Refactor: reduce code duplication with shared abstractions

- Add BaseClient HTTP abstraction (internal/api/http.go) to eliminate
  duplicated HTTP boilerplate across Todoist, Trello, and PlanToEat clients
- Add response helpers (internal/handlers/response.go) for JSON/HTML responses
- Add generic cache wrapper (internal/handlers/cache.go) using Go generics
- Consolidate HandleCompleteAtom/HandleUncompleteAtom into handleAtomToggle
- Merge TabsHandler into Handler, delete tabs.go
- Extract sortTasksByUrgency and filterAndSortTrelloTasks helpers
- Update tests to work with new BaseClient structure

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 19 insertions, 48 deletions

diff --git a/internal/api/plantoeat.go b/internal/api/plantoeat.go
index 1dae246..eb29c63 100644
--- a/internal/api/plantoeat.go
+++ b/internal/api/plantoeat.go
@@ -2,35 +2,32 @@ package api
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
-	"io"
-	"net/http"
 	"time"
 
 	"task-dashboard/internal/models"
 )
 
-const (
-	planToEatBaseURL = "https://www.plantoeat.com/api/v2"
-)
+const planToEatBaseURL = "https://www.plantoeat.com/api/v2"
 
 // PlanToEatClient handles interactions with the PlanToEat API
 type PlanToEatClient struct {
-	apiKey     string
-	httpClient *http.Client
+	BaseClient
+	apiKey string
 }
 
 // NewPlanToEatClient creates a new PlanToEat API client
 func NewPlanToEatClient(apiKey string) *PlanToEatClient {
 	return &PlanToEatClient{
-		apiKey: apiKey,
-		httpClient: &http.Client{
-			Timeout: 15 * time.Second,
-		},
+		BaseClient: NewBaseClient(planToEatBaseURL),
+		apiKey:     apiKey,
 	}
 }
 
+func (c *PlanToEatClient) authHeaders() map[string]string {
+	return map[string]string{"Authorization": "Bearer " + c.apiKey}
+}
+
 // planToEatPlannerItem represents a planner item from the API
 type planToEatPlannerItem struct {
 	ID       int    `json:"id"`
@@ -51,59 +48,35 @@ type planToEatResponse struct {
 // GetUpcomingMeals fetches meals for the next N days
 func (c *PlanToEatClient) GetUpcomingMeals(ctx context.Context, days int) ([]models.Meal, error) {
 	if days <= 0 {
-		days = 7 // Default to 7 days
+		days = 7
 	}
 
 	startDate := time.Now()
 	endDate := startDate.AddDate(0, 0, days)
 
-	req, err := http.NewRequestWithContext(ctx, "GET", planToEatBaseURL+"/planner_items", nil)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create request: %w", err)
-	}
-
-	// Add query parameters
-	q := req.URL.Query()
-	q.Add("start_date", startDate.Format("2006-01-02"))
-	q.Add("end_date", endDate.Format("2006-01-02"))
-	req.URL.RawQuery = q.Encode()
-
-	// Add API key (check docs for correct header name)
-	req.Header.Set("Authorization", "Bearer "+c.apiKey)
-
-	resp, err := c.httpClient.Do(req)
-	if err != nil {
-		return nil, fmt.Errorf("failed to fetch meals: %w", err)
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != http.StatusOK {
-		body, _ := io.ReadAll(resp.Body)
-		return nil, fmt.Errorf("plantoeat API error (status %d): %s", resp.StatusCode, string(body))
-	}
+	path := fmt.Sprintf("/planner_items?start_date=%s&end_date=%s",
+		startDate.Format("2006-01-02"),
+		endDate.Format("2006-01-02"))
 
 	var apiResponse planToEatResponse
-	if err := json.NewDecoder(resp.Body).Decode(&apiResponse); err != nil {
-		return nil, fmt.Errorf("failed to decode response: %w", err)
+	if err := c.Get(ctx, path, c.authHeaders(), &apiResponse); err != nil {
+		return nil, fmt.Errorf("failed to fetch meals: %w", err)
 	}
 
-	// Convert to our model
 	meals := make([]models.Meal, 0, len(apiResponse.Items))
 	for _, item := range apiResponse.Items {
 		mealDate, err := time.Parse("2006-01-02", item.Date)
 		if err != nil {
-			continue // Skip invalid dates
+			continue
 		}
 
-		meal := models.Meal{
+		meals = append(meals, models.Meal{
 			ID:         fmt.Sprintf("%d", item.ID),
 			RecipeName: item.Recipe.Title,
 			Date:       mealDate,
 			MealType:   normalizeMealType(item.MealType),
 			RecipeURL:  item.Recipe.URL,
-		}
-
-		meals = append(meals, meal)
+		})
 	}
 
 	return meals, nil
@@ -121,18 +94,16 @@ func normalizeMealType(mealType string) string {
 	case "snack", "Snack":
 		return "snack"
 	default:
-		return "dinner" // Default to dinner
+		return "dinner"
 	}
 }
 
 // GetRecipes fetches recipes (for Phase 2)
 func (c *PlanToEatClient) GetRecipes(ctx context.Context) error {
-	// This will be implemented in Phase 2
 	return fmt.Errorf("not implemented yet")
 }
 
 // AddMealToPlanner adds a meal to the planner (for Phase 2)
 func (c *PlanToEatClient) AddMealToPlanner(ctx context.Context, recipeID string, date time.Time, mealType string) error {
-	// This will be implemented in Phase 2
 	return fmt.Errorf("not implemented yet")
 }