Package path refactor.

clause.go

@@ -0,0 +1,249 @@
+package jet
+
+import (
+	"bytes"
+	"github.com/google/uuid"
+	"github.com/lib/pq"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type serializeOption int
+
+const (
+	NO_WRAP serializeOption = iota
+)
+
+type clause interface {
+	serialize(statement statementType, out *queryData, options ...serializeOption) error
+}
+
+func contains(options []serializeOption, option serializeOption) bool {
+	for _, opt := range options {
+		if opt == option {
+			return true
+		}
+	}
+
+	return false
+}
+
+type queryData struct {
+	buff bytes.Buffer
+	args []interface{}
+
+	lastChar byte
+	ident    int
+}
+
+type statementType string
+
+const (
+	select_statement statementType = "SELECT"
+	insert_statement statementType = "INSERT"
+	update_statement statementType = "UPDATE"
+	delete_statement statementType = "DELETE"
+	set_statement    statementType = "SET"
+	lock_statement   statementType = "LOCK"
+)
+
+const defaultIdent = 5
+
+func (q *queryData) increaseIdent() {
+	q.ident += defaultIdent
+}
+
+func (q *queryData) decreaseIdent() {
+	if q.ident < defaultIdent {
+		q.ident = 0
+	}
+
+	q.ident -= defaultIdent
+}
+
+func (q *queryData) writeProjections(statement statementType, projections []projection) error {
+	q.increaseIdent()
+	err := serializeProjectionList(statement, projections, q)
+	q.decreaseIdent()
+	return err
+}
+
+func (q *queryData) writeFrom(statement statementType, table ReadableTable) error {
+	q.newLine()
+	q.writeString("FROM")
+
+	q.increaseIdent()
+	err := table.serialize(statement, q)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *queryData) writeWhere(statement statementType, where Expression) error {
+	q.newLine()
+	q.writeString("WHERE")
+
+	q.increaseIdent()
+	err := where.serialize(statement, q, NO_WRAP)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *queryData) 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 *queryData) 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 *queryData) writeHaving(statement statementType, having Expression) error {
+	q.newLine()
+	q.writeString("HAVING")
+
+	q.increaseIdent()
+	err := having.serialize(statement, q, NO_WRAP)
+	q.decreaseIdent()
+
+	return err
+}
+
+func (q *queryData) newLine() {
+	q.write([]byte{'\n'})
+	q.write(bytes.Repeat([]byte{' '}, q.ident))
+}
+
+func (q *queryData) 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 *queryData) writeQuotedString(str string) {
+	q.writeString(`"` + str + `"`)
+}
+
+func (q *queryData) writeString(str string) {
+	q.write([]byte(str))
+}
+
+func (q *queryData) writeIdentifier(name string) {
+	quoteWrap := name != strings.ToLower(name) || strings.Contains(name, ".")
+
+	if quoteWrap {
+		q.writeString(`"` + name + `"`)
+	} else {
+		q.writeString(name)
+	}
+}
+
+func (q *queryData) writeByte(b byte) {
+	q.write([]byte{b})
+}
+
+func (q *queryData) finalize() (string, []interface{}) {
+	return q.buff.String() + ";\n", q.args
+}
+
+func (q *queryData) insertConstantArgument(arg interface{}) {
+	q.writeString(ArgToString(arg))
+}
+
+func (q *queryData) insertPreparedArgument(arg interface{}) {
+	q.args = append(q.args, arg)
+	argPlaceholder := "$" + strconv.Itoa(len(q.args))
+
+	q.writeString(argPlaceholder)
+}
+
+func (q *queryData) reset() {
+	q.buff.Reset()
+	q.args = []interface{}{}
+}
+
+func ArgToString(value interface{}) string {
+	if isNil(value) {
+		return "NULL"
+	}
+
+	switch bindVal := value.(type) {
+	case bool:
+		if bindVal {
+			return "TRUE"
+		} else {
+			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(pq.FormatTimestamp(bindVal)))
+	default:
+		return "[Unknown type]"
+	}
+}
+
+func stringQuote(value string) string {
+	return `'` + strings.Replace(value, "'", "''", -1) + `'`
+}