feat: Parse parameters into JSON schema objects (#5468)

* Parse parameters into JSON schema objects

* Add JSON indent

* Add case checking

* Make param type variable

---------

Co-authored-by: Leonardo Gama <leogama@amazon.com>

schema/schema.py

@@ -2,15 +2,23 @@
 
 
 import importlib
-from typing import Dict, List, Optional, Union
+import json
+from enum import Enum
+from typing import Any, Dict
 
 import click
 
 from samcli.cli.command import _SAM_CLI_COMMAND_PACKAGES
 from samcli.lib.config.samconfig import SamConfig
 
 
-def format_param(param: click.core.Option) -> Dict[str, Union[Optional[str], List[str]]]:
+class SchemaKeys(Enum):
+    SCHEMA_FILE_NAME = "samcli.json"
+    SCHEMA_DRAFT = "http://json-schema.org/draft-04/schema"
+    TITLE = "AWS SAM CLI samconfig schema"
+
+
+def format_param(param: click.core.Option) -> Dict[str, Any]:
     """Format a click Option parameter to a dictionary object.
 
     A parameter object should contain the following information that will be
@@ -22,20 +30,23 @@ def format_param(param: click.core.Option) -> Dict[str, Union[Optional[str], Lis
                        a list of those allowed options
     * default - The default option for that parameter
     """
-    formatted_param: Dict[str, Union[Optional[str], List[str]]] = {"name": param.name, "help": param.help}
+    formatted_param: Dict[str, Any] = {"title": param.name, "description": param.help}
 
     # NOTE: Params do not have explicit "string" type; either "text" or "path".
     #       All choice options are from a set of strings.
-    if param.type.name in ["text", "path", "choice"]:
+    param_type = param.type.name.lower()
+    if param_type in ["text", "path", "choice", "filename", "directory"]:
         formatted_param["type"] = "string"
+    elif param_type == "list":
+        formatted_param["type"] = "array"
     else:
-        formatted_param["type"] = param.type.name
+        formatted_param["type"] = param_type or "string"
 
     if param.default:
-        formatted_param["default"] = str(param.default)
+        formatted_param["default"] = list(param.default) if isinstance(param.default, tuple) else param.default
 
     if param.type.name == "choice" and isinstance(param.type, click.Choice):
-        formatted_param["choices"] = list(param.type.choices)
+        formatted_param["enum"] = list(param.type.choices)
 
     return formatted_param
 
@@ -91,15 +102,34 @@ def generate_schema() -> dict:
     schema: dict = {}
     commands = {}
     params = set()  # NOTE(leogama): Currently unused due to some params having different help values
-    # TODO: Populate schema with relevant attributes
+
+    # Populate schema with relevant attributes
+    schema["$schema"] = SchemaKeys.SCHEMA_DRAFT.value
+    schema["title"] = SchemaKeys.TITLE.value
+    schema["type"] = "object"
+    schema["properties"] = {
+        # Version number required for samconfig files to be valid
+        "version": {"type": "number"}
+    }
+    schema["required"] = ["version"]
+    schema["additionalProperties"] = False
+    # Iterate through packages for command and parameter information
     for package_name in _SAM_CLI_COMMAND_PACKAGES:
         new_command = retrieve_command_structure(package_name)
         commands.update(new_command)
         for param_list in new_command.values():
             command_params = [param for param in param_list]
         params.update(command_params)
+    # TODO: Generate schema for each of the commands
     return schema
 
 
+def write_schema():
+    """Generate the SAM CLI JSON schema and write it to file."""
+    schema = generate_schema()
+    with open(SchemaKeys.SCHEMA_FILE_NAME.value, "w+", encoding="utf-8") as outfile:
+        json.dump(schema, outfile, indent=2)
+
+
 if __name__ == "__main__":
     generate_schema()