package full

import (
	"context"
	"fmt"
	"github.com/filecoin-project/go-lotus/chain/types"
	"github.com/filecoin-project/go-lotus/chain/vm"
	"golang.org/x/xerrors"
	"strconv"

	"github.com/filecoin-project/go-lotus/api"
	"github.com/filecoin-project/go-lotus/chain/actors"
	"github.com/filecoin-project/go-lotus/chain/address"
	"github.com/filecoin-project/go-lotus/chain/state"
	"github.com/filecoin-project/go-lotus/chain/store"

	"github.com/ipfs/go-hamt-ipld"
	cbor "github.com/ipfs/go-ipld-cbor"
	"go.uber.org/fx"
)

type StateAPI struct {
	fx.In

	Chain *store.ChainStore
}

func (a *StateAPI) StateMinerSectors(ctx context.Context, addr address.Address) ([]*api.SectorInfo, error) {
	ts := a.Chain.GetHeaviestTipSet()

	stc, err := a.Chain.TipSetState(ts.Cids())
	if err != nil {
		return nil, err
	}

	cst := hamt.CSTFromBstore(a.Chain.Blockstore())

	st, err := state.LoadStateTree(cst, stc)
	if err != nil {
		return nil, err
	}

	act, err := st.GetActor(addr)
	if err != nil {
		return nil, err
	}

	var minerState actors.StorageMinerActorState
	if err := cst.Get(ctx, act.Head, &minerState); err != nil {
		return nil, err
	}

	nd, err := hamt.LoadNode(ctx, cst, minerState.Sectors)
	if err != nil {
		return nil, err
	}

	var sinfos []*api.SectorInfo
	// Note to self: the hamt isnt a great data structure to use here... need to implement the sector set
	err = nd.ForEach(ctx, func(k string, val interface{}) error {
		sid, err := strconv.ParseUint(k, 10, 64)
		if err != nil {
			return err
		}

		bval, ok := val.([]byte)
		if !ok {
			return fmt.Errorf("expected to get bytes in sector set hamt")
		}

		var comms [][]byte
		if err := cbor.DecodeInto(bval, &comms); err != nil {
			return err
		}

		sinfos = append(sinfos, &api.SectorInfo{
			SectorID: sid,
			CommR:    comms[0],
			CommD:    comms[1],
		})
		return nil
	})
	return sinfos, nil
}

func (a *StateAPI) StateMinerProvingSet(ctx context.Context, addr address.Address) ([]*api.SectorInfo, error) {
	ts := a.Chain.GetHeaviestTipSet()

	stc, err := a.Chain.TipSetState(ts.Cids())
	if err != nil {
		return nil, err
	}

	cst := hamt.CSTFromBstore(a.Chain.Blockstore())

	st, err := state.LoadStateTree(cst, stc)
	if err != nil {
		return nil, err
	}

	act, err := st.GetActor(addr)
	if err != nil {
		return nil, err
	}

	var minerState actors.StorageMinerActorState
	if err := cst.Get(ctx, act.Head, &minerState); err != nil {
		return nil, err
	}

	nd, err := hamt.LoadNode(ctx, cst, minerState.ProvingSet)
	if err != nil {
		return nil, err
	}

	var sinfos []*api.SectorInfo
	// Note to self: the hamt isnt a great data structure to use here... need to implement the sector set
	err = nd.ForEach(ctx, func(k string, val interface{}) error {
		sid, err := strconv.ParseUint(k, 10, 64)
		if err != nil {
			return err
		}

		bval, ok := val.([]byte)
		if !ok {
			return fmt.Errorf("expected to get bytes in sector set hamt")
		}

		var comms [][]byte
		if err := cbor.DecodeInto(bval, &comms); err != nil {
			return err
		}

		sinfos = append(sinfos, &api.SectorInfo{
			SectorID: sid,
			CommR:    comms[0],
			CommD:    comms[1],
		})
		return nil
	})
	return sinfos, nil
}

func (a *StateAPI) StateMinerPower(ctx context.Context, maddr address.Address, ts *types.TipSet) (api.MinerPower, error) {
	var err error
	enc, err := actors.SerializeParams(&actors.PowerLookupParams{maddr})
	if err != nil {
		return api.MinerPower{}, err
	}

	var mpow types.BigInt

	if maddr != address.Undef {
		ret, err := vm.Call(ctx, a.Chain, &types.Message{
			From:   maddr,
			To:     actors.StorageMarketAddress,
			Method: actors.SMAMethods.PowerLookup,
			Params: enc,
		}, ts)
		if err != nil {
			return api.MinerPower{}, xerrors.Errorf("failed to get miner power from chain: %w", err)
		}
		if ret.ExitCode != 0 {
			return api.MinerPower{}, xerrors.Errorf("failed to get miner power from chain (exit code %d)", ret.ExitCode)
		}

		mpow = types.BigFromBytes(ret.Return)
	}

	ret, err := vm.Call(ctx, a.Chain, &types.Message{
		From:   actors.StorageMarketAddress,
		To:     actors.StorageMarketAddress,
		Method: actors.SMAMethods.GetTotalStorage,
	}, ts)
	if err != nil {
		return api.MinerPower{}, xerrors.Errorf("failed to get total power from chain: %w", err)
	}
	if ret.ExitCode != 0 {
		return api.MinerPower{}, xerrors.Errorf("failed to get total power from chain (exit code %d)", ret.ExitCode)
	}

	tpow := types.BigFromBytes(ret.Return)

	return api.MinerPower{
		MinerPower: mpow,
		TotalPower: tpow,
	}, nil
}