3 files changed, 129 insertions, 0 deletions
diff --git a/src/wikipedia/api.go b/src/wikipedia/api.go
new file mode 100644
index 0000000..fb06518
--- /dev/null
+++ b/src/wikipedia/api.go
@@ -0,0 +1,17 @@
+package wikipedia
+
+type APIResponse struct {
+	Continue *struct {
+		Continue   string `json:"continue"`
+		LlContinue string `json:"llcontinue"`
+	} `json:"continue"`
+	Query struct {
+		Pages []struct {
+			Title     string `json:"title"`
+			LangLinks *[]struct {
+				Lang  string `json:"lang"`
+				Title string `json:"title"`
+			} `json:"langlinks"`
+		} `json:"pages"`
+	} `json:"query"`
+}
diff --git a/src/wikipedia/links.gen.go b/src/wikipedia/links.gen.go
new file mode 100644
index 0000000..42900cc
--- /dev/null
+++ b/src/wikipedia/links.gen.go
@@ -0,0 +1,13 @@
+// Code generated by extwiki.  DO NOT EDIT.
+
+package wikipedia
+
+var extractedTitles = [...]string{
+	"Coat of arms of Andorra",
+	"Coat of arms of Germany",
+	"Dubravka (drama)",
+	"Eurovision Song Contest",
+	"Glagolitic script",
+	"Nikola Tesla",
+	"Royal cypher",
+}
diff --git a/src/wikipedia/wikipedia.go b/src/wikipedia/wikipedia.go
new file mode 100644
index 0000000..e55e9da
--- /dev/null
+++ b/src/wikipedia/wikipedia.go
@@ -0,0 +1,99 @@
+package wikipedia
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var (
+	defaultLocale string
+	titlemap      = make(map[string]map[string]string)
+)
+
+func Init(locale string) error {
+	defaultLocale = locale
+	base := fmt.Sprintf("https://%s.wikipedia.org/w/api.php", defaultLocale)
+	u, err := url.Parse(base)
+	if err != nil {
+		return err
+	}
+
+	var resp APIResponse
+	titles := strings.Join(extractedTitles[:], "|")
+
+	q := u.Query()
+	q.Set("action", "query")
+	q.Set("format", "json")
+	q.Set("prop", "langlinks")
+	q.Set("titles", titles)
+	q.Set("formatversion", "2")
+	q.Set("lllimit", "max")
+
+	for {
+		if resp.Continue != nil {
+			q.Set("continue", resp.Continue.Continue)
+			q.Set("llcontinue", resp.Continue.LlContinue)
+		}
+		u.RawQuery = q.Encode()
+
+		respjson, err := http.Get(u.String())
+		if err != nil {
+			return err
+		}
+		if respjson.StatusCode >= 400 &&
+			respjson.StatusCode != http.StatusTooManyRequests {
+			return fmt.Errorf("Failed to GET %s: %s", u, respjson.Status)
+		}
+		defer respjson.Body.Close()
+
+		secs, err := strconv.Atoi(respjson.Header.Get("Retry-After"))
+		if err != nil {
+			time.Sleep(time.Duration(secs) * time.Second)
+		}
+
+		body, err := io.ReadAll(respjson.Body)
+		if err != nil {
+			return err
+		}
+
+		resp = APIResponse{}
+		if err = json.Unmarshal(body, &resp); err != nil {
+			return err
+		}
+
+		for _, page := range resp.Query.Pages {
+			if page.LangLinks == nil {
+				continue
+			}
+
+			t := url.PathEscape(page.Title)
+			if _, ok := titlemap[t]; !ok {
+				titlemap[t] = make(map[string]string)
+			}
+
+			for _, ll := range *page.LangLinks {
+				titlemap[t][ll.Lang] = url.PathEscape(ll.Title)
+			}
+		}
+
+		if resp.Continue == nil {
+			return nil
+		}
+	}
+}
+
+func Url(title, locale string) string {
+	base := "https://%s.wikipedia.org/wiki/%s"
+	title = url.PathEscape(title)
+	t, ok := titlemap[title][locale]
+	if !ok {
+		t, locale = title, defaultLocale
+	}
+	return fmt.Sprintf(base, locale, t)
+}