From f6313f44653ccb0d6e7b92319ade907436802e72 Mon Sep 17 00:00:00 2001
From: nytpu <alex@nytpu.com>
Date: Tue, 16 Mar 2021 22:42:51 -0600
Subject: [PATCH] implement core package with structs, etc.

---
 core/structs.go | 144 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 144 insertions(+)
 create mode 100644 core/structs.go

diff --git a/core/structs.go b/core/structs.go
new file mode 100644
index 0000000..eec1473
--- /dev/null
+++ b/core/structs.go
@@ -0,0 +1,144 @@
+// Copyright (C) 2021 nytpu
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// For more license details, see LICENSE or <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+// This file incorporates code from makeworlds's amfora:
+// https://github.com/makeworld-the-better-one/amfora/blob/master/subscriptions/structs.go
+// Original source is Copyright 2020 makeworld and is licensed under the
+// terms of the GNU General Public License Version 3.0.
+// https://www.gnu.org/licenses/gpl-3.0-standalone.html
+
+// package core implements the structs and other necessary resources for storing
+// and managing feeds and pages
+package core
+
+import (
+	"net/url"
+	"sync"
+	"time"
+
+	"github.com/mmcdole/gofeed"
+)
+
+// jsonData is used for both reading from json and for storing the global feeds
+// map. contains read mutexes so concurrency can be used.
+type jsonData struct {
+	Feeds map[url.URL]*Feed `json:"feeds,omitempty"`
+	Pages map[url.URL]*Page `json:"pages,omitempty"`
+
+	feedsMu *sync.RWMutex
+	pagesMu *sync.RWMutex
+}
+
+// Feed holds all the necessary fields when storing a feed
+type Feed struct {
+	Title    string    `json:"title,omitempty"`
+	Link     *url.URL  `json:"link,omitempty"`     // link to the human-readable page for the feed. same as FeedLink for gemini feeds.
+	FeedLink *url.URL  `json:"feedlink,omitempty"` // link to the feed itself. if empty, use Link instead.
+	Updated  time.Time `json:"updated,omitempty"`
+	Items    []*Item   `json:"items,omitempty"`
+}
+
+// Item is a single item from a subscripton
+type Item struct {
+	Title     string    `json:"title,omitempty"` // if empty, use Link as title
+	Content   string    `json:"content,omitempty"`
+	Link      *url.URL  `json:"link,omitempty"`
+	Published time.Time `json:"updated,omitempty"`
+}
+
+// Page holds all the necessary fields when storing a page being watched for
+// changes.
+type Page struct {
+	Title   string    `json:"title,omitempty"`
+	Link    *url.URL  `json:"link,omitempty"`
+	Updated time.Time `json:"updated,omitempty"`
+	Hash    string    `json:"hash,omitempty"`
+}
+
+// gofeedConvert converts a gofeed.Feed into a Feed struct
+func GofeedConvert(f *gofeed.Feed, title string) (*Feed, error) {
+	new := &Feed{}
+
+	if title != "" {
+		new.Title = title
+	} else {
+		new.Title = f.Title
+	}
+	new.Updated = *f.UpdatedParsed
+	var err error
+	new.Link, err = url.ParseRequestURI(f.Link)
+	if err != nil {
+		return nil, err
+	}
+	new.FeedLink, err = url.ParseRequestURI(f.FeedLink)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, v := range f.Items {
+		item := &Item{}
+		item.Title = v.Title
+		item.Content = v.Content
+		item.Published = *v.PublishedParsed
+		item.Link, err = url.ParseRequestURI(f.FeedLink)
+		if err != nil {
+			return nil, err
+		}
+
+		new.Items = append(new.Items, item)
+	}
+
+	return new, nil
+}
+
+// Lock locks both feed and page mutexes.
+func (j *jsonData) Lock() {
+	j.feedsMu.Lock()
+	j.pagesMu.Lock()
+}
+
+// Unlock unlocks both feed and page mutexes.
+func (j *jsonData) Unlock() {
+	j.feedsMu.Unlock()
+	j.pagesMu.Unlock()
+}
+
+// RLock read-locks both feed and page mutexes.
+func (j *jsonData) RLock() {
+	j.feedsMu.RLock()
+	j.pagesMu.RLock()
+}
+
+// RUnlock read-unlocks both feed and page mutexes.
+func (j *jsonData) RUnlock() {
+	j.feedsMu.RUnlock()
+	j.pagesMu.RUnlock()
+}
+
+// PageEntry is a single item on a subscriptions page. It is used for both feeds
+// and pages.
+type PageEntry struct {
+	Prefix    string // whatever goes before the post title to identify the feed.
+	Title     string // article/entry title
+	URL       string
+	Published time.Time
+}
+
+// PageEntries is reverse chronological list of entries used when generating subs.
+type PageEntries struct {
+	Entries []*PageEntry
+}
+
+// Implement sort.Interface
+func (e *PageEntries) Len() int {
+	return len(e.Entries)
+}
+
+func (e *PageEntries) Less(i, j int) bool {
+	return e.Entries[i].Published.After(e.Entries[j].Published)
+}
+
+func (e *PageEntries) Swap(i, j int) {
+	e.Entries[i], e.Entries[j] = e.Entries[j], e.Entries[i]
+}