package models

import (

"database/sql"

"time"

"github.com/go-gorp/gorp"

)

// BlocksModel groups operations on Blocks.

type BlocksModel struct{}

// Block is a block.

type Block struct {

Height int `db:"height" json:"height"` // pk

Hash string `db:"hash" json:"hash"`

Timestamp int64 `db:"timestamp" json:"timestamp"`

TimestampHuman time.Time `db:"-" json:"timestamp_human"`

Version int32 `db:"version" json:"version"`

Producer string `db:"producer" json:"producer"`

MerkleRoot string `db:"merkle_root" json:"merkle_root"`

Parent string `db:"parent" json:"parent"`

TxCount int `db:"tx_count" json:"tx_count"`

}

// PostGet is the hook after SELECT query.

func (b *Block) PostGet(s gorp.SqlExecutor) error {

b.TimestampHuman = time.Unix(0, b.Timestamp)

return nil

}

// GetBlockList get a list of blocks with height in [from, to).

func (m *BlocksModel) GetBlockList(since, page, size int) (blocks []*Block, pagination *Pagination, err error) {

var (

querySQL = `

SELECT

height,

hash,

timestamp,

version,

producer,

merkle_root,

parent,

tx_count

FROM

indexed_blocks

`

countSQL = buildCountSQL(querySQL)

conds []string

args []interface{}

)

pagination = NewPagination(page, size)

if since > 0 {

conds = append(conds, "height < ?")

args = append(args, since)

}

querySQL, countSQL = buildSQLWithConds(querySQL, countSQL, conds)

count, err := chaindb.SelectInt(countSQL, args...)

if err != nil {

return nil, pagination, err

}

pagination.SetTotal(int(count))

blocks = make([]*Block, 0)

if pagination.Offset() > pagination.Total {

return blocks, pagination, nil

}

querySQL += " ORDER BY height DESC"

querySQL += " LIMIT ? OFFSET ?"

args = append(args, pagination.Limit(), pagination.Offset())

_, err = chaindb.Select(&blocks, querySQL, args...)

return blocks, pagination, err

}

// GetBlockByHeight get a block by its height.

func (m *BlocksModel) GetBlockByHeight(height int) (block *Block, err error) {

block = &Block{}

query := `SELECT height, hash, timestamp, version, producer, merkle_root, parent, tx_count

FROM indexed_blocks WHERE height = ?`

err = chaindb.SelectOne(block, query, height)

if err == sql.ErrNoRows {

return nil, nil

}

return block, err

}

// GetBlockByHash get a block by its hash.

func (m *BlocksModel) GetBlockByHash(hash string) (block *Block, err error) {

block = &Block{}

query := `SELECT height, hash, timestamp, version, producer, merkle_root, parent, tx_count

FROM indexed_blocks WHERE hash = ?`

err = chaindb.SelectOne(block, query, hash)

if err == sql.ErrNoRows {

return nil, nil

}

return block, err

}