TMP: codetables

pkg/codegen/modelgenerate/generate_codetable_type.go

@@ -0,0 +1,111 @@
+package modelgenerate
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/schema"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
+)
+
+func GenerateCodetableType(table schema.Table) *ast.GenDecl {
+	return &ast.GenDecl{
+		Tok:   token.TYPE,
+		Specs: []ast.Spec{&ast.TypeSpec{Name: &ast.Ident{Name: table.GoTypeName}, Type: &ast.Ident{Name: "int"}}},
+	}
+}
+
+func GenerateCodetableEnum(table schema.Table, vals []string) *ast.GenDecl {
+	getConstName := func(s string) string {
+		return table.GoTypeName + textutils.KebabToPascal(s)
+	}
+
+	constSpecs := []ast.Spec{}
+	for i, val := range vals {
+		spec := &ast.ValueSpec{
+			Names: []*ast.Ident{{Name: getConstName(val)}},
+		}
+		// Only the first one needs `iota`
+		if i == 0 {
+			spec.Type = &ast.Ident{Name: table.GoTypeName}
+			spec.Values = []ast.Expr{&ast.BinaryExpr{
+				X:  &ast.Ident{Name: "iota"},
+				Op: token.ADD,
+				Y:  &ast.BasicLit{Kind: token.INT, Value: "1"},
+			}}
+		}
+		constSpecs = append(constSpecs, spec)
+	}
+
+	return &ast.GenDecl{Tok: token.CONST, Specs: constSpecs}
+}
+
+// GenerateCodetableStringerFunc implements the `Stringer` interface by defining a `String() string` function.
+func GenerateCodetableStringerFunc(table schema.Table, vals []string) *ast.FuncDecl {
+	objIdent := ast.NewIdent(table.VarName)
+	return &ast.FuncDecl{
+		Recv: &ast.FieldList{List: []*ast.Field{{Names: []*ast.Ident{objIdent}, Type: &ast.Ident{Name: table.GoTypeName}}}},
+		Name: &ast.Ident{Name: "String"},
+		Type: &ast.FuncType{Params: &ast.FieldList{}, Results: &ast.FieldList{List: []*ast.Field{{Type: &ast.Ident{Name: "string"}}}}},
+		Body: &ast.BlockStmt{
+			List: []ast.Stmt{
+				// names := []string{ ... }
+				&ast.AssignStmt{
+					Lhs: []ast.Expr{&ast.Ident{Name: "names"}},
+					Tok: token.DEFINE,
+					Rhs: []ast.Expr{
+						&ast.CompositeLit{
+							Type: &ast.ArrayType{Elt: &ast.Ident{Name: "string"}},
+							Elts: func() []ast.Expr {
+								ret := []ast.Expr{
+									&ast.BasicLit{Kind: token.STRING, Value: `""`},
+								}
+								for _, val := range vals {
+									ret = append(ret, &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", val)})
+								}
+								return ret
+							}(),
+						},
+					},
+				},
+
+				// if int(c) < 1 || int(c) >= len(names) { return "invalid" }
+				&ast.IfStmt{
+					Cond: &ast.BinaryExpr{
+						X: &ast.BinaryExpr{
+							X:  &ast.CallExpr{Fun: &ast.Ident{Name: "int"}, Args: []ast.Expr{objIdent}},
+							Op: token.LSS,
+							Y:  &ast.BasicLit{Kind: token.INT, Value: "1"},
+						},
+						Op: token.LOR,
+						Y: &ast.BinaryExpr{
+							X:  &ast.CallExpr{Fun: &ast.Ident{Name: "int"}, Args: []ast.Expr{objIdent}},
+							Op: token.GEQ,
+							Y:  &ast.CallExpr{Fun: &ast.Ident{Name: "len"}, Args: []ast.Expr{&ast.Ident{Name: "names"}}},
+						},
+					},
+					Body: &ast.BlockStmt{
+						List: []ast.Stmt{
+							&ast.ReturnStmt{Results: []ast.Expr{
+								&ast.CallExpr{Fun: &ast.SelectorExpr{X: ast.NewIdent("fmt"), Sel: ast.NewIdent("Sprintf")}, Args: []ast.Expr{
+									&ast.BasicLit{Kind: token.STRING, Value: `"<%d=invalid>"`},
+									objIdent,
+								}},
+							}},
+						},
+					},
+				},
+				// return names[c]
+				&ast.ReturnStmt{
+					Results: []ast.Expr{
+						&ast.IndexExpr{
+							X:     &ast.Ident{Name: "names"},
+							Index: objIdent,
+						},
+					},
+				},
+			},
+		},
+	}
+}