add ocr

backend/internal/ocr/client.go

@@ -0,0 +1,91 @@
+package ocr
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+type Client struct {
+	endpoint   string
+	httpClient *http.Client
+}
+
+func NewClient(endpoint string) *Client {
+	return &Client{
+		endpoint: endpoint,
+		httpClient: &http.Client{
+			Timeout: 120 * time.Second,
+		},
+	}
+}
+
+func (c *Client) Recognize(imageData []byte) ([]TextBlock, error) {
+	b64 := base64.StdEncoding.EncodeToString(imageData)
+
+	reqBody, err := json.Marshal(OCRRequest{Image: b64})
+	if err != nil {
+		return nil, fmt.Errorf("marshal request: %w", err)
+	}
+
+	resp, err := c.httpClient.Post(
+		c.endpoint+"/ocr",
+		"application/json",
+		bytes.NewReader(reqBody),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("call paddleocr: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("paddleocr returned %d: %s", resp.StatusCode, string(body))
+	}
+
+	var ocrResp OCRResponse
+	if err := json.Unmarshal(body, &ocrResp); err != nil {
+		return nil, fmt.Errorf("decode response: %w", err)
+	}
+
+	if ocrResp.ErrorCode != 0 {
+		return nil, fmt.Errorf("paddleocr error %d: %s", ocrResp.ErrorCode, ocrResp.Message)
+	}
+
+	return flattenResults(ocrResp.Result), nil
+}
+
+func (c *Client) HealthCheck() error {
+	resp, err := c.httpClient.Get(c.endpoint + "/health")
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("health check failed: status %d", resp.StatusCode)
+	}
+	return nil
+}
+
+func flattenResults(result OCRResult) []TextBlock {
+	var blocks []TextBlock
+	for _, page := range result.OCRResults {
+		for i, text := range page.RecTexts {
+			score := 0.0
+			if i < len(page.RecScores) {
+				score = page.RecScores[i]
+			}
+			blocks = append(blocks, TextBlock{Text: text, Score: score})
+		}
+	}
+	return blocks
+}