feat: add and get records methods (initial commit)

client.go

@@ -0,0 +1,145 @@
+// Copyright © 2020 Mike Berezin
+//
+// Use of this source code is governed by an MIT license.
+// Details in the LICENSE file.
+
+package airtable
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+const (
+	airtableBaseURL = "https://api.airtable.com/v0"
+	rateLimit       = 4
+)
+
+// Client client for airtable api
+type Client struct {
+	client      *http.Client
+	rateLimiter <-chan time.Time
+	baseURL     string
+	apiKey      string
+}
+
+// NewClient airtable client constructor
+// your API KEY you can get on your account page
+// https://airtable.com/account
+func NewClient(apiKey string) *Client {
+	return &Client{
+		client:      http.DefaultClient,
+		rateLimiter: time.Tick(time.Second / time.Duration(rateLimit)),
+		apiKey:      apiKey,
+		baseURL:     airtableBaseURL,
+	}
+}
+
+// SetRateLimit rate limit setter for custom usage
+// Airtable limit is 5 requests per second (we use 4)
+// https://airtable.com/{yourDatabaseID}/api/docs#curl/ratelimits
+func (at *Client) SetRateLimit(customRateLimit int) {
+	at.rateLimiter = time.Tick(time.Second / time.Duration(customRateLimit))
+}
+
+func (at *Client) rateLimit() {
+	<-at.rateLimiter
+}
+
+func (at *Client) get(db, table, recordID string, params url.Values, target interface{}) error {
+	at.rateLimit()
+	url := fmt.Sprintf("%s/%s/%s", at.baseURL, db, table)
+	if recordID != "" {
+		url += fmt.Sprintf("/%s", recordID)
+	}
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return fmt.Errorf("cannot create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", at.apiKey))
+	req.URL.RawQuery = params.Encode()
+	err = at.do(req, url, target)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (at *Client) post(db, table string, data, response interface{}) error {
+	at.rateLimit()
+	url := fmt.Sprintf("%s/%s/%s", at.baseURL, db, table)
+	body, err := json.Marshal(data)
+	if err != nil {
+		return fmt.Errorf("cannot marshal body: %w", err)
+	}
+	req, err := http.NewRequest("POST", url, bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("cannot create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", at.apiKey))
+	return at.do(req, url, response)
+}
+
+func (at *Client) delete(db, table string, recordIDs []string, target interface{}) error {
+	at.rateLimit()
+	rawURL := fmt.Sprintf("%s/%s/%s", at.baseURL, db, table)
+	params := url.Values{}
+	for _, recordID := range recordIDs {
+		params.Set("records[]", recordID)
+	}
+	req, err := http.NewRequest("DELETE", rawURL, nil)
+	if err != nil {
+		return fmt.Errorf("cannot create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", at.apiKey))
+	req.URL.RawQuery = params.Encode()
+	err = at.do(req, rawURL, target)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (at *Client) patch(db, table, data, response interface{}) error {
+	at.rateLimit()
+	url := fmt.Sprintf("%s/%s/%s", at.baseURL, db, table)
+	body, err := json.Marshal(data)
+	if err != nil {
+		return fmt.Errorf("cannot marshal body: %w", err)
+	}
+	req, err := http.NewRequest("PATCH", url, bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("cannot create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", at.apiKey))
+	return at.do(req, url, response)
+}
+
+func (at *Client) do(req *http.Request, url string, response interface{}) error {
+	resp, err := at.client.Do(req)
+	if err != nil {
+		return fmt.Errorf("HTTP request failure on %s: %w", url, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode < 200 || resp.StatusCode > 299 {
+		return makeHTTPClientError(url, resp)
+	}
+	b, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("HTTP Read error on response for %s: %w", url, err)
+	}
+	err = json.Unmarshal(b, response)
+	if err != nil {
+		return fmt.Errorf("JSON decode failed on %s:\n%s\nerror: %w", url, string(b), err)
+	}
+	return nil
+}