package orm

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"time"

	"github.com/scroll-tech/go-ethereum/common"
	"github.com/scroll-tech/go-ethereum/log"
	"gorm.io/gorm"

	"scroll-tech/common/types"
	"scroll-tech/common/types/message"
	"scroll-tech/common/utils"
)

const defaultBatchHeaderVersion = 0

// Batch represents a batch of chunks.
type Batch struct {
	db *gorm.DB `gorm:"column:-"`

	// batch
	Index           uint64 `json:"index" gorm:"column:index"`
	Hash            string `json:"hash" gorm:"column:hash"`
	StartChunkIndex uint64 `json:"start_chunk_index" gorm:"column:start_chunk_index"`
	StartChunkHash  string `json:"start_chunk_hash" gorm:"column:start_chunk_hash"`
	EndChunkIndex   uint64 `json:"end_chunk_index" gorm:"column:end_chunk_index"`
	EndChunkHash    string `json:"end_chunk_hash" gorm:"column:end_chunk_hash"`
	StateRoot       string `json:"state_root" gorm:"column:state_root"`
	WithdrawRoot    string `json:"withdraw_root" gorm:"column:withdraw_root"`
	ParentBatchHash string `json:"parent_batch_hash" gorm:"column:parent_batch_hash"`
	BatchHeader     []byte `json:"batch_header" gorm:"column:batch_header"`

	// proof
	ChunkProofsStatus int16      `json:"chunk_proofs_status" gorm:"column:chunk_proofs_status;default:1"`
	ProvingStatus     int16      `json:"proving_status" gorm:"column:proving_status;default:1"`
	Proof             []byte     `json:"proof" gorm:"column:proof;default:NULL"`
	ProverAssignedAt  *time.Time `json:"prover_assigned_at" gorm:"column:prover_assigned_at;default:NULL"`
	ProvedAt          *time.Time `json:"proved_at" gorm:"column:proved_at;default:NULL"`
	ProofTimeSec      int32      `json:"proof_time_sec" gorm:"column:proof_time_sec;default:NULL"`
	TotalAttempts     int16      `json:"total_attempts" gorm:"column:total_attempts;default:0"`
	ActiveAttempts    int16      `json:"active_attempts" gorm:"column:active_attempts;default:0"`

	// rollup
	RollupStatus   int16      `json:"rollup_status" gorm:"column:rollup_status;default:1"`
	CommitTxHash   string     `json:"commit_tx_hash" gorm:"column:commit_tx_hash;default:NULL"`
	CommittedAt    *time.Time `json:"committed_at" gorm:"column:committed_at;default:NULL"`
	FinalizeTxHash string     `json:"finalize_tx_hash" gorm:"column:finalize_tx_hash;default:NULL"`
	FinalizedAt    *time.Time `json:"finalized_at" gorm:"column:finalized_at;default:NULL"`

	// gas oracle
	OracleStatus int16  `json:"oracle_status" gorm:"column:oracle_status;default:1"`
	OracleTxHash string `json:"oracle_tx_hash" gorm:"column:oracle_tx_hash;default:NULL"`

	// metadata
	CreatedAt time.Time      `json:"created_at" gorm:"column:created_at"`
	UpdatedAt time.Time      `json:"updated_at" gorm:"column:updated_at"`
	DeletedAt gorm.DeletedAt `json:"deleted_at" gorm:"column:deleted_at;default:NULL"`
}

// NewBatch creates a new Batch database instance.
func NewBatch(db *gorm.DB) *Batch {
	return &Batch{db: db}
}

// TableName returns the table name for the Batch model.
func (*Batch) TableName() string {
	return "batch"
}

// GetUnassignedBatch retrieves unassigned batch based on the specified limit.
// The returned batch are sorted in ascending order by their index.
func (o *Batch) GetUnassignedBatch(ctx context.Context, maxActiveAttempts, maxTotalAttempts uint8) (*Batch, error) {
	db := o.db.WithContext(ctx)
	db = db.Where("proving_status = ?", int(types.ProvingTaskUnassigned))
	db = db.Where("total_attempts < ?", maxTotalAttempts)
	db = db.Where("active_attempts < ?", maxActiveAttempts)
	db = db.Where("chunk_proofs_status = ?", int(types.ChunkProofsStatusReady))

	var batch Batch
	err := db.First(&batch).Error
	if err != nil && errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, nil
	}

	if err != nil {
		return nil, fmt.Errorf("Batch.GetUnassignedBatches error: %w", err)
	}
	return &batch, nil
}

// GetAssignedBatch retrieves assigned batch based on the specified limit.
// The returned batch are sorted in ascending order by their index.
func (o *Batch) GetAssignedBatch(ctx context.Context, maxActiveAttempts, maxTotalAttempts uint8) (*Batch, error) {
	db := o.db.WithContext(ctx)
	db = db.Where("proving_status = ?", int(types.ProvingTaskAssigned))
	db = db.Where("total_attempts < ?", maxTotalAttempts)
	db = db.Where("active_attempts < ?", maxActiveAttempts)
	db = db.Where("chunk_proofs_status = ?", int(types.ChunkProofsStatusReady))

	var batch Batch
	err := db.First(&batch).Error
	if err != nil && errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, nil
	}

	if err != nil {
		return nil, fmt.Errorf("Batch.GetAssignedBatches error: %w", err)
	}
	return &batch, nil
}

// GetUnassignedAndChunksUnreadyBatches get the batches which is unassigned and chunks is not ready
func (o *Batch) GetUnassignedAndChunksUnreadyBatches(ctx context.Context, offset, limit int) ([]*Batch, error) {
	if offset < 0 || limit < 0 {
		return nil, errors.New("limit and offset must not be smaller than 0")
	}

	db := o.db.WithContext(ctx)
	db = db.Where("proving_status = ?", types.ProvingTaskUnassigned)
	db = db.Where("chunk_proofs_status = ?", types.ChunkProofsStatusPending)
	db = db.Order("index ASC")
	db = db.Offset(offset)
	db = db.Limit(limit)

	var batches []*Batch
	if err := db.Find(&batches).Error; err != nil {
		return nil, fmt.Errorf("Batch.GetUnassignedAndChunksUnreadyBatches error: %w", err)
	}
	return batches, nil
}

// GetAssignedBatches retrieves all batches whose proving_status is either types.ProvingTaskAssigned.
func (o *Batch) GetAssignedBatches(ctx context.Context) ([]*Batch, error) {
	db := o.db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Where("proving_status = ?", int(types.ProvingTaskAssigned))

	var assignedBatches []*Batch
	if err := db.Find(&assignedBatches).Error; err != nil {
		return nil, fmt.Errorf("Batch.GetAssignedBatches error: %w", err)
	}
	return assignedBatches, nil
}

// GetProvingStatusByHash retrieves the proving status of a batch given its hash.
func (o *Batch) GetProvingStatusByHash(ctx context.Context, hash string) (types.ProvingStatus, error) {
	db := o.db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Select("proving_status")
	db = db.Where("hash = ?", hash)

	var batch Batch
	if err := db.Find(&batch).Error; err != nil {
		return types.ProvingStatusUndefined, fmt.Errorf("Batch.GetProvingStatusByHash error: %w, batch hash: %v", err, hash)
	}
	return types.ProvingStatus(batch.ProvingStatus), nil
}

// GetLatestBatch retrieves the latest batch from the database.
func (o *Batch) GetLatestBatch(ctx context.Context) (*Batch, error) {
	db := o.db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Order("index desc")

	var latestBatch Batch
	if err := db.First(&latestBatch).Error; err != nil {
		return nil, fmt.Errorf("Batch.GetLatestBatch error: %w", err)
	}
	return &latestBatch, nil
}

// GetAttemptsByHash get batch attempts by hash. Used by unit test
func (o *Batch) GetAttemptsByHash(ctx context.Context, hash string) (int16, int16, error) {
	db := o.db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Where("hash = ?", hash)
	var batch Batch
	if err := db.Find(&batch).Error; err != nil {
		return 0, 0, fmt.Errorf("Batch.GetAttemptsByHash error: %w, batch hash: %v", err, hash)
	}
	return batch.ActiveAttempts, batch.TotalAttempts, nil
}

// InsertBatch inserts a new batch into the database.
// for unit test
func (o *Batch) InsertBatch(ctx context.Context, startChunkIndex, endChunkIndex uint64, startChunkHash, endChunkHash string, chunks []*types.Chunk, dbTX ...*gorm.DB) (*Batch, error) {
	if len(chunks) == 0 {
		return nil, errors.New("invalid args")
	}

	parentBatch, err := o.GetLatestBatch(ctx)
	if err != nil && !errors.Is(errors.Unwrap(err), gorm.ErrRecordNotFound) {
		log.Error("failed to get the latest batch", "err", err)
		return nil, err
	}

	var batchIndex uint64
	var parentBatchHash common.Hash
	var totalL1MessagePoppedBefore uint64
	var version uint8 = defaultBatchHeaderVersion

	// if parentBatch==nil then err==gorm.ErrRecordNotFound, which means there's
	// not batch record in the db, we then use default empty values for the creating batch;
	// if parentBatch!=nil then err=nil, then we fill the parentBatch-related data into the creating batch
	if parentBatch != nil {
		batchIndex = parentBatch.Index + 1
		parentBatchHash = common.HexToHash(parentBatch.Hash)

		var parentBatchHeader *types.BatchHeader
		parentBatchHeader, err = types.DecodeBatchHeader(parentBatch.BatchHeader)
		if err != nil {
			log.Error("failed to decode parent batch header", "index", parentBatch.Index, "hash", parentBatch.Hash, "err", err)
			return nil, err
		}

		totalL1MessagePoppedBefore = parentBatchHeader.TotalL1MessagePopped()
		version = parentBatchHeader.Version()
	}

	batchHeader, err := types.NewBatchHeader(version, batchIndex, totalL1MessagePoppedBefore, parentBatchHash, chunks)
	if err != nil {
		log.Error("failed to create batch header",
			"index", batchIndex, "total l1 message popped before", totalL1MessagePoppedBefore,
			"parent hash", parentBatchHash, "number of chunks", len(chunks), "err", err)
		return nil, err
	}

	numChunks := len(chunks)
	lastChunkBlockNum := len(chunks[numChunks-1].Blocks)

	newBatch := Batch{
		Index:             batchIndex,
		Hash:              batchHeader.Hash().Hex(),
		StartChunkHash:    startChunkHash,
		StartChunkIndex:   startChunkIndex,
		EndChunkHash:      endChunkHash,
		EndChunkIndex:     endChunkIndex,
		StateRoot:         chunks[numChunks-1].Blocks[lastChunkBlockNum-1].Header.Root.Hex(),
		WithdrawRoot:      chunks[numChunks-1].Blocks[lastChunkBlockNum-1].WithdrawRoot.Hex(),
		ParentBatchHash:   parentBatchHash.Hex(),
		BatchHeader:       batchHeader.Encode(),
		ChunkProofsStatus: int16(types.ChunkProofsStatusPending),
		ProvingStatus:     int16(types.ProvingTaskUnassigned),
		TotalAttempts:     0,
		ActiveAttempts:    0,
		RollupStatus:      int16(types.RollupPending),
		OracleStatus:      int16(types.GasOraclePending),
	}

	db := o.db
	if len(dbTX) > 0 && dbTX[0] != nil {
		db = dbTX[0]
	}
	db.WithContext(ctx)
	db = db.Model(&Batch{})

	if err := db.Create(&newBatch).Error; err != nil {
		log.Error("failed to insert batch", "batch", newBatch, "err", err)
		return nil, fmt.Errorf("Batch.InsertBatch error: %w", err)
	}
	return &newBatch, nil
}

// UpdateChunkProofsStatusByBatchHash updates the status of chunk_proofs_status field for a given batch hash.
// The function will set the chunk_proofs_status to the status provided.
func (o *Batch) UpdateChunkProofsStatusByBatchHash(ctx context.Context, batchHash string, status types.ChunkProofsStatus) error {
	db := o.db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Where("hash = ?", batchHash)

	if err := db.Update("chunk_proofs_status", status).Error; err != nil {
		return fmt.Errorf("Batch.UpdateChunkProofsStatusByBatchHash error: %w, batch hash: %v, status: %v", err, batchHash, status.String())
	}
	return nil
}

// UpdateProvingStatusFailed updates the proving status failed of a batch.
func (o *Batch) UpdateProvingStatusFailed(ctx context.Context, hash string, maxAttempts uint8, dbTX ...*gorm.DB) error {
	db := o.db
	if len(dbTX) > 0 && dbTX[0] != nil {
		db = dbTX[0]
	}
	db = db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Where("hash", hash)
	db = db.Where("total_attempts >= ?", maxAttempts)
	db = db.Where("proving_status != ?", int(types.ProverProofValid))
	if err := db.Update("proving_status", int(types.ProvingTaskFailed)).Error; err != nil {
		return fmt.Errorf("Batch.UpdateProvingStatus error: %w, batch hash: %v, status: %v", err, hash, types.ProvingTaskFailed.String())
	}
	return nil
}

// UpdateProofAndProvingStatusByHash updates the batch proof and proving status by hash.
func (o *Batch) UpdateProofAndProvingStatusByHash(ctx context.Context, hash string, proof *message.BatchProof, provingStatus types.ProvingStatus, proofTimeSec uint64, dbTX ...*gorm.DB) error {
	db := o.db
	if len(dbTX) > 0 && dbTX[0] != nil {
		db = dbTX[0]
	}
	proofBytes, err := json.Marshal(proof)
	if err != nil {
		return err
	}

	updateFields := make(map[string]interface{})
	updateFields["proof"] = proofBytes
	updateFields["proving_status"] = provingStatus
	updateFields["proof_time_sec"] = proofTimeSec
	updateFields["proved_at"] = utils.NowUTC()

	db = db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Where("hash", hash)

	if err := db.Updates(updateFields).Error; err != nil {
		return fmt.Errorf("Batch.UpdateProofByHash error: %w, batch hash: %v", err, hash)
	}
	return nil
}

// UpdateBatchAttempts atomically increments the attempts count for the earliest available batch that meets the conditions.
func (o *Batch) UpdateBatchAttempts(ctx context.Context, index uint64, curActiveAttempts, curTotalAttempts int16) (int64, error) {
	db := o.db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Where("index = ?", index)
	db = db.Where("active_attempts = ?", curActiveAttempts)
	db = db.Where("total_attempts = ?", curTotalAttempts)
	result := db.Updates(map[string]interface{}{
		"proving_status":  types.ProvingTaskAssigned,
		"total_attempts":  gorm.Expr("total_attempts + 1"),
		"active_attempts": gorm.Expr("active_attempts + 1"),
	})

	if result.Error != nil {
		return 0, fmt.Errorf("failed to update batch, err:%w", result.Error)
	}
	return result.RowsAffected, nil
}

// DecreaseActiveAttemptsByHash decrements the active_attempts of a batch given its hash.
func (o *Batch) DecreaseActiveAttemptsByHash(ctx context.Context, batchHash string, dbTX ...*gorm.DB) error {
	db := o.db
	if len(dbTX) > 0 && dbTX[0] != nil {
		db = dbTX[0]
	}
	db = db.WithContext(ctx)
	db = db.Model(&Batch{})
	db = db.Where("hash = ?", batchHash)
	db = db.Where("proving_status != ?", int(types.ProvingTaskVerified))
	db = db.Where("active_attempts > ?", 0)
	result := db.UpdateColumn("active_attempts", gorm.Expr("active_attempts - 1"))
	if result.Error != nil {
		return fmt.Errorf("Chunk.DecreaseActiveAttemptsByHash error: %w, batch hash: %v", result.Error, batchHash)
	}
	if result.RowsAffected == 0 {
		log.Warn("No rows were affected in DecreaseActiveAttemptsByHash", "batch hash", batchHash)
	}
	return nil
}