kama/services.go

// apcore is a server framework for implementing an ActivityPub application.
// Copyright (C) 2019 Cory Slep
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package main

import (
	"context"
	"net/url"

	"github.com/go-fed/activity/streams"
	"github.com/go-fed/activity/streams/vocab"
	"github.com/go-fed/apcore/app"
	"github.com/go-fed/apcore/models"
	"github.com/go-fed/apcore/util"
)

func getLatestPublicNotes(ctx context.Context, db app.Database) (notes []vocab.Type, err error) {
	return getNotes(ctx, db, `WITH local_notes AS(
  SELECT payload, create_time FROM %[1]slocal_data
  WHERE payload->>'type' = 'Note' AND (
    payload->'to' ? 'https://www.w3.org/ns/activitystreams#Public'
    OR payload->'cc' ? 'https://www.w3.org/ns/activitystreams#Public')
), fed_notes AS (
  SELECT payload, create_time FROM %[1]sfed_data
  WHERE payload->>'type' = 'Note' AND (
    payload->'to' ? 'https://www.w3.org/ns/activitystreams#Public'
    OR payload->'cc' ? 'https://www.w3.org/ns/activitystreams#Public')
), unioned AS (
SELECT payload, create_time FROM local_notes
UNION
SELECT payload, create_time FROM fed_notes
), deduped AS (
  SELECT
    DISTINCT ON (payload->'id') payload,
    create_time
  FROM unioned
  ORDER BY payload->'id'
)
SELECT payload FROM deduped
ORDER BY create_time DESC
LIMIT 10`)
}

func getLatestNotesAndMyPrivateNotes(ctx context.Context, db app.Database, userIRI string) (notes []vocab.Type, err error) {
	return getNotes(ctx, db, `WITH local_notes AS(
  SELECT payload, create_time FROM %[1]slocal_data
  WHERE payload->>'type' = 'Note' AND (
    payload->'to' ? 'https://www.w3.org/ns/activitystreams#Public'
    OR payload->'cc' ? 'https://www.w3.org/ns/activitystreams#Public'
    OR payload->>'attributedTo' = $1
    OR payload->'to' ? $1
    OR payload->'cc' ? $1)
), fed_notes AS (
  SELECT payload, create_time FROM %[1]sfed_data
  WHERE payload->>'type' = 'Note' AND (
    payload->'to' ? 'https://www.w3.org/ns/activitystreams#Public'
    OR payload->'cc' ? 'https://www.w3.org/ns/activitystreams#Public'
    OR payload->>'attributedTo' = $1
    OR payload->'to' ? $1
    OR payload->'cc' ? $1)
), unioned AS (
SELECT payload, create_time FROM local_notes
UNION
SELECT payload, create_time FROM fed_notes
), deduped AS (
  SELECT
    DISTINCT ON (payload->'id') payload,
    create_time
  FROM unioned
  ORDER BY payload->'id'
)
SELECT payload
FROM deduped
ORDER BY create_time DESC
LIMIT 10`,
		userIRI)
}

func getNotes(ctx context.Context, db app.Database, sql string, data ...interface{}) (notes []vocab.Type, err error) {
	c := util.Context{ctx}
	var rz *streams.TypeResolver
	rz, err = streams.NewTypeResolver(func(c context.Context, note vocab.ActivityStreamsNote) error {
		notes = append(notes, note)
		return nil
	})
	if err != nil {
		return
	}
	txb := db.Begin()
	txb.Query(sql,
		func(r app.SingleRow) error {
			var v models.ActivityStreams
			if err := r.Scan(&v); err != nil {
				return err
			}
			return rz.Resolve(c.Context, v.Type)
		},
		data...)
	err = txb.Do(c)
	return
}

func getUsers(ctx context.Context, db app.Database) (ppl []vocab.Type, err error) {
	c := util.Context{ctx}
	var rz *streams.TypeResolver
	rz, err = streams.NewTypeResolver(func(c context.Context, pn vocab.ActivityStreamsPerson) error {
		ppl = append(ppl, pn)
		return nil
	})
	if err != nil {
		return
	}
	txb := db.Begin()
	txb.Query(`SELECT actor FROM %[1]susers
WHERE actor->>'type' = 'Person'
ORDER BY create_time DESC`,
		func(r app.SingleRow) error {
			var v models.ActivityStreams
			if err := r.Scan(&v); err != nil {
				return err
			}
			return rz.Resolve(c.Context, v.Type)
		})
	err = txb.Do(c)
	return
}

func getNoteIsReadable(ctx util.Context, db app.Database, noteID, userID *url.URL) (legible /*lol*/ bool, err error) {
	txb := db.Begin()
	txb.Query(`SELECT EXISTS (
SELECT create_time FROM %[1]slocal_data
WHERE payload->>'type' = 'Note' AND (
  payload->'to' ? 'https://www.w3.org/ns/activitystreams#Public'
  OR payload->'cc' ? 'https://www.w3.org/ns/activitystreams#Public'
  OR payload->>'attributedTo' = $2
  OR payload->'to' ? $2
  OR payload->'cc' ? $2)
  AND payload->>'id' = $1)`,
		func(r app.SingleRow) error {
			return r.Scan(&legible)
		},
		noteID.String(), userID.String())
	err = txb.Do(ctx)
	return
}

func getNoteIsPublic(ctx util.Context, db app.Database, noteID *url.URL) (pub bool, err error) {
	txb := db.Begin()
	txb.Query(`SELECT EXISTS (
SELECT create_time FROM %[1]slocal_data
WHERE payload->>'type' = 'Note' AND (
  payload->'to' ? 'https://www.w3.org/ns/activitystreams#Public'
  OR payload->'cc' ? 'https://www.w3.org/ns/activitystreams#Public')
  AND payload->>'id' = $1)`,
		func(r app.SingleRow) error {
			return r.Scan(&pub)
		},
		noteID.String())
	err = txb.Do(ctx)
	return
}