Add rowing machine endpoint

backend/handlers/handle_rowing.go

@@ -0,0 +1,154 @@
+package handlers
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/rwcarlsen/goexif/exif"
+
+	"adam-french.co.uk/backend/models"
+	"github.com/anthropics/anthropic-sdk-go"
+	"github.com/gin-gonic/gin"
+)
+
+type ExtractedRowingData struct {
+	TimeMinutes float64 `json:"timeMinutes"`
+	TimeSeconds float64 `json:"timeSeconds"`
+	Distance    float64 `json:"distance"`
+}
+
+func (store *Store) GetRowing(ctx *gin.Context) {
+	var rowing []models.Rowing
+	if err := store.DB.Order("Created_At DESC").Find(&rowing).Error; err != nil {
+		ctx.JSON(http.StatusInternalServerError, err.Error())
+		return
+	}
+	ctx.JSON(http.StatusOK, rowing)
+}
+
+func (store *Store) CreateRowing(ctx *gin.Context) {
+	file, err := ctx.FormFile("image")
+	if err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "image is required"})
+		return
+	}
+
+	f, err := file.Open()
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to open image"})
+		return
+	}
+	defer f.Close()
+
+	// Get the date taken from the EXIF data
+	x, err := exif.Decode(f)
+	if err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "no EXIF data found"})
+		return
+	}
+
+	dateTaken, err := x.DateTime()
+	if err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "no date found in EXIF data"})
+		return
+	}
+
+	// Seek back to start since exif.Decode advanced the cursor
+	if _, err := f.Seek(0, io.SeekStart); err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to seek image"})
+		return
+	}
+
+	data, err := io.ReadAll(f)
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to read image"})
+		return
+	}
+
+	allowedMediaTypes := map[string]bool{
+		"image/jpeg": true,
+		"image/png":  true,
+		"image/gif":  true,
+		"image/webp": true,
+	}
+	mediaType := file.Header.Get("Content-Type")
+	if !allowedMediaTypes[mediaType] {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "unsupported image type"})
+		return
+	}
+	encoded := base64.StdEncoding.EncodeToString(data)
+
+	// Build the message with an image + text prompt
+	message, err := store.ClaudeClient.Messages.New(context.Background(), anthropic.MessageNewParams{
+		Model:     anthropic.ModelClaudeHaiku4_5,
+		MaxTokens: 256,
+		Messages: []anthropic.MessageParam{
+			{
+				Role: "user",
+				Content: []anthropic.ContentBlockParamUnion{
+					// Image block
+					anthropic.NewImageBlock(anthropic.Base64ImageSourceParam{
+						Type:      "base64",
+						MediaType: anthropic.Base64ImageSourceMediaType(mediaType),
+						Data:      encoded,
+					}),
+					// Text prompt requesting exactly 2 variables
+					anthropic.NewTextBlock(
+						`Look at this rowing machine display. Extract the total elapsed time and total distance.
+
+Return ONLY a JSON object with these exact keys and numeric values:
+- "timeMinutes": total minutes (e.g. 2:30 = 2)
+- "timeSeconds": total seconds (e.g. 2:30 = 30)
+- "distance": distance in meters as a number (e.g. 5000)
+
+No text, no markdown, no explanation. Just the JSON object.`),
+				},
+			},
+		},
+	})
+
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to analyze image"})
+		return
+	}
+
+	if len(message.Content) == 0 {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "empty response from Claude"})
+		return
+	}
+
+	extractedData := ExtractedRowingData{}
+	err = json.Unmarshal([]byte(message.Content[0].Text), &extractedData)
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to parse JSON response"})
+		return
+	}
+
+	if extractedData.Distance == 0 {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid distance in image"})
+		return
+	}
+
+	totalSeconds := extractedData.TimeMinutes*60 + extractedData.TimeSeconds
+	totalDuration := time.Duration(totalSeconds * float64(time.Second))
+	per500m := time.Duration(totalSeconds / extractedData.Distance * 500 * float64(time.Second))
+
+	rowing := models.Rowing{
+		Date:        dateTaken,
+		Time:        totalDuration,
+		TimePer500m: per500m,
+		Distance:    extractedData.Distance,
+		Calories:    extractedData.Distance / 7500.0 * 500.0,
+	}
+
+	if err := store.DB.Create(&rowing).Error; err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to save rowing"})
+		return
+	}
+
+	ctx.JSON(http.StatusCreated, rowing)
+}