Package structure refactor.

internal/jet/clause.go

@@ -0,0 +1,270 @@
+package jet
+
+import (
+	"bytes"
+	"github.com/go-jet/jet/internal/utils"
+	"github.com/google/uuid"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type SerializeOption int
+
+const (
+	noWrap SerializeOption = iota
+)
+
+type Clause interface {
+	serialize(statement StatementType, out *SqlBuilder, options ...SerializeOption) error
+}
+
+func Serialize(exp Clause, statementType StatementType, out *SqlBuilder, options ...SerializeOption) error {
+	return exp.serialize(statementType, out, options...)
+}
+
+func contains(options []SerializeOption, option SerializeOption) bool {
+	for _, opt := range options {
+		if opt == option {
+			return true
+		}
+	}
+
+	return false
+}
+
+type SqlBuilder struct {
+	Dialect Dialect
+	Buff    bytes.Buffer
+	Args    []interface{}
+
+	lastChar byte
+	ident    int
+}
+
+func (s *SqlBuilder) DebugSQL() string {
+	return queryStringToDebugString(s.Buff.String(), s.Args, s.Dialect)
+}
+
+type StatementType string
+
+const (
+	SelectStatementType StatementType = "SELECT"
+	InsertStatementType StatementType = "INSERT"
+	UpdateStatementType StatementType = "UPDATE"
+	DeleteStatementType StatementType = "DELETE"
+	SetStatementType    StatementType = "SET"
+	LockStatementType   StatementType = "LOCK"
+)
+
+const defaultIdent = 5
+
+func (q *SqlBuilder) increaseIdent() {
+	q.ident += defaultIdent
+}
+
+func (q *SqlBuilder) decreaseIdent() {
+	if q.ident < defaultIdent {
+		q.ident = 0
+	}
+
+	q.ident -= defaultIdent
+}
+
+func (q *SqlBuilder) writeProjections(statement StatementType, projections []Projection) error {
+	q.increaseIdent()
+	err := SerializeProjectionList(statement, projections, q)
+	q.decreaseIdent()
+	return err
+}
+
+func (q *SqlBuilder) writeFrom(statement StatementType, table ReadableTable) error {
+	q.newLine()
+	q.WriteString("FROM")
+
+	q.increaseIdent()
+	err := table.serialize(statement, q)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *SqlBuilder) writeWhere(statement StatementType, where Expression) error {
+	q.newLine()
+	q.WriteString("WHERE")
+
+	q.increaseIdent()
+	err := where.serialize(statement, q, noWrap)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *SqlBuilder) writeGroupBy(statement StatementType, groupBy []groupByClause) error {
+	q.newLine()
+	q.WriteString("GROUP BY")
+
+	q.increaseIdent()
+	err := serializeGroupByClauseList(statement, groupBy, q)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *SqlBuilder) writeOrderBy(statement StatementType, orderBy []orderByClause) error {
+	q.newLine()
+	q.WriteString("ORDER BY")
+
+	q.increaseIdent()
+	err := serializeOrderByClauseList(statement, orderBy, q)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *SqlBuilder) writeHaving(statement StatementType, having Expression) error {
+	q.newLine()
+	q.WriteString("HAVING")
+
+	q.increaseIdent()
+	err := having.serialize(statement, q, noWrap)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *SqlBuilder) writeReturning(statement StatementType, returning []Projection) error {
+	if len(returning) == 0 {
+		return nil
+	}
+
+	if !q.Dialect.SupportsReturning() {
+		panic("jet: " + q.Dialect.Name() + " dialect does not support RETURNING.")
+	}
+
+	q.newLine()
+	q.WriteString("RETURNING")
+	q.increaseIdent()
+
+	return q.writeProjections(statement, returning)
+}
+
+func (q *SqlBuilder) newLine() {
+	q.write([]byte{'\n'})
+	q.write(bytes.Repeat([]byte{' '}, q.ident))
+}
+
+func (q *SqlBuilder) write(data []byte) {
+	if len(data) == 0 {
+		return
+	}
+
+	if !isPreSeparator(q.lastChar) && !isPostSeparator(data[0]) && q.Buff.Len() > 0 {
+		q.Buff.WriteByte(' ')
+	}
+
+	q.Buff.Write(data)
+	q.lastChar = data[len(data)-1]
+}
+
+func isPreSeparator(b byte) bool {
+	return b == ' ' || b == '.' || b == ',' || b == '(' || b == '\n' || b == ':'
+}
+
+func isPostSeparator(b byte) bool {
+	return b == ' ' || b == '.' || b == ',' || b == ')' || b == '\n' || b == ':'
+}
+
+func (q *SqlBuilder) writeAlias(str string) {
+	aliasQuoteChar := string(q.Dialect.AliasQuoteChar())
+	q.WriteString(aliasQuoteChar + str + aliasQuoteChar)
+}
+
+func (q *SqlBuilder) WriteString(str string) {
+	q.write([]byte(str))
+}
+
+func (q *SqlBuilder) writeIdentifier(name string, alwaysQuote ...bool) {
+	quoteWrap := name != strings.ToLower(name) || strings.ContainsAny(name, ". -")
+
+	if quoteWrap || len(alwaysQuote) > 0 {
+		identQuoteChar := string(q.Dialect.IdentifierQuoteChar())
+		q.WriteString(identQuoteChar + name + identQuoteChar)
+	} else {
+		q.WriteString(name)
+	}
+}
+
+func (q *SqlBuilder) writeByte(b byte) {
+	q.write([]byte{b})
+}
+
+func (q *SqlBuilder) finalize() (string, []interface{}) {
+	return q.Buff.String() + ";\n", q.Args
+}
+
+func (q *SqlBuilder) insertConstantArgument(arg interface{}) {
+	q.WriteString(argToString(arg))
+}
+
+func (q *SqlBuilder) insertParametrizedArgument(arg interface{}) {
+	q.Args = append(q.Args, arg)
+	argPlaceholder := q.Dialect.ArgumentPlaceholder()(len(q.Args))
+
+	q.WriteString(argPlaceholder)
+}
+
+func argToString(value interface{}) string {
+	if utils.IsNil(value) {
+		return "NULL"
+	}
+
+	switch bindVal := value.(type) {
+	case bool:
+		if bindVal {
+			return "TRUE"
+		}
+		return "FALSE"
+	case int8:
+		return strconv.FormatInt(int64(bindVal), 10)
+	case int:
+		return strconv.FormatInt(int64(bindVal), 10)
+	case int16:
+		return strconv.FormatInt(int64(bindVal), 10)
+	case int32:
+		return strconv.FormatInt(int64(bindVal), 10)
+	case int64:
+		return strconv.FormatInt(int64(bindVal), 10)
+
+	case uint8:
+		return strconv.FormatUint(uint64(bindVal), 10)
+	case uint:
+		return strconv.FormatUint(uint64(bindVal), 10)
+	case uint16:
+		return strconv.FormatUint(uint64(bindVal), 10)
+	case uint32:
+		return strconv.FormatUint(uint64(bindVal), 10)
+	case uint64:
+		return strconv.FormatUint(uint64(bindVal), 10)
+
+	case float32:
+		return strconv.FormatFloat(float64(bindVal), 'f', -1, 64)
+	case float64:
+		return strconv.FormatFloat(float64(bindVal), 'f', -1, 64)
+
+	case string:
+		return stringQuote(bindVal)
+	case []byte:
+		return stringQuote(string(bindVal))
+	case uuid.UUID:
+		return stringQuote(bindVal.String())
+	case time.Time:
+		return stringQuote(string(utils.FormatTimestamp(bindVal)))
+	default:
+		return "[Unsupported type]"
+	}
+}
+
+func stringQuote(value string) string {
+	return `'` + strings.Replace(value, "'", "''", -1) + `'`
+}