package lpwindow

import (
	"context"
	"github.com/filecoin-project/go-address"
	"github.com/filecoin-project/go-state-types/builtin/v9/miner"
	"github.com/filecoin-project/lotus/api"
	"github.com/filecoin-project/lotus/storage/wdpost"
	logging "github.com/ipfs/go-log/v2"
	"golang.org/x/xerrors"
	"sort"
	"time"

	"github.com/filecoin-project/go-state-types/abi"
	"github.com/filecoin-project/go-state-types/dline"
	"github.com/filecoin-project/lotus/chain/types"
	"github.com/filecoin-project/lotus/lib/harmony/harmonydb"
	"github.com/filecoin-project/lotus/lib/harmony/harmonytask"
	"github.com/filecoin-project/lotus/lib/harmony/resources"
	"github.com/filecoin-project/lotus/lib/harmony/taskhelp"
	"github.com/filecoin-project/lotus/storage/sealer/sealtasks"
	"github.com/filecoin-project/lotus/storage/sealer/storiface"
	"github.com/samber/lo"
)

var log = logging.Logger("lpwindow")

var EpochsPerDeadline = miner.WPoStProvingPeriod / abi.ChainEpoch(miner.WPoStPeriodDeadlines)

type WdPostTaskDetails struct {
	Ts       *types.TipSet
	Deadline *dline.Info
}

type WDPoStAPI interface {
	ChainHead(context.Context) (*types.TipSet, error)
	ChainGetTipSet(context.Context, types.TipSetKey) (*types.TipSet, error)
	StateMinerProvingDeadline(context.Context, address.Address, types.TipSetKey) (*dline.Info, error)
	StateMinerInfo(context.Context, address.Address, types.TipSetKey) (api.MinerInfo, error)
	ChainGetTipSetAfterHeight(context.Context, abi.ChainEpoch, types.TipSetKey) (*types.TipSet, error)
}

type WdPostTask struct {
	api WDPoStAPI

	db  *harmonydb.DB
	max int
}

func (t *WdPostTask) Do(taskID harmonytask.TaskID, stillOwned func() bool) (done bool, err error) {

	time.Sleep(5 * time.Second)
	log.Errorf("WdPostTask.Do() called with taskID: %v", taskID)

	var deadline dline.Info

	var spID, pps, dlIdx, partIdx uint64

	err = t.db.QueryRow(context.Background(),
		`Select sp_id, proving_period_start, deadline_index, partition_index
			from wdpost_tasks 
			where task_id = $1`, taskID).Scan(
		&spID, &pps, &dlIdx, &partIdx,
	)
	if err != nil {
		log.Errorf("WdPostTask.Do() failed to queryRow: %v", err)
		return false, err
	}

	head, err := t.api.ChainHead(context.Background())
	if err != nil {
		log.Errorf("WdPostTask.Do() failed to get chain head: %v", err)
		return false, err
	}

	wdpost.NewDeadlineInfo(abi.ChainEpoch(pps), dlIdx, head.Height())

	if deadline.PeriodElapsed() {
		log.Errorf("WdPost removed stale task: %v %v", taskID, deadline)
		return true, nil
	}

	panic("todo")

	/*submitWdPostParams, err := t.Scheduler.runPoStCycle(context.Background(), false, deadline, ts)
		if err != nil {
			log.Errorf("WdPostTask.Do() failed to runPoStCycle: %v", err)
			return false, err
		}

		log.Errorf("WdPostTask.Do() called with taskID: %v, submitWdPostParams: %v", taskID, submitWdPostParams)

		// Enter an entry for each wdpost message proof into the wdpost_proofs table
		for _, params := range submitWdPostParams {

			// Convert submitWdPostParams.Partitions to a byte array using CBOR
			buf := new(bytes.Buffer)
			scratch := make([]byte, 9)
			if err := cbg.WriteMajorTypeHeaderBuf(scratch, buf, cbg.MajArray, uint64(len(params.Partitions))); err != nil {
				return false, err
			}
			for _, v := range params.Partitions {
				if err := v.MarshalCBOR(buf); err != nil {
					return false, err
				}
			}

			// Insert into wdpost_proofs table
			_, err = t.db.Exec(context.Background(),
				`INSERT INTO wdpost_proofs (
	                           deadline,
	                           partitions,
	                           proof_type,
	                           proof_bytes)
	    			 VALUES ($1, $2, $3, $4)`,
				params.Deadline,
				buf.Bytes(),
				params.Proofs[0].PoStProof,
				params.Proofs[0].ProofBytes)
		}*/

	return true, nil
}

func (t *WdPostTask) CanAccept(ids []harmonytask.TaskID, te *harmonytask.TaskEngine) (*harmonytask.TaskID, error) {
	// GetEpoch
	ts, err := t.api.ChainHead(context.Background())

	if err != nil {
		return nil, err
	}

	// GetData for tasks
	type wdTaskDef struct {
		Task_id              harmonytask.TaskID
		Sp_id                uint64
		Proving_period_start abi.ChainEpoch
		Deadline_index       uint64
		Partition_index      uint64

		dlInfo *dline.Info `pgx:"-"`
		openTs *types.TipSet
	}
	var tasks []wdTaskDef

	err = t.db.Select(context.Background(), &tasks,
		`Select 
			task_id,
			sp_id,
			proving_period_start,
			deadline_index,
			partition_index
	from wdpost_tasks 
	where task_id IN $1`, ids)
	if err != nil {
		return nil, err
	}

	// Accept those past deadline, then delete them in Do().
	for i := range tasks {
		tasks[i].dlInfo = wdpost.NewDeadlineInfo(tasks[i].Proving_period_start, tasks[i].Deadline_index, ts.Height())

		if tasks[i].dlInfo.PeriodElapsed() {
			return &tasks[i].Task_id, nil
		}

		tasks[i].openTs, err = t.api.ChainGetTipSetAfterHeight(context.Background(), tasks[i].dlInfo.Open, ts.Key())
		if err != nil {
			return nil, xerrors.Errorf("getting task open tipset: %w", err)
		}
	}

	// Discard those too big for our free RAM
	freeRAM := te.ResourcesAvailable().Ram
	tasks = lo.Filter(tasks, func(d wdTaskDef, _ int) bool {
		maddr, err := address.NewIDAddress(tasks[0].Sp_id)
		if err != nil {
			log.Errorf("WdPostTask.CanAccept() failed to NewIDAddress: %v", err)
			return false
		}

		mi, err := t.api.StateMinerInfo(context.Background(), maddr, ts.Key())
		if err != nil {
			log.Errorf("WdPostTask.CanAccept() failed to StateMinerInfo: %v", err)
			return false
		}

		return res[mi.WindowPoStProofType].MaxMemory <= freeRAM
	})
	if len(tasks) == 0 {
		log.Infof("RAM too small for any WDPost task")
		return nil, nil
	}

	// Ignore those with too many failures unless they are the only ones left.
	tasks, _ = taskhelp.SliceIfFound(tasks, func(d wdTaskDef) bool {
		var r int
		err := t.db.QueryRow(context.Background(), `SELECT COUNT(*) 
		FROM harmony_task_history 
		WHERE task_id = $1 AND success = false`, d.Task_id).Scan(&r)
		if err != nil {
			log.Errorf("WdPostTask.CanAccept() failed to queryRow: %v", err)
		}
		return r < 2
	})

	// Select the one closest to the deadline
	sort.Slice(tasks, func(i, j int) bool {
		return tasks[i].dlInfo.Open < tasks[j].dlInfo.Open
	})

	return &tasks[0].Task_id, nil
}

var res = storiface.ResourceTable[sealtasks.TTGenerateWindowPoSt]

func (t *WdPostTask) TypeDetails() harmonytask.TaskTypeDetails {
	return harmonytask.TaskTypeDetails{
		Name:        "WdPost",
		Max:         t.max,
		MaxFailures: 3,
		Follows:     nil,
		Cost: resources.Resources{
			Cpu: 1,
			Gpu: 1,
			// RAM of smallest proof's max is listed here
			Ram: lo.Reduce(lo.Keys(res), func(i uint64, k abi.RegisteredSealProof, _ int) uint64 {
				if res[k].MaxMemory < i {
					return res[k].MaxMemory
				}
				return i
			}, 1<<63),
		},
	}
}

func (t *WdPostTask) Adder(taskFunc harmonytask.AddTaskFunc) {

	// wait for any channels on t.tasks and call taskFunc on them
	for taskDetails := range t.tasks {

		//log.Errorf("WdPostTask.Adder() received taskDetails: %v", taskDetails)

		taskFunc(func(tID harmonytask.TaskID, tx *harmonydb.Tx) (bool, error) {
			return t.addTaskToDB(taskDetails.Ts, taskDetails.Deadline, tID, tx)
		})
	}
}

func NewWdPostTask(db *harmonydb.DB, api WDPoStAPI, max int) *WdPostTask {
	return &WdPostTask{
		db:  db,
		api: api,
		max: max,
	}
}

func (t *WdPostTask) addTaskToDB(deadline *dline.Info, taskId harmonytask.TaskID, tx *harmonydb.Tx) (bool, error) {

	_, err := tx.Exec(
		`INSERT INTO wdpost_tasks (
                         task_id,
                          sp_id,
                          proving_period_start,
                          deadline_index,
                          partition_index,
                          
                        ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10 , $11, $12, $13, $14)`,
		taskId,
		spID,
		deadline.PeriodStart,
		deadline.Index,
		partID,
	)
	if err != nil {
		return false, err
	}

	return true, nil
}

var _ harmonytask.TaskInterface = &WdPostTask{}