package orm

import (
	"context"
	"errors"
	"fmt"
	"time"

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

	"scroll-tech/common/types"
)

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"`

	// 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"
}

// 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
}

// InsertBatch inserts a new batch into the database.
// for init data
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),
		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
}