feat: split into code for buffer and vm

internals/vm/vm.go

@@ -0,0 +1,86 @@
+package vm
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	. "godb/internals/buffer"
+)
+
+type MetaCommandResults int
+
+const (
+	MetaCommandSuccess MetaCommandResults = iota
+	MetaCommandUnrecognised
+)
+
+type PrepareResults int
+
+const (
+	PrepareSuccess PrepareResults = iota
+	PrepareUnrecognised
+	PrepareSyntaxError
+)
+
+type statementType int
+
+const (
+	StatementSelect statementType = iota
+	StatementInsert
+)
+
+type row struct {
+	id       uint
+	username string
+	email    string
+}
+
+type Statement struct {
+	stype statementType
+	row   row
+}
+
+func NewStatement() *Statement {
+	return &Statement{0, row{0, "", ""}}
+}
+
+func DoMetaCommands(inputBuffer *InputBuffer) MetaCommandResults {
+	metacommand := MetaCommandUnrecognised
+	if inputBuffer.Buffer == ".exit" {
+		fmt.Println("bye!")
+		os.Exit(0)
+	} else {
+		metacommand = MetaCommandUnrecognised
+	}
+	return metacommand
+}
+
+func (statement *Statement) PrepareStatements(inputBuffer *InputBuffer) PrepareResults {
+	if strings.HasPrefix(inputBuffer.Buffer, "insert") {
+		argsAssigned, err := fmt.Sscanf(inputBuffer.Buffer, "insert %d %s %s", &statement.row.id, &statement.row.username, &statement.row.email)
+		if err != nil {
+			fmt.Println("error parsing insert statement")
+			fmt.Println(err.Error())
+		}
+		if argsAssigned > 3 {
+			return PrepareSyntaxError
+		}
+		statement.stype = StatementInsert
+		return PrepareSuccess
+	}
+	if strings.HasPrefix(inputBuffer.Buffer, "select") {
+		statement.stype = StatementSelect
+		return PrepareSuccess
+	}
+	return PrepareUnrecognised
+}
+
+func (statement *Statement) ExecuteStatement() {
+	switch statement.stype {
+	case StatementInsert:
+		fmt.Println("This is where the logic of insert statement should go")
+	case StatementSelect:
+		fmt.Println("This is where the logic of select statement should go")
+	}
+}