package rest

import (
	"bytes"
	"net/http"

	"github.com/gorilla/mux"

	"github.com/cosmos/cosmos-sdk/client/context"
	clientrest "github.com/cosmos/cosmos-sdk/client/rest"
	"github.com/cosmos/cosmos-sdk/codec"
	"github.com/cosmos/cosmos-sdk/crypto/keys"
	sdk "github.com/cosmos/cosmos-sdk/types"
	"github.com/cosmos/cosmos-sdk/types/rest"
	"github.com/cosmos/cosmos-sdk/x/staking"
)

func registerTxRoutes(cliCtx context.CLIContext, r *mux.Router, cdc *codec.Codec, kb keys.Keybase) {
	r.HandleFunc(
		"/staking/delegators/{delegatorAddr}/delegations",
		postDelegationsHandlerFn(cdc, kb, cliCtx),
	).Methods("POST")
	r.HandleFunc(
		"/staking/delegators/{delegatorAddr}/unbonding_delegations",
		postUnbondingDelegationsHandlerFn(cdc, kb, cliCtx),
	).Methods("POST")
	r.HandleFunc(
		"/staking/delegators/{delegatorAddr}/redelegations",
		postRedelegationsHandlerFn(cdc, kb, cliCtx),
	).Methods("POST")
}

type (
	// DelegateRequest defines the properties of a delegation request's body.
	DelegateRequest struct {
		BaseReq          rest.BaseReq   `json:"base_req"`
		DelegatorAddress sdk.AccAddress `json:"delegator_address"` // in bech32
		ValidatorAddress sdk.ValAddress `json:"validator_address"` // in bech32
		Amount           sdk.Coin       `json:"amount"`
	}

	// RedelegateRequest defines the properties of a redelegate request's body.
	RedelegateRequest struct {
		BaseReq             rest.BaseReq   `json:"base_req"`
		DelegatorAddress    sdk.AccAddress `json:"delegator_address"`     // in bech32
		ValidatorSrcAddress sdk.ValAddress `json:"validator_src_address"` // in bech32
		ValidatorDstAddress sdk.ValAddress `json:"validator_dst_address"` // in bech32
		Amount              sdk.Coin       `json:"amount"`
	}

	// UndelegateRequest defines the properties of a undelegate request's body.
	UndelegateRequest struct {
		BaseReq          rest.BaseReq   `json:"base_req"`
		DelegatorAddress sdk.AccAddress `json:"delegator_address"` // in bech32
		ValidatorAddress sdk.ValAddress `json:"validator_address"` // in bech32
		Amount           sdk.Coin       `json:"amount"`
	}
)

func postDelegationsHandlerFn(cdc *codec.Codec, kb keys.Keybase, cliCtx context.CLIContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req DelegateRequest

		if !rest.ReadRESTReq(w, r, cdc, &req) {
			return
		}

		req.BaseReq = req.BaseReq.Sanitize()
		if !req.BaseReq.ValidateBasic(w) {
			return
		}

		msg := staking.NewMsgDelegate(req.DelegatorAddress, req.ValidatorAddress, req.Amount)
		if err := msg.ValidateBasic(); err != nil {
			rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
			return
		}

		fromAddr, err := sdk.AccAddressFromBech32(req.BaseReq.From)
		if err != nil {
			rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
			return
		}

		if !bytes.Equal(fromAddr, req.DelegatorAddress) {
			rest.WriteErrorResponse(w, http.StatusUnauthorized, "must use own delegator address")
			return
		}

		clientrest.WriteGenerateStdTxResponse(w, cdc, cliCtx, req.BaseReq, []sdk.Msg{msg})
	}
}

func postRedelegationsHandlerFn(cdc *codec.Codec, kb keys.Keybase, cliCtx context.CLIContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req RedelegateRequest

		if !rest.ReadRESTReq(w, r, cdc, &req) {
			return
		}

		req.BaseReq = req.BaseReq.Sanitize()
		if !req.BaseReq.ValidateBasic(w) {
			return
		}

		msg := staking.NewMsgBeginRedelegate(req.DelegatorAddress, req.ValidatorSrcAddress, req.ValidatorDstAddress, req.Amount)
		if err := msg.ValidateBasic(); err != nil {
			rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
			return
		}

		fromAddr, err := sdk.AccAddressFromBech32(req.BaseReq.From)
		if err != nil {
			rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
			return
		}

		if !bytes.Equal(fromAddr, req.DelegatorAddress) {
			rest.WriteErrorResponse(w, http.StatusUnauthorized, "must use own delegator address")
			return
		}

		clientrest.WriteGenerateStdTxResponse(w, cdc, cliCtx, req.BaseReq, []sdk.Msg{msg})
	}
}

func postUnbondingDelegationsHandlerFn(cdc *codec.Codec, kb keys.Keybase, cliCtx context.CLIContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req UndelegateRequest

		if !rest.ReadRESTReq(w, r, cdc, &req) {
			return
		}

		req.BaseReq = req.BaseReq.Sanitize()
		if !req.BaseReq.ValidateBasic(w) {
			return
		}

		msg := staking.NewMsgUndelegate(req.DelegatorAddress, req.ValidatorAddress, req.Amount)
		if err := msg.ValidateBasic(); err != nil {
			rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
			return
		}

		fromAddr, err := sdk.AccAddressFromBech32(req.BaseReq.From)
		if err != nil {
			rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
			return
		}

		if !bytes.Equal(fromAddr, req.DelegatorAddress) {
			rest.WriteErrorResponse(w, http.StatusUnauthorized, "must use own delegator address")
			return
		}

		clientrest.WriteGenerateStdTxResponse(w, cdc, cliCtx, req.BaseReq, []sdk.Msg{msg})
	}
}