basic client

client.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	"golang.org/x/time/rate"
+)
+
+const baseURL = "https://api.solidarity.tech/v1"
+
+type Client struct {
+	key     string
+	dryRun  bool
+	http    *http.Client
+	limiter *rate.Limiter
+}
+
+func NewClient(key string, dryRun bool) *Client {
+	return &Client{
+		key:    key,
+		dryRun: dryRun,
+		http:   &http.Client{Timeout: 30 * time.Second},
+		// 60 requests per 30 seconds: 2/sec sustained, burst of 60.
+		limiter: rate.NewLimiter(2, 60),
+	}
+}
+
+// do applies the rate limit, retries once on 429, and returns the raw body.
+func (c *Client) do(ctx context.Context, method, path string, body io.Reader) ([]byte, error) {
+	if err := c.limiter.Wait(ctx); err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, method, baseURL+path, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Authorization", "Bearer "+c.key)
+	req.Header.Set("Accept", "application/json")
+	if body != nil {
+		req.Header.Set("Content-Type", "application/json")
+	}
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusTooManyRequests {
+		wait := 30 * time.Second
+		if s := resp.Header.Get("Retry-After"); s != "" {
+			if secs, err := strconv.Atoi(s); err == nil {
+				wait = time.Duration(secs) * time.Second
+			}
+		}
+		log.Printf("rate limited; waiting %s", wait)
+		select {
+		case <-time.After(wait):
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		}
+		return c.do(ctx, method, path, body)
+	}
+
+	raw, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode < 200 || resp.StatusCode > 299 {
+		return nil, fmt.Errorf("%s %s: %d: %s", method, path, resp.StatusCode, truncate(raw))
+	}
+	return raw, nil
+}
+
+func truncate(b []byte) string {
+	if len(b) > 300 {
+		return string(b[:300]) + "..."
+	}
+	return string(b)
+}

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/ncruces/go-strftime v1.0.0 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
 	golang.org/x/sys v0.47.0 // indirect
-	golang.org/x/time v0.15.0 // indirect
+	golang.org/x/time v0.16.0 // indirect
 	modernc.org/libc v1.75.6 // indirect
 	modernc.org/mathutil v1.7.1 // indirect
 	modernc.org/memory v1.12.1 // indirect

go.sum

@@ -12,6 +12,8 @@ golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
 golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
 golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
+golang.org/x/time v0.16.0 h1:vMb6ptszcQMkcwiRTAuNNU50gom6++Q/6gY2hDM6VDE=
+golang.org/x/time v0.16.0/go.mod h1:rVKOqvZeKvrDKTQiAHJ7wmwP0RzleSphoEA9RcdLA0s=
 modernc.org/libc v1.75.6 h1:yKk8qo+Di4gkmvRboK8ocCqH22FiUCR6jRy2OwtCRus=
 modernc.org/libc v1.75.6/go.mod h1:bO5o2ztHxBb2rjz0PgdHN0sSMw57CgxGFLZ3Qd/QpVQ=
 modernc.org/mathutil v1.7.1 h1:GCZVGXdaN8gTqB1Mf/usp1Y/hSqgI2vAGGP4jZMCxOU=

store.go

@@ -2,7 +2,8 @@ package main
 
 import (
 	"database/sql"
-	"log"
+	"errors"
+
 	"modernc.org/sqlite"
   sqlite3 "modernc.org/sqlite/lib"
 )