// SPDX-FileCopyrightText: 2026 Kerstin Humm <kerstin@erictapen.name>
//
// SPDX-License-Identifier: AGPL-3.0-or-later

import { Rule } from "../types.js";
import { buildReference } from "../utils.js";

export default {
  name: "startTime attribute",
  validate: (self) => {
    const rfc3339 =
      /^[1-9]\d{3}-\d{2}-\d{2}T\d{2}:\d{2}(:\d{2})?(Z|\+\d{2}:\d{2})$/;
    // const result: AnnotatedJson = { annotations: [], object: {} };

    if (!("startTime" in self || "previousStartTime" in self)) {
      return {
        annotations: [],
        object: {
          "startTime": {
            kind: "Violation",
            id: "NoStartTime",
            text:
              "The startTime field does not exist while there is also no previousStartTime field.",
            reference: buildReference({
              anchor: "object-type-event",
              text:
                "The startTime is not REQUIRED in case an event is postponed and a https://w3id.org/fep/8a8e/previousStartTime is set instead.",
            }),
          },
        },
      };
    }

    if (typeof self["startTime"] !== "string") {
      return {
        annotations: [],
        object: {
          "startTime": {
            kind: "Violation",
            id: "StartTimeNotAString",
            text: `The startTime field with value ${
              self["startTime"]
            } is not a String.`,
            reference: buildReference({
              anchor: "object-type-event",
              text:
                "The date and time when the event ends or is scheduled to end in the format as specified in the Activity Stream 2.0 specification.",
            }),
          },
        },
      };
    } else if (!rfc3339.test(self["startTime"])) {
      return {
        annotations: [],
        object: {
          "startTime": {
            kind: "Violation",
            id: "StartTimeNotRfc3339Compliant",
            text: `The startTime field with value ${
              self["startTime"]
            } is not compliant with RFC3339.`,
            reference: buildReference({
              anchor: "object-type-event",
              text:
                "The date and time when the event ends or is scheduled to end in the format as specified in the Activity Stream 2.0 specification.",
            }),
          },
        },
      };
    }

    return {
      annotations: [],
      object: {
        "startTime": {
          kind: "Correct",
          text: "Correct startTime",
        },
      },
    };
  },

  tests: [
    {
      value: {},
      result: { annotations: ["NoStartTime"], object: {} },
    },
    {
      value: { "startTime": "2014-12-31T23:00:00Z" },
      result: { annotations: [], object: { "startTime": "Correct" } },
    },
    // All properties with date and time values MUST conform to the "date-time" production in [RFC3339] with the one exception that seconds MAY be omitted.
    // https://www.w3.org/TR/activitystreams-core/#dates
    {
      value: { "startTime": "2014-12-31T23:00Z" },
      result: { annotations: [], object: { "startTime": "Correct" } },
    },
    {
      value: { "startTime": "invalid" },
      result: {
        annotations: [],
        object: { "startTime": "StartTimeNotRfc3339Compliant" },
      },
    },
    {
      value: {
        "startTime": "2014-12-31T23:00:00Z",
        "previousStartTime": "2014-12-31T23:00:00Z",
      },
      result: { annotations: [], object: { "startTime": "Correct" } },
    },
    {
      value: {
        "startTime": "2025-06-11T20:15:00+02:00",
      },
      result: { annotations: [], object: { "startTime": "Correct" } },
    },
  ],
} satisfies Rule;