer "git.sendico.io/tech/sxchnge/product/customers/model"
	"git.sendico.io/tech/sxchnge/product/payments"
	verification "git.sendico.io/tech/sxchnge/product/verification/store"
	merrors "git.sendico.io/tech/sxchnge/shared/errors"
	api "git.sendico.io/tech/sxchnge/shared/http"
	"git.sendico.io/tech/sxchnge/shared/http/response"
	mlogger "git.sendico.io/tech/sxchnge/shared/logging"
	mservice "git.sendico.io/tech/sxchnge/shared/service"
)

type Registrar interface {
	AccountHandler(mservice.Type, string, api.HTTPMethod, sresponse.AccountHandlerFunc)
}
type router struct {
	service *payments.Service
	logger  mlogger.Logger
}

func Install(reg Registrar, s *payments.Service, logger mlogger.Logger) {
	h := &router{s, logger.Named("payment_http")}
	reg.AccountHandler(mservice.Accounts, "/wallet/profile", api.Get, h.profile)
	reg.AccountHandler(mservice.Accounts, "/wallet", api.Get, h.fetch)
	reg.AccountHandler(mservice.Accounts, "/wallet/quote", api.Post, h.quote)
	reg.AccountHandler(mservice.Accounts, "/wallet/submit", api.Post, h.submit)
	reg.AccountHandler(mservice.Accounts, "/wallet/submission", api.Post, h.reconcile)
	reg.AccountHandler(mservice.Accounts, "/wallet/challenge", api.Post, h.challenge)
	reg.AccountHandler(mservice.Accounts, "/wallet/resend", api.Post, h.resend)
	reg.AccountHandler(mservice.Accounts, "/wallet/verify", api.Post, h.verify)
}
func decode(r *http.Request, dst any) error {
	d := json.NewDecoder(io.LimitReader(r.Body, 8193))
	d.DisallowUnknownFields()
	if d.Decode(dst) != nil {
		return payments.InvalidAmount
	}
	var extra any
	if d.Decode(&extra) != io.EOF {
		return payments.InvalidAmount
	}
	return nil
}
func (h *router) result(data any, err error) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Cache-Control", "no-store")
		if err == nil {
			response.Ok(h.logger, data)(w, r)
			return
		}
		code := "unavailable"
		status := http.StatusServiceUnavailable
		var f payments.Failure
		if errors.As(err, &f) {
			code = string(f)
			if f != payments.Unavailable && f != payments.Uncertain {
				status = http.StatusBadRequest
			}
		}
		switch {
		case errors.Is(err, verification.ErrTokenExpired):
			code = "factorExpired"
			status = 400
		case errors.Is(err, verification.ErrTokenAttemptsExceeded):
			code = "factorLocked"
			status = 400
		case errors.Is(err, verification.ErrTokenNotFound), errors.Is(err, verification.ErrTokenAlreadyUsed), errors.Is(err, merrors.ErrUnauthorized):
			code = "factorInvalid"
			status = 400
		}
		if throttle, ok := verification.Throttle(err); ok {
			w.Header().Set("Retry-After", strconv.Itoa(max(1, int(throttle.RetryAfter.Seconds()))))
			code = "factorCooldown"
			status = 429
		}
		response.Error(h.logger, mservice.Accounts, status, code, "Unable to complete wallet operation")(w, r)
	}
}
func (h *router) fetch(r *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	v, e := h.service.Fetch(r.Context(), a)
	return h.result(fromSnapshot(v), e)
}
func (h *router) quote(r *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	var d requestDTO
	if e := decode(r, &d); e != nil {
		return h.result(nil, e)
	}
	v, e := h.service.Quote(r.Context(), a, d.model())
	return h.result(fromQuote(v), e)
}

type actionDTO struct {
	Quote     string `json:"quoteId"`
	Key       string `json:"idempotencyKey"`
	Challenge string `json:"challengeId"`
	Code      string `json:"code"`
}

func (h *router) submit(r *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	var d actionDTO
	if e := decode(r, &d); e != nil {
		return h.result(nil, e)
	}
	v, e := h.service.Submit(r.Context(), a, d.Quote, d.Key)
	return h.result(fromOperation(v), e)
}
func (h *router) reconcile(r *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	var d actionDTO
	if e := decode(r, &d); e != nil {
		return h.result(nil, e)
	}
	v, e := h.service.Reconcile(r.Context(), a, d.Key)
	if v == nil {
		return h.result(nil, e)
	}
	return h.result(fromOperation(*v), e)
}
func requestIP(r *http.Request) string {
	if ip := ipguard.ClientIP(r); ip != nil {
		return ip.String()
	}
	return "unresolved"
}
func (h *router) challenge(r *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	var d actionDTO
	if e := decode(r, &d); e != nil {
		return h.result(nil, e)
	}
	v, e := h.service.Challenge(r.Context(), a, d.Quote, requestIP(r))
	return h.result(fromChallenge(v), e)
}
func (h *router) resend(r *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	var d actionDTO
	if e := decode(r, &d); e != nil {
		return h.result(nil, e)
	}
	v, e := h.service.Resend(r.Context(), a, d.Quote, d.Challenge, d.Key, requestIP(r))
	return h.result(fromChallenge(v), e)
}
func (h *router) verify(r *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	var d actionDTO
	if e := decode(r, &d); e != nil {
		return h.result(nil, e)
	}
	e := h.service.Authorize(r.Context(), a, d.Quote, d.Challenge, d.Code, d.Key)
	return h.result(struct {
		Key string `json:"idempotencyKey"`
	}{d.Key}, e)
}

func (h *router) profile(_ *http.Request, a *customer.Account, _ *sresponse.TokenData) http.HandlerFunc {
	return h.result(struct {
		Locale string `json:"locale"`
	}{a.Locale}, nil)
}