From 662b14fffb65811c4ea94e65b067e1bcc1350f04 Mon Sep 17 00:00:00 2001
From: Lea Anthony <lea.anthony@gmail.com>
Date: Fri, 30 Oct 2020 15:06:25 +1100
Subject: [PATCH] Initial generation of typescript declarations

---
 .../internal/backendjs/package.d.template     | 15 +++++++
 .../build/internal/backendjs/packages.go      | 42 +++++++++++++++----
 .../build/internal/backendjs/structs.go       | 33 +++++++++++++++
 3 files changed, 82 insertions(+), 8 deletions(-)
 create mode 100644 v2/pkg/commands/build/internal/backendjs/package.d.template

diff --git a/v2/pkg/commands/build/internal/backendjs/package.d.template b/v2/pkg/commands/build/internal/backendjs/package.d.template
new file mode 100644
index 000000000..0fb962224
--- /dev/null
+++ b/v2/pkg/commands/build/internal/backendjs/package.d.template
@@ -0,0 +1,15 @@
+// Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
+// This file is automatically generated. DO NOT EDIT
+
+{{range .Comments}}// {{.}}{{end}}
+{{range .Methods}}
+/**{{if .Comments }}
+{{range .Comments}}  * {{ . }}{{end}}
+  *{{end}}
+  * @function {{.Name}}
+{{range .Inputs}}  * @param {{"{"}}{{.JSType}}{{"}"}} {{.Name}}
+{{end}}  *
+  * @returns {Promise} 
+  */
+export function {{.Name}}({{.InputsAsTSText}}): Promise<{{.OutputsAsTSText}}>;
+{{end}}
\ No newline at end of file
diff --git a/v2/pkg/commands/build/internal/backendjs/packages.go b/v2/pkg/commands/build/internal/backendjs/packages.go
index 1605a97f4..272722aea 100644
--- a/v2/pkg/commands/build/internal/backendjs/packages.go
+++ b/v2/pkg/commands/build/internal/backendjs/packages.go
@@ -102,8 +102,8 @@ func generateIndexJS(packages []*Package) error {
 	templateFile := fs.RelativePath("./index.template")
 
 	// Load template
-	templateData := fs.MustLoadString(templateFile)
-	packagesTemplate, err := template.New("index").Parse(templateData)
+	javascriptTemplateData := fs.MustLoadString(templateFile)
+	packagesTemplate, err := template.New("index").Parse(javascriptTemplateData)
 	if err != nil {
 		return errors.Wrap(err, "Error creating template")
 	}
@@ -132,11 +132,21 @@ func generateIndexJS(packages []*Package) error {
 func generatePackageFiles(packages []*Package) error {
 
 	// Get path to local file
-	templateFile := fs.RelativePath("./package.template")
+	javascriptTemplateFile := fs.RelativePath("./package.template")
 
-	// Load template
-	templateData := fs.MustLoadString(templateFile)
-	packagesTemplate, err := template.New("package").Parse(templateData)
+	// Load javascript template
+	javascriptTemplateData := fs.MustLoadString(javascriptTemplateFile)
+	javascriptTemplate, err := template.New("javascript").Parse(javascriptTemplateData)
+	if err != nil {
+		return errors.Wrap(err, "Error creating template")
+	}
+
+	// Get path to local file
+	typescriptTemplateFile := fs.RelativePath("./package.d.template")
+
+	// Load typescript template
+	typescriptTemplateData := fs.MustLoadString(typescriptTemplateFile)
+	typescriptTemplate, err := template.New("typescript").Parse(typescriptTemplateData)
 	if err != nil {
 		return errors.Wrap(err, "Error creating template")
 	}
@@ -153,17 +163,33 @@ func generatePackageFiles(packages []*Package) error {
 		// Make the dir but ignore if it already exists
 		fs.Mkdir(packageDir)
 
-		// Execute template
+		// Execute javascript template
 		var buffer bytes.Buffer
-		err = packagesTemplate.Execute(&buffer, thisPackage)
+		err = javascriptTemplate.Execute(&buffer, thisPackage)
 		if err != nil {
 			return errors.Wrap(err, "Error generating code")
 		}
 
+		// Save javascript file
 		err = ioutil.WriteFile(filepath.Join(packageDir, "index.js"), buffer.Bytes(), 0755)
 		if err != nil {
 			return errors.Wrap(err, "Error writing backend package file")
 		}
+
+		// Clear buffer
+		buffer.Reset()
+
+		// Execute typescript template
+		err = typescriptTemplate.Execute(&buffer, thisPackage)
+		if err != nil {
+			return errors.Wrap(err, "Error generating code")
+		}
+
+		// Save typescript file
+		err = ioutil.WriteFile(filepath.Join(packageDir, "index.d.ts"), buffer.Bytes(), 0755)
+		if err != nil {
+			return errors.Wrap(err, "Error writing backend package file")
+		}
 	}
 
 	return nil
diff --git a/v2/pkg/commands/build/internal/backendjs/structs.go b/v2/pkg/commands/build/internal/backendjs/structs.go
index a4366f98b..a670143a9 100644
--- a/v2/pkg/commands/build/internal/backendjs/structs.go
+++ b/v2/pkg/commands/build/internal/backendjs/structs.go
@@ -1,6 +1,7 @@
 package backendjs
 
 import (
+	"fmt"
 	"reflect"
 	"strings"
 )
@@ -37,6 +38,38 @@ func (m *Method) InputsAsJSText() string {
 	return strings.Join(inputs, ", ")
 }
 
+// InputsAsTSText generates a string with the method inputs
+// formatted in a way acceptable to Typescript
+func (m *Method) InputsAsTSText() string {
+	var inputs []string
+
+	for _, input := range m.Inputs {
+		inputText := fmt.Sprintf("%s: %s", input.Name, goTypeToJS(input.Type))
+		inputs = append(inputs, inputText)
+	}
+
+	return strings.Join(inputs, ", ")
+}
+
+// OutputsAsTSText generates a string with the method inputs
+// formatted in a way acceptable to Javascript
+func (m *Method) OutputsAsTSText() string {
+
+	if len(m.Outputs) != 2 {
+		return "any"
+	}
+
+	jsType := goTypeToJS(m.Outputs[1].Type)
+	switch jsType {
+	case JsArray:
+		return "Array<any>"
+	case JsObject:
+		return "any"
+	default:
+		return string(jsType)
+	}
+}
+
 // func generateStructFile() {
 // 	// Create string buffer
 // 	var result bytes.Buffer