Add package for retrieving information from GOG (the changelog)

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/google/uuid v1.1.4
 	github.com/kr/pretty v0.2.1
 	github.com/pierrec/lz4/v4 v4.1.3
+	golang.org/x/net v0.0.0-20200301022130-244492dfa37a
 	golang.org/x/sys v0.0.0-20210108172913-0df2131ae363
 	gonum.org/v1/gonum v0.8.2
 )

gog/changelog.go

@@ -0,0 +1,224 @@
+package gog
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"strings"
+
+	"golang.org/x/net/html"
+	"golang.org/x/net/html/atom"
+)
+
+type Change struct {
+	Title   string
+	Changes []string
+	Sub     []Change
+	recurse bool
+}
+
+func (c Change) str(indent int) string {
+	var (
+		s   = new(strings.Builder)
+		ind = strings.Repeat("\t", indent)
+	)
+	fmt.Fprintln(s, ind+c.Title)
+	for _, v := range c.Changes {
+		fmt.Fprintln(s, ind+"\t"+v)
+	}
+	for _, v := range c.Sub {
+		s.WriteString(v.str(indent + 1))
+	}
+	// s.WriteRune('\n')
+	return s.String()
+}
+
+func (c Change) String() string {
+	return c.str(0)
+}
+
+func debug(f ...interface{}) {
+	if len(os.Args) > 2 && os.Args[2] == "debug" {
+		fmt.Println(f...)
+	}
+}
+
+// Stringify returns the text from a node and all its children
+func stringify(h *html.Node) string {
+	var (
+		f   func(*html.Node)
+		str string
+		def = h
+	)
+	f = func(n *html.Node) {
+		if n.Type == html.TextNode {
+			str += strings.TrimSpace(n.Data) + " "
+		}
+		if n.DataAtom == atom.Br {
+			str += "\n"
+		}
+		for c := n.FirstChild; c != nil; c = c.NextSibling {
+			f(c)
+		}
+	}
+	f(def)
+	return str
+}
+
+// ParseChange returns the parsed change and the next node to start parsing the next change
+func ParseChange(h *html.Node, title string) (Change, *html.Node) {
+	var c Change
+	c.Title = title
+	debug("change", strings.TrimSpace(h.Data))
+l:
+	for h.Data != "hr" {
+		switch h.Type {
+		case html.ErrorNode:
+			panic("An error happened!?!?")
+		case html.TextNode:
+			debug("text", strings.TrimSpace(h.Data))
+			if strings.TrimSpace(h.Data) != "" {
+				c.Changes = append(c.Changes, strings.TrimSpace(h.Data))
+			}
+		case html.ElementNode:
+			switch h.DataAtom {
+			case atom.H1, atom.H2, atom.H3, atom.H4, atom.H5, atom.H6, atom.P:
+				debug(h.DataAtom.String())
+				if c.Title == "" {
+					c.Title = strings.TrimSpace(stringify(h))
+				} else {
+					tmp := drain(h.NextSibling)
+					switch tmp.DataAtom {
+					case atom.H1, atom.H2, atom.H3, atom.H4, atom.H5, atom.H6:
+						h = tmp
+
+						c.Changes = append(c.Changes, strings.TrimSpace(stringify(h)))
+						break
+					}
+					var cc Change
+					debug("h", strings.TrimSpace(h.Data))
+					debug("h", strings.TrimSpace(h.NextSibling.Data))
+					cc, h = ParseChange(h.NextSibling, stringify(h))
+					debug("h2", h.Data, h.PrevSibling.Data)
+					// h = h.Parent
+					c.Sub = append(c.Sub, cc)
+					continue
+				}
+			case atom.Ul:
+				debug(h.DataAtom.String())
+				h = h.FirstChild
+				continue
+			case atom.Li:
+				debug("li", h.DataAtom.String())
+				if h.FirstChild != h.LastChild && h.FirstChild.NextSibling.DataAtom != atom.P && h.FirstChild.NextSibling.DataAtom != atom.A {
+					var cc Change
+					cc, h = ParseChange(h.FirstChild.NextSibling, strings.TrimSpace(h.FirstChild.Data))
+					h = h.Parent
+					if h.NextSibling != nil {
+						h = h.NextSibling
+					}
+					// pretty.Println(cc)
+					c.Sub = append(c.Sub, cc)
+					break l
+				}
+				fallthrough
+			default:
+				var (
+					f   func(*html.Node)
+					str string
+					def = h
+				)
+				f = func(n *html.Node) {
+					if n.Type == html.TextNode {
+						str += strings.TrimSpace(n.Data) + " "
+					}
+					for c := n.FirstChild; c != nil; c = c.NextSibling {
+						f(c)
+					}
+				}
+				f(def)
+				c.Changes = append(c.Changes, strings.TrimSpace(str))
+			}
+		}
+		if h.DataAtom == atom.Ul {
+			h = h.Parent
+		}
+		if h.NextSibling != nil { // Move to the next node, h should never be nil
+			debug("next", h.Type, h.NextSibling.Type)
+			h = h.NextSibling
+		} else if h.DataAtom == atom.Li || h.PrevSibling.DataAtom == atom.Li && h.Parent.DataAtom != atom.Body { // If we are currently in a list then go up one unless that would take us to body
+			debug("ul", strings.TrimSpace(h.Data), strings.TrimSpace(h.Parent.Data))
+			if h.Parent.NextSibling == nil {
+				h = h.Parent
+			} else { // go to parents next sibling so we don't parse the same node again
+				h = h.Parent.NextSibling
+			}
+			debug("break2", strings.TrimSpace(h.Data))
+			break
+		} else {
+			debug("I don't believe this should ever happen")
+			break
+		}
+	}
+	h = drain(h)
+	return c, h
+}
+
+// drain skips over non-Element Nodes
+func drain(h *html.Node) *html.Node {
+	for h.NextSibling != nil {
+		if h.Type == html.ElementNode {
+			break
+		}
+		h = h.NextSibling
+	}
+	return h
+}
+
+func ParseChangelog(ch, title string) (Change, error) {
+	var (
+		p   *html.Node
+		v   Change
+		err error
+	)
+	v.Title = title
+	p, err = html.Parse(strings.NewReader(ch))
+	if err != nil {
+		return v, err
+	}
+	p = p.FirstChild.FirstChild.NextSibling.FirstChild
+	for p != nil && p.NextSibling != nil {
+		var tmp Change
+		tmp, p = ParseChange(p, "")
+		if p.DataAtom == atom.Hr {
+			p = p.NextSibling
+		}
+		v.Sub = append(v.Sub, tmp)
+	}
+	return v, nil
+}
+
+func getGOGInfo(id string) (GOGalaxy, error) {
+	var (
+		r    *http.Response
+		err  error
+		b    []byte
+		info GOGalaxy
+	)
+	r, err = http.Get("https://api.gog.com/products/" + id + "?expand=downloads,expanded_dlcs,description,screenshots,videos,related_products,changelog")
+	if err != nil {
+		return GOGalaxy{}, fmt.Errorf("failed to retrieve GOG info: %w", err)
+	}
+	b, err = ioutil.ReadAll(r.Body)
+	if err != nil {
+		return GOGalaxy{}, fmt.Errorf("failed to retrieve GOG info: %w", err)
+	}
+	r.Body.Close()
+	err = json.Unmarshal(b, &info)
+	if err != nil {
+		return GOGalaxy{}, fmt.Errorf("failed to retrieve GOG info: %w", err)
+	}
+	return info, nil
+}

gog/gog.go

@@ -0,0 +1,202 @@
+package gog
+
+import (
+	"bytes"
+	"encoding/json"
+	"reflect"
+	"time"
+)
+
+type GOGalaxy struct {
+	ID                         int    `json:"id"`
+	Title                      string `json:"title"`
+	PurchaseLink               string `json:"purchase_link"`
+	Slug                       string `json:"slug"`
+	ContentSystemCompatibility struct {
+		Windows bool `json:"windows"`
+		Osx     bool `json:"osx"`
+		Linux   bool `json:"linux"`
+	} `json:"content_system_compatibility"`
+	Languages map[string]string `json:"languages"`
+	Links     struct {
+		PurchaseLink string `json:"purchase_link"`
+		ProductCard  string `json:"product_card"`
+		Support      string `json:"support"`
+		Forum        string `json:"forum"`
+	} `json:"links"`
+	InDevelopment struct {
+		Active bool        `json:"active"`
+		Until  interface{} `json:"until"`
+	} `json:"in_development"`
+	IsSecret      bool      `json:"is_secret"`
+	IsInstallable bool      `json:"is_installable"`
+	GameType      string    `json:"game_type"`
+	IsPreOrder    bool      `json:"is_pre_order"`
+	ReleaseDate   time.Time `json:"release_date"`
+	Images        Images    `json:"images"`
+	Dlcs          DLCs      `json:"dlcs"`
+	Downloads     struct {
+		Installers    []Download `json:"installers"`
+		Patches       []Download `json:"patches"`
+		LanguagePacks []Download `json:"language_packs"`
+		BonusContent  []Download `json:"bonus_content"`
+	} `json:"downloads"`
+	ExpandedDlcs []Product `json:"expanded_dlcs"`
+	Description  struct {
+		Lead             string `json:"lead"`
+		Full             string `json:"full"`
+		WhatsCoolAboutIt string `json:"whats_cool_about_it"`
+	} `json:"description"`
+	Screenshots []struct {
+		ImageID              string `json:"image_id"`
+		FormatterTemplateURL string `json:"formatter_template_url"`
+		FormattedImages      []struct {
+			FormatterName string `json:"formatter_name"`
+			ImageURL      string `json:"image_url"`
+		} `json:"formatted_images"`
+	} `json:"screenshots"`
+	Videos []struct {
+		VideoURL     string `json:"video_url"`
+		ThumbnailURL string `json:"thumbnail_url"`
+		Provider     string `json:"provider"`
+	} `json:"videos"`
+	RelatedProducts []Product `json:"related_products"`
+	Changelog       string    `json:"changelog"`
+}
+
+func (gog *GOGalaxy) UnmarshalJSON(d []byte) error {
+	var err error
+	type T2 GOGalaxy // create new type with same structure as T but without its method set to avoid infinite `UnmarshalJSON` call stack
+	x := struct {
+		T2
+		ReleaseDate string `json:"release_date"`
+	}{} // don't forget this, if you do and 't' already has some fields set you would lose them; see second example
+
+	if err = json.Unmarshal(d, &x); err != nil {
+		return err
+	}
+	*gog = GOGalaxy(x.T2)
+
+	if gog.ReleaseDate, err = time.Parse("2006-01-02T15:04:05-0700", x.ReleaseDate); err != nil {
+		return err
+	}
+	return nil
+}
+
+type DLCs struct {
+	Products []struct {
+		ID           int    `json:"id"`
+		Link         string `json:"link"`
+		ExpandedLink string `json:"expanded_link"`
+	} `json:"products"`
+	AllProductsURL         string `json:"all_products_url"`
+	ExpandedAllProductsURL string `json:"expanded_all_products_url"`
+}
+
+func (DLC *DLCs) UnmarshalJSON(d []byte) error {
+	type T2 GOGalaxy
+	var x T2
+	dec := json.NewDecoder(bytes.NewBuffer(d))
+	t, err := dec.Token()
+	if err != nil {
+		return err
+	}
+	if delim, ok := t.(json.Delim); ok {
+		if delim == '[' {
+			return nil
+		} else {
+			return json.Unmarshal(d, &x)
+		}
+	} else {
+		return &json.UnmarshalTypeError{
+			Value:  reflect.TypeOf(t).String(),
+			Type:   reflect.TypeOf(*DLC),
+			Offset: 0,
+			Struct: "DLCs",
+			Field:  ".",
+		}
+	}
+}
+
+type Languages map[string]string
+
+type Download struct {
+	ID           string `json:"id"`
+	Name         string `json:"name"`
+	Os           string `json:"os"`
+	Language     string `json:"language"`
+	LanguageFull string `json:"language_full"`
+	Version      string `json:"version"`
+	TotalSize    int64  `json:"total_size"`
+	Files        []File `json:"files"`
+}
+
+func (d *Download) UnmarshalJSON(data []byte) error {
+	var i json.Number
+	type T2 Download // create new type with same structure as T but without its method set to avoid infinite `UnmarshalJSON` call stack
+	x := struct {
+		T2
+		ID json.RawMessage `json:"id"`
+	}{} // don't forget this, if you do and 't' already has some fields set you would lose them; see second example
+
+	if err := json.Unmarshal(data, &x); err != nil {
+		return err
+	}
+	*d = Download(x.T2)
+	if err := json.Unmarshal(x.ID, &i); err != nil {
+		if err := json.Unmarshal(x.ID, &d.ID); err != nil {
+			return err
+		} else {
+			return nil
+		}
+		return err
+	}
+	d.ID = i.String()
+	return nil
+}
+
+type File struct {
+	ID       string `json:"id"`
+	Size     int    `json:"size"`
+	Downlink string `json:"downlink"`
+}
+
+type Product struct {
+	ID                         int    `json:"id"`
+	Title                      string `json:"title"`
+	PurchaseLink               string `json:"purchase_link"`
+	Slug                       string `json:"slug"`
+	ContentSystemCompatibility struct {
+		Windows bool `json:"windows"`
+		Osx     bool `json:"osx"`
+		Linux   bool `json:"linux"`
+	} `json:"content_system_compatibility"`
+	Links struct {
+		PurchaseLink string `json:"purchase_link"`
+		ProductCard  string `json:"product_card"`
+		Support      string `json:"support"`
+		Forum        string `json:"forum"`
+	} `json:"links"`
+	InDevelopment struct {
+		Active bool      `json:"active"`
+		Until  time.Time `json:"until"`
+	} `json:"in_development"`
+	IsSecret      bool      `json:"is_secret"`
+	IsInstallable bool      `json:"is_installable"`
+	GameType      string    `json:"game_type"`
+	IsPreOrder    bool      `json:"is_pre_order"`
+	ReleaseDate   string    `json:"release_date"`
+	Images        Images    `json:"images"`
+	Languages     Languages `json:"languages,omitempty"`
+}
+
+type Images struct {
+	Background          string `json:"background"`
+	Logo                string `json:"logo"`
+	Logo2X              string `json:"logo2x"`
+	Icon                string `json:"icon"`
+	SidebarIcon         string `json:"sidebarIcon"`
+	SidebarIcon2X       string `json:"sidebarIcon2x"`
+	MenuNotificationAv  string `json:"menuNotificationAv"`
+	MenuNotificationAv2 string `json:"menuNotificationAv2"`
+}