package keeper

import (
	"context"
	"errors"
	"fmt"
	"math/big"
	"time"

	colinearmath "colinear/x/colinearcore/math"
	"colinear/x/colinearcore/types"

	sdk "github.com/cosmos/cosmos-sdk/types"
)

func (k msgServer) ClaimFunds(goCtx context.Context, msg *types.MsgClaimFunds) (*types.MsgClaimFundsResponse, error) {
	ctx := sdk.UnwrapSDKContext(goCtx)

	// check that auction exists
	auction, found := k.Keeper.GetAuction(ctx, msg.AuctionId)
	if !found {
		return nil, fmt.Errorf("auction %s not found", msg.AuctionId)
	}

	// check that auction is finalized
	if auction.Best == nil {
		return nil, fmt.Errorf("auction %s is not finalized", msg.AuctionId)
	}

	// check that auction has remaining funds to pay out
	if auction.Remaining == "0" {
		return nil, fmt.Errorf("auction %s has no payable %s remaining", msg.AuctionId, auction.Denom)
	}

	// check that sender is the selected provider for the auction
	if auction.Best.Owner != msg.Creator {
		return nil, fmt.Errorf("lease reward is only claimable by selected provider (%s) (got %s)", auction.Best.Owner, msg.Creator)
	}

	// parse address to send to
	sendTo, err := sdk.AccAddressFromBech32(auction.Best.Owner)
	if err != nil {
		return nil, fmt.Errorf("failed to parse address %s: %s", auction.Best.Owner, err)
	}

	// calculate payable amount
	total := new(big.Int)
	total.SetString(auction.Best.Amount, 10)
	remaining := new(big.Int)
	remaining.SetString(auction.Remaining, 10)
	leaseBegin := time.Unix(int64(auction.LeaseStart), 0)
	leaseEnd := time.Unix(int64(auction.LeaseEnd), 0)
	now := ctx.BlockTime()
	subAmt, err := colinearmath.CalcAmountVestableLinear(total, remaining, now, leaseBegin, leaseEnd)
	if err != nil {
		return nil, errors.New("unable to calculate vestable amount")
	}

	// pay from module to user account
	coins := sdk.NewCoins(sdk.NewCoin(auction.Denom, sdk.NewIntFromBigInt(subAmt)))
	if err := k.bank.SendCoinsFromModuleToAccount(ctx, types.ModuleName, sendTo, coins); err != nil {
		return nil, fmt.Errorf("failed to send %s %s from module %s", subAmt.String(), auction.Denom, types.ModuleName)
	}

	// subtract paid amount off of remaining payout tally & commit to chain state
	newRemaining := new(big.Int)
	newRemaining.Sub(remaining, subAmt)
	auction.Remaining = subAmt.String()
	k.Keeper.SetAuction(ctx, auction)

	return &types.MsgClaimFundsResponse{}, nil
}