import { dimensionLabDashboardFixture } from "$lib/model/fixtures/dimensionlab";
import type { DashboardDocument } from "$lib/model";
import {
  createDashboardStore,
  DashboardPersistenceValidationError,
  type DashboardStore,
} from "$lib/server/db/dashboard-store";
import { UnsupportedDashboardModelVersionError } from "$lib/server/db/model-migrations";

export type DashboardRuntimeState =
  | DashboardRuntimeEmpty
  | DashboardRuntimeInvalid
  | DashboardRuntimeReady;

export interface DashboardRuntimeReady {
  state: "ready";
  document: DashboardDocument;
  schemaVersion: string;
  currentRevisionId: string;
}

export interface DashboardRuntimeEmpty {
  state: "empty";
  title: string;
  subtitle: string;
  message: string;
}

export interface DashboardRuntimeInvalid {
  state: "invalid";
  title: string;
  subtitle: string;
  message: string;
  errors: string[];
}

export function loadDashboardRuntime(
  store?: DashboardStore,
): DashboardRuntimeState {
  const dashboardStore = store || createDashboardStore();

  try {
    const seeded = dashboardStore.seedDashboardIfEmpty(dimensionLabDashboardFixture, {
      actor: "initial-seed",
      message: "load initial dashboard document",
    });
    const active = dashboardStore.getActiveDashboard();
    const document = active?.document || seeded.document;
    const currentRevisionId = active?.currentRevisionId || seeded.id;

    if (!document) {
      return {
        state: "empty",
        title: "No Dashboard Model",
        subtitle: "No active document",
        message: "No validated dashboard document is active yet.",
      };
    }

    return {
      state: "ready",
      document,
      schemaVersion: document.schemaVersion,
      currentRevisionId,
    };
  } catch (error) {
    if (error instanceof DashboardPersistenceValidationError) {
      return invalidRuntimeState(error.failure.errors);
    }

    if (error instanceof UnsupportedDashboardModelVersionError) {
      return invalidRuntimeState([error.message]);
    }

    throw error;
  } finally {
    if (!store) dashboardStore.close();
  }
}

function invalidRuntimeState(errors: string[]): DashboardRuntimeInvalid {
  return {
    state: "invalid",
    title: "Invalid Dashboard Model",
    subtitle: "Validation failed",
    message: "The active dashboard document could not be validated.",
    errors,
  };
}