2 files changed, 220 insertions, 0 deletions

diff --git a/goanilist.go b/goanilist.go
new file mode 100644
index 0000000..54cdaf8
--- /dev/null
+++ b/goanilist.go
@@ -0,0 +1,172 @@
+package goanilist
+
+import (
+        "database/sql"
+        "encoding/json"
+        "errors"
+        "fmt"
+        "io/ioutil"
+        "log"
+        "net/http"
+        "net/url"
+        "time"
+)
+
+const API_URL = "https://anilist.co/api/"
+
+var (
+        ErrAnilistCoupled    = errors.New("Anilist is already coupled!")
+        ErrAnilistNotCoupled = errors.New("Anilist is not coupled")
+)
+
+var httpClient = &http.Client{}
+
+type Client struct {
+        db           *sql.DB
+        user         int
+        id           string
+        secret       string
+        token        string
+        refreshToken string
+        tokenExpires int64
+        IsCoupled    bool
+}
+
+func NewClient(db *sql.DB, user int, id, secret string) *Client {
+        c := &Client{
+                db:     db,
+                user:   user,
+                id:     id,
+                secret: secret,
+        }
+        err := db.QueryRow("SELECT token, refresh_token FROM login.anilist_api_tokens WHERE user_id = $1;", user).Scan(&c.token, &c.refreshToken)
+        c.IsCoupled = err == nil
+        return c
+}
+
+func (c *Client) AuthorizeURL() string {
+        return fmt.Sprintf("%sauth/authorize?grant_type=%s&client_id=%s&response_type=%s",
+                API_URL,
+                "authorization_pin",
+                url.QueryEscape(c.id),
+                "pin")
+}
+
+func (c *Client) NeedsToRenew() bool {
+        t := time.Now().UTC().Unix()
+        return t > (c.tokenExpires - 60) //60 seconds of buffer time
+}
+
+func (c *Client) CoupleByPin(pin string) error {
+        if c.IsCoupled {
+                return ErrAnilistCoupled
+        }
+        res := AccessTokenResult{}
+        err := c.post("auth/access_token", url.Values{
+                "grant_type":    {"authorization_pin"},
+                "client_id":     {c.id},
+                "client_secret": {c.secret},
+                "code":          {pin},
+        }, &res)
+        switch res.Error {
+        case "invalid_request":
+                err = errors.New("Der eingegebene Code ist nicht korrekt. Bitte prüfe, ob du ihn richtig kopiert hast.")
+        }
+        if err != nil {
+                return err
+        }
+        _, err = c.db.Exec("INSERT INTO login.anilist_api_tokens (user_id, token, refresh_token) VALUES ($1, $2, $3);", c.user, res.AccessToken, res.RefreshToken)
+        if err != nil {
+                return err
+        }
+        c.token = res.AccessToken
+        c.refreshToken = res.RefreshToken
+        c.tokenExpires = res.Expires
+        return nil
+}
+
+func (c *Client) RenewToken() error {
+        if !c.IsCoupled {
+                return ErrAnilistNotCoupled
+        }
+        log.Println("Token expired, get new token..")
+        res := AccessTokenResult{}
+        err := c.post("auth/access_token", url.Values{
+                "grant_type":    {"refresh_token"},
+                "client_id":     {c.id},
+                "client_secret": {c.secret},
+                "refresh_token": {c.refreshToken},
+        }, &res)
+        if err != nil {
+                return err
+        }
+        _, err = c.db.Exec("UPDATE login.anilist_api_tokens SET token = $1 WHERE user_id = $2;", res.AccessToken, c.user)
+        if err != nil {
+                return err
+        }
+        c.token = res.AccessToken
+        c.tokenExpires = res.Expires
+        return nil
+}
+
+func (c *Client) User() (*UserResult, error) {
+        if !c.IsCoupled {
+                return nil, ErrAnilistNotCoupled
+        }
+        if c.NeedsToRenew() {
+                if err := c.RenewToken(); err != nil {
+                        return nil, err
+                }
+        }
+        res := &UserResult{}
+        err := c.get("user", res)
+        if err != nil {
+                return nil, err
+        }
+        return res, nil
+}
+
+func (c *Client) post(path string, values url.Values, result interface{}) error {
+        resp, err := http.PostForm(fmt.Sprintf("%s%s", API_URL, path), values)
+        if err != nil {
+                return err
+        }
+        return c.handleResponse(resp, path, values, result)
+}
+
+func (c *Client) get(path string, result interface{}) error {
+        req, err := http.NewRequest("GET", fmt.Sprintf("%s%s", API_URL, path), nil)
+        if err != nil {
+                return err
+        }
+        req.Header.Add("Authorization", "Bearer "+c.token)
+        resp, err := httpClient.Do(req)
+        if err != nil {
+                return err
+        }
+        return c.handleResponse(resp, path, url.Values{}, result)
+}
+
+func (c *Client) handleResponse(resp *http.Response, path string, values url.Values, result interface{}) error {
+        body, err := ioutil.ReadAll(resp.Body)
+        if err != nil {
+                return err
+        }
+        err = json.Unmarshal(body, result)
+        if err != nil {
+                log.Println(string(body))
+                return err
+        }
+        resErr := result.(APIError).Get()
+        resErr.ParseRawError()
+        if resp.StatusCode != 200 {
+                log.Printf("%s: %v -> %s\n", path, values, resp.Status)
+                if resErr.Error != "" {
+                        log.Printf("%v\n", resErr)
+                        return errors.New(fmt.Sprintf("%s: %s", resErr.Error, resErr.ErrorMessage))
+                } else {
+                        return errors.New(resp.Status)
+                }
+        }
+        return nil
+}
diff --git a/types.go b/types.go
new file mode 100644
index 0000000..e451806
--- /dev/null
+++ b/types.go
@@ -0,0 +1,48 @@
+package goanilist
+
+import "encoding/json"
+
+type APIError interface {
+        Get() *FlexibleError
+}
+
+type FlexibleError struct {
+        RawError     json.RawMessage `json:"error"`
+        Error        string
+        ErrorMessage string `json:"error_message"`
+}
+
+type complexError struct {
+        Error            string `json:"error"`
+        ErrorDescription string `json:"error_description"`
+}
+
+func (e *FlexibleError) ParseRawError() {
+        ce := complexError{}
+        err := json.Unmarshal(e.RawError, &ce)
+        if err == nil {
+                e.Error = ce.Error
+                e.ErrorMessage = ce.ErrorDescription
+        } else {
+                e.Error = string(e.RawError)
+        }
+}
+
+func (e *FlexibleError) Get() *FlexibleError {
+        return e
+}
+
+type AccessTokenResult struct {
+        FlexibleError
+        AccessToken  string `json:"access_token"`
+        TokenType    string `json:"token_type"`
+        Expires      int64  `json:"expires"`
+        ExpiresIn    int    `json:"expires_in"`
+        RefreshToken string `json:"refresh_token"`
+}
+
+type UserResult struct {
+        FlexibleError
+        ID          int    `json:"id"`
+        DisplayName string `json:"display_name"`
+}