const { MIME_TYPES } = require('@semapps/mime-types');

// Version-skew compatibility shim for the app registration handshake.
//
// `@activitypods/app` 2.3.2 (app side) and the local pod provider (HEAD) disagree on where
// an AccessGrant records the access needs it satisfies. The app-side `app-registrations.verify`
// tests `accessGrant['interop:satisfiesAccessNeed']` directly on the AccessGrant — the umbrella
// grant the pod lists in `interop:hasAccessGrant`. The pod provider now writes
// `interop:satisfiesAccessNeed` on the DataGrants instead, reached through
// AccessGrant -> `interop:hasDataGrant` -> DataGrant. The original test therefore never matches,
// verify returns `accessNeedsSatisfied: false`, the inbox processor throws
// "One or more required access needs have not been granted", the local AppRegistration is never
// stored, and the consent flow loops back to `/login?register_app=true`.
//
// This shim reimplements the original `verify` verbatim, with the access-need test resolving
// through DataGrants (falling back to the grant itself when it carries no DataGrant, so it
// tolerates both the old and the new pod-side shape). It is installed as a broker middleware
// because the target action lives inside the `@activitypods/app` package: the service itself is
// registered by that package, so the handler cannot be overridden by a normal mixin. The
// middleware is added to `broker.middlewares` in `created()`, before the services that expose
// `app-registrations.verify` are constructed, so it wraps every local action; only
// `app-registrations.verify` is intercepted.
//
// This is a workaround for platform drift, not a Festipod concern: the proper fix belongs
// upstream in `@activitypods/app`, and is reported to the provider rather than worked around there.

const arrayOf = value => (value === undefined || value === null ? [] : Array.isArray(value) ? value : [value]);

module.exports = {
  name: 'apods-verify-compat',
  created() {
    this.broker.middlewares.add({
      name: 'ApodsVerifyCompat',
      localAction(next, action) {
        if (action.name !== 'app-registrations.verify') return next;

        return async ctx => {
          const { appRegistrationUri } = ctx.params;

          // Use local context to get all data
          const jsonContext = await ctx.call('jsonld.context.get');

          // Get from remote server, not local cache, to get latest version
          const appRegistration = await ctx.call('ldp.remote.getNetwork', {
            resourceUri: appRegistrationUri,
            jsonContext
          });

          const accessGrants = await Promise.all(
            arrayOf(appRegistration['interop:hasAccessGrant']).map(grantUri =>
              ctx.call('ldp.remote.get', {
                resourceUri: grantUri,
                jsonContext,
                accept: MIME_TYPES.JSON
              })
            )
          );

          // Resolve each grant's DataGrants, where the pod provider now records the
          // satisfied access needs (AccessGrant -> interop:hasDataGrant -> DataGrant).
          const grantsWithDataGrants = await Promise.all(
            accessGrants.map(async grant => ({
              grant,
              dataGrants: await Promise.all(
                arrayOf(grant['interop:hasDataGrant']).map(dataGrantUri =>
                  ctx.call('ldp.remote.get', {
                    resourceUri: dataGrantUri,
                    jsonContext,
                    accept: MIME_TYPES.JSON
                  })
                )
              )
            }))
          );

          const satisfiesAccessNeed = accessNeedUri =>
            grantsWithDataGrants.some(
              ({ grant, dataGrants }) =>
                dataGrants.some(dataGrant => dataGrant['interop:satisfiesAccessNeed'] === accessNeedUri) ||
                grant['interop:satisfiesAccessNeed'] === accessNeedUri
            );

          // Get required access need group(s)
          const filteredContainer = await ctx.call('access-needs-groups.list', {
            filters: {
              'http://www.w3.org/ns/solid/interop#accessNecessity': 'http://www.w3.org/ns/solid/interop#AccessRequired'
            },
            accept: MIME_TYPES.JSON
          });
          const requiredAccessNeedGroups = arrayOf(filteredContainer['ldp:contains']);

          // Return true if all access needs and special rights of the required AccessNeedGroup(s) are granted
          const accessNeedsSatisfied = requiredAccessNeedGroups.every(
            group =>
              arrayOf(group['interop:hasAccessNeed']).every(accessNeedUri => satisfiesAccessNeed(accessNeedUri)) &&
              arrayOf(group['interop:hasSpecialRights']).every(specialRightUri =>
                appRegistration['apods:hasSpecialRights'].some(sr => sr === specialRightUri)
              )
          );

          return { accessNeedsSatisfied, appRegistration, accessGrants };
        };
      }
    });
  }
};