From 1a431dd26c02dbb611c20395b236928185798e1d Mon Sep 17 00:00:00 2001
From: Shreyas Goenka <shreyas.goenka@databricks.com>
Date: Mon, 15 May 2023 11:25:01 +0200
Subject: [PATCH] wip

---
 cmd/init/Untitled-1.json | 21 ++++++++++++
 cmd/init/file_tree.go    | 74 ++++++++++++++++++++++++++++++++++++++++
 cmd/init/helpers.go      | 31 +++++++++++++++++
 cmd/init/init.go         | 45 ++++++++++++++++++++++++
 main.go                  |  1 +
 5 files changed, 172 insertions(+)
 create mode 100644 cmd/init/Untitled-1.json
 create mode 100644 cmd/init/file_tree.go
 create mode 100644 cmd/init/helpers.go
 create mode 100644 cmd/init/init.go

diff --git a/cmd/init/Untitled-1.json b/cmd/init/Untitled-1.json
new file mode 100644
index 00000000..35c17247
--- /dev/null
+++ b/cmd/init/Untitled-1.json
@@ -0,0 +1,21 @@
+{
+    "foo": {
+        "type": "string",
+        "default": "abc",
+        "validation": ["regex ^[abcd]*$"]
+    },
+    "bar": {
+        "type": "integer",
+        "default": 123,
+        "validation": ["greaterThan 5", "lessThan 10"]
+    },
+    "isAws": {
+        "type": "boolean",
+        "default": true
+    },
+    "project_name": {
+        "type": "string",
+        "default": "my_project",
+        "validation": ["startsWith my_"]
+    }
+}
diff --git a/cmd/init/file_tree.go b/cmd/init/file_tree.go
new file mode 100644
index 00000000..1f8b8791
--- /dev/null
+++ b/cmd/init/file_tree.go
@@ -0,0 +1,74 @@
+package init
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+)
+
+// TODO: cleanup if template initialization fails
+// TODO: need robust way to clean up half generated files
+// TODO: define default files
+// TODO: self reference for 
+
+func walkFileTree(config map[string]interface{}, templatePath string, instancePath string) error {
+	enteries, err := os.ReadDir(templatePath)
+	if err != nil {
+		return err
+	}
+	for _, entry := range enteries {
+		if entry.Name() == SchemaFileName {
+			continue
+		}
+		fileName := entry.Name()
+		tmpl, err := template.New("filename").Parse(fileName)
+		if err != nil {
+			return err
+		}
+		result := strings.Builder{}
+		err = tmpl.Execute(&result, config)
+		if err != nil {
+			return err
+		}
+		resolvedFileName := result.String()
+		fmt.Println(resolvedFileName)
+		if entry.IsDir() {
+			err := os.Mkdir(resolvedFileName, os.ModePerm)
+			if err != nil {
+				return err
+			}
+			err = walkFileTree(config, filepath.Join(templatePath, fileName), filepath.Join(instancePath, resolvedFileName))
+			if err != nil {
+				return err
+			}
+		} else {
+			f, err := os.Create(filepath.Join(instancePath, resolvedFileName))
+			if err != nil {
+				return err
+			}
+			b, err := os.ReadFile(filepath.Join(templatePath, fileName))
+			if err != nil {
+				return err
+			}
+			// TODO: Might be able to use ParseFiles or ParseFS. Might be more suited
+			contentTmpl, err := template.New("content").Funcs(HelperFuncs).Parse(string(b))
+			if err != nil {
+				return err
+			}
+			err = contentTmpl.Execute(f, config)
+
+			// Make this assertion more robust
+			if err != nil && strings.Contains(err.Error(), ErrSkipThisFile.Error()) {
+				err := os.Remove(filepath.Join(instancePath, resolvedFileName))
+				if err != nil {
+					return err
+				}
+			} else if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
diff --git a/cmd/init/helpers.go b/cmd/init/helpers.go
new file mode 100644
index 00000000..b1df69fb
--- /dev/null
+++ b/cmd/init/helpers.go
@@ -0,0 +1,31 @@
+package init
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"text/template"
+)
+
+var ErrSkipThisFile = errors.New("skip generating this file")
+
+var HelperFuncs = template.FuncMap{
+	"skipThisFile": func() error {
+		panic(ErrSkipThisFile)
+	},
+	"eqString": func(a string, b string) bool {
+		return a == b
+	},
+	"eqNumber": func(a float64, b int) bool {
+		return int(a) == b
+	},
+	"validationError": func(message string) error {
+		panic(fmt.Errorf(message))
+	},
+	"assertStartsWith": func(s string, substr string) error {
+		if !strings.HasPrefix(s, substr) {
+			panic(fmt.Errorf("%s does not start with %s.", s, substr))
+		}
+		return nil
+	},
+}
diff --git a/cmd/init/init.go b/cmd/init/init.go
new file mode 100644
index 00000000..fed7321b
--- /dev/null
+++ b/cmd/init/init.go
@@ -0,0 +1,45 @@
+package init
+
+import (
+	"encoding/json"
+	"os"
+
+	"github.com/databricks/bricks/cmd/root"
+	"github.com/spf13/cobra"
+)
+
+const SchemaFileName = "config.json"
+
+// root template defination at schema.json
+// decide on semantics of defination later
+
+// initCmd represents the fs command
+var initCmd = &cobra.Command{
+	Use:   "init",
+	Short: "Initialize Template",
+	Long:  `Initialize bundle template`,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		var config map[string]interface{}
+		b, err := os.ReadFile(SchemaFileName)
+		if err != nil {
+			return err
+		}
+		err = json.Unmarshal(b, &config)
+		if err != nil {
+			return err
+		}
+		err = walkFileTree(config, ".", ".")
+		if err != nil {
+			err2 := os.RemoveAll("favela")
+			if err2 != nil {
+				return err2
+			}
+			return err
+		}
+		return nil
+	},
+}
+
+func init() {
+	root.RootCmd.AddCommand(initCmd)
+}
diff --git a/main.go b/main.go
index fd5d31f3..1ef34ccc 100644
--- a/main.go
+++ b/main.go
@@ -8,6 +8,7 @@ import (
 	_ "github.com/databricks/bricks/cmd/bundle/debug"
 	_ "github.com/databricks/bricks/cmd/configure"
 	_ "github.com/databricks/bricks/cmd/fs"
+	_ "github.com/databricks/bricks/cmd/init"
 	"github.com/databricks/bricks/cmd/root"
 	_ "github.com/databricks/bricks/cmd/sync"
 	_ "github.com/databricks/bricks/cmd/version"