// Resolve redirects from (deduplicated) pages, replacing them in the results.
// XXX: We only replace the row.doc, and not row.id, row.key, nor row.value.
async function resolveRedirects(pagesResult) {
// Get the targets of all docs' 'seeInstead' links.
const targetPageIds = pagesResult.rows.map(get('doc.seeInstead._id'))
.filter(x => x)
// If these pages contain no redirects, easy job for us.
if (targetPageIds.length === 0) return pagesResult
// Fetch the targeted pages.
// Note that multi-step redirections are resolved recursively here.
// XXX: a cycle of redirections would kill us.
const targetPagesResult = await getPages({
pageIds: targetPageIds,
followRedirects: true,
})
// Replace each page doc with its redirection target (if it had any).
const targetRowsById = resultRowsById(targetPagesResult)
const resolvedPagesResult = update('rows', rows => rows.map(
update('doc', doc => (!doc.seeInstead)
// Leave pages without a 'seeInstead' redirection link untouched...
? doc
// ...and replace the contents of the others with the correct page.
: {...targetRowsById[doc.seeInstead._id].doc}
)
))(pagesResult)
return resolvedPagesResult
}
// Nest the page docs into the visit docs, and return the latter.
async function insertPagesIntoVisits({ visitsResult, pagesResult }) {
// If pages are not already passed to us, get them.
if (pagesResult === undefined) {
// Get the page of each visit.
const pageIds = visitsResult.rows.map(row => row.doc.page._id)
pagesResult = await getPages({
pageIds,
// Assume that we always want to follow redirects.
followRedirects: true,
})
// Because the results are lined up, we can use a small optimisation and
// return directly.
return update('rows', rows =>
rows.map((row, i) =>
update('doc.page', () => pagesResult.rows[i].doc)(row),
),
)(visitsResult)
}
// Read each visit's doc.page._id and replace it with the specified page.
const pagesById = resultRowsById(pagesResult)
return update('rows', rows =>
rows.map(update('doc.page', page => pagesById[page._id].doc)),
)(visitsResult)
}