Actually implement the CLI "payload" option

Signed-off-by: Mathias L. Baumann <[email protected]>

Author: Marenz

src/frequenz/client/dispatch/__main__.py

@@ -17,7 +17,13 @@
 from prompt_toolkit.patch_stdout import patch_stdout
 from prompt_toolkit.shortcuts import CompleteStyle
 
-from ._cli_types import FuzzyDateTime, FuzzyIntRange, FuzzyTimeDelta, SelectorParamType
+from ._cli_types import (
+    FuzzyDateTime,
+    FuzzyIntRange,
+    FuzzyTimeDelta,
+    JsonParamType,
+    SelectorParamType,
+)
 from ._client import Client
 
 DEFAULT_DISPATCH_API_HOST = "88.99.25.81"
@@ -104,7 +110,9 @@ async def list_(ctx: click.Context, /, **filters: Any) -> None:
 @click.argument("selector", required=True, type=SelectorParamType())
 @click.option("--active", "-a", type=bool, default=True)
 @click.option("--dry-run", "-d", type=bool, default=False)
-@click.option("--payload", type=str, help="JSON payload for the dispatch")
+@click.option(
+    "--payload", "-p", type=JsonParamType(), help="JSON payload for the dispatch"
+)
 @click.option("--recurrence", type=str, help="Recurrence rule (see documentation)")
 @click.pass_context
 async def create(

src/frequenz/client/dispatch/_cli_types.py

@@ -3,6 +3,7 @@
 
 """Types for the CLI client."""
 
+import json
 from datetime import datetime, timedelta, timezone
 from typing import Any, cast
 
@@ -167,3 +168,36 @@ def convert(
                 param,
                 ctx,
             )
+
+
+class JsonParamType(click.ParamType):
+    """Click parameter type for JSON strings."""
+
+    name = "json"
+
+    def convert(
+        self, value: Any, param: click.Parameter | None, ctx: click.Context | None
+    ) -> dict[str, Any]:
+        """Convert the input value into a dictionary.
+
+        Args:
+            value: The input value (string).
+            param: The Click parameter object.
+            ctx: The Click context object.
+
+        Returns:
+            A dictionary parsed from the input JSON string.
+        """
+        if isinstance(value, dict):  # Already a dictionary
+            return value
+
+        try:
+            if not value.startswith("{"):
+                value = "{" + value
+            if not value.endswith("}"):
+                value = value + "}"
+
+            return cast(dict[str, Any], json.loads(value))
+
+        except ValueError as e:
+            self.fail(f"Invalid JSON string: {value}. Error: {e}", param, ctx)