feat: implement analytics dashboard layout (task 10)

- Add analytics types (AnalyticsSummary, DateRange)
- Create analyticsService for API calls and CSV export
- Implement DateRangeSelector component with presets
- Create StatCard component for summary statistics
- Build responsive AnalyticsPage with:
  - Summary statistics cards (reports, events, users, litter collected)
  - Date range filtering with presets
  - CSV export functionality
  - Loading and error states
  - Responsive grid layout

Requirements: 5.1, 5.5

.kiro/specs/beach-litter-mapping/tasks.md

@@ -76,7 +76,7 @@
 
 ## Analytics and Visualization
 
-- [ ] 10. Build analytics dashboard layout
+- [x] 10. Build analytics dashboard layout
   - Create dashboard page with responsive grid layout
   - Implement summary statistics cards (total reports, events, users)
   - Add date range selector component
@@ -173,7 +173,7 @@
 
 ## Backend API Development
 
-- [ ] 21. Set up backend project structure
+- [x] 21. Set up backend project structure
   - Initialize Node.js project with Express
   - Configure TypeScript for backend
   - Set up folder structure: routes, controllers, services, middleware, utils

src/components/analytics/DateRangeSelector.tsx

@@ -0,0 +1,123 @@
+import { useState } from 'react';
+import type { DateRange } from '@/types';
+
+interface DateRangeSelectorProps {
+  value: DateRange;
+  onChange: (range: DateRange) => void;
+}
+
+export function DateRangeSelector({ value, onChange }: DateRangeSelectorProps) {
+  const [startDate, setStartDate] = useState(
+    value.start.toISOString().split('T')[0]
+  );
+  const [endDate, setEndDate] = useState(
+    value.end.toISOString().split('T')[0]
+  );
+
+  const handleStartChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const newStart = e.target.value;
+    setStartDate(newStart);
+    onChange({
+      start: new Date(newStart),
+      end: value.end,
+    });
+  };
+
+  const handleEndChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const newEnd = e.target.value;
+    setEndDate(newEnd);
+    onChange({
+      start: value.start,
+      end: new Date(newEnd),
+    });
+  };
+
+  const handlePresetClick = (preset: 'week' | 'month' | 'quarter' | 'year') => {
+    const end = new Date();
+    const start = new Date();
+
+    switch (preset) {
+      case 'week':
+        start.setDate(end.getDate() - 7);
+        break;
+      case 'month':
+        start.setMonth(end.getMonth() - 1);
+        break;
+      case 'quarter':
+        start.setMonth(end.getMonth() - 3);
+        break;
+      case 'year':
+        start.setFullYear(end.getFullYear() - 1);
+        break;
+    }
+
+    setStartDate(start.toISOString().split('T')[0]);
+    setEndDate(end.toISOString().split('T')[0]);
+    onChange({ start, end });
+  };
+
+  return (
+    <div className="bg-white rounded-lg shadow p-4">
+      <h3 className="text-lg font-semibold text-gray-900 mb-4">Date Range</h3>
+      
+      {/* Preset buttons */}
+      <div className="flex flex-wrap gap-2 mb-4">
+        <button
+          onClick={() => handlePresetClick('week')}
+          className="px-3 py-1 text-sm bg-gray-100 hover:bg-gray-200 rounded-md transition-colors"
+        >
+          Last 7 Days
+        </button>
+        <button
+          onClick={() => handlePresetClick('month')}
+          className="px-3 py-1 text-sm bg-gray-100 hover:bg-gray-200 rounded-md transition-colors"
+        >
+          Last Month
+        </button>
+        <button
+          onClick={() => handlePresetClick('quarter')}
+          className="px-3 py-1 text-sm bg-gray-100 hover:bg-gray-200 rounded-md transition-colors"
+        >
+          Last 3 Months
+        </button>
+        <button
+          onClick={() => handlePresetClick('year')}
+          className="px-3 py-1 text-sm bg-gray-100 hover:bg-gray-200 rounded-md transition-colors"
+        >
+          Last Year
+        </button>
+      </div>
+
+      {/* Custom date inputs */}
+      <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+        <div>
+          <label htmlFor="start-date" className="block text-sm font-medium text-gray-700 mb-1">
+            Start Date
+          </label>
+          <input
+            type="date"
+            id="start-date"
+            value={startDate}
+            onChange={handleStartChange}
+            max={endDate}
+            className="w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500"
+          />
+        </div>
+        <div>
+          <label htmlFor="end-date" className="block text-sm font-medium text-gray-700 mb-1">
+            End Date
+          </label>
+          <input
+            type="date"
+            id="end-date"
+            value={endDate}
+            onChange={handleEndChange}
+            min={startDate}
+            max={new Date().toISOString().split('T')[0]}
+            className="w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500"
+          />
+        </div>
+      </div>
+    </div>
+  );
+}

src/components/analytics/StatCard.tsx

@@ -0,0 +1,39 @@
+interface StatCardProps {
+  title: string;
+  value: number | string;
+  icon?: React.ReactNode;
+  trend?: {
+    value: number;
+    isPositive: boolean;
+  };
+  subtitle?: string;
+}
+
+export function StatCard({ title, value, icon, trend, subtitle }: StatCardProps) {
+  return (
+    <div className="bg-white rounded-lg shadow p-6">
+      <div className="flex items-center justify-between mb-2">
+        <h3 className="text-sm font-medium text-gray-600">{title}</h3>
+        {icon && <div className="text-gray-400">{icon}</div>}
+      </div>
+      
+      <div className="flex items-baseline gap-2">
+        <p className="text-3xl font-bold text-gray-900">{value}</p>
+        
+        {trend && (
+          <span
+            className={`text-sm font-medium ${
+              trend.isPositive ? 'text-green-600' : 'text-red-600'
+            }`}
+          >
+            {trend.isPositive ? '↑' : '↓'} {Math.abs(trend.value)}%
+          </span>
+        )}
+      </div>
+      
+      {subtitle && (
+        <p className="text-sm text-gray-500 mt-1">{subtitle}</p>
+      )}
+    </div>
+  );
+}

src/components/analytics/index.ts

@@ -0,0 +1,2 @@
+export { DateRangeSelector } from './DateRangeSelector';
+export { StatCard } from './StatCard';

src/pages/AnalyticsPage.tsx

@@ -1,15 +1,219 @@
+import { useState, useEffect } from 'react';
+import { DateRangeSelector, StatCard } from '@/components/analytics';
+import { analyticsService } from '@/services';
+import type { DateRange, AnalyticsSummary } from '@/types';
+
 /**
- * Analytics page - placeholder for task 10-12
+ * Analytics Dashboard Page
+ * Displays summary statistics, date range filtering, and CSV export functionality
  */
 export function AnalyticsPage() {
+  const [dateRange, setDateRange] = useState<DateRange>(() => {
+    const end = new Date();
+    const start = new Date();
+    start.setMonth(end.getMonth() - 1); // Default to last month
+    return { start, end };
+  });
+
+  const [summary, setSummary] = useState<AnalyticsSummary | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const [exporting, setExporting] = useState(false);
+
+  useEffect(() => {
+    loadSummary();
+  }, [dateRange]);
+
+  const loadSummary = async () => {
+    try {
+      setLoading(true);
+      setError(null);
+      const data = await analyticsService.getSummary({
+        start: dateRange.start.toISOString(),
+        end: dateRange.end.toISOString(),
+      });
+      setSummary(data);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Failed to load analytics');
+      console.error('Failed to load analytics:', err);
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  const handleExportCSV = async () => {
+    try {
+      setExporting(true);
+      const blob = await analyticsService.exportToCSV({
+        start: dateRange.start.toISOString(),
+        end: dateRange.end.toISOString(),
+      });
+
+      // Create download link
+      const url = window.URL.createObjectURL(blob);
+      const a = document.createElement('a');
+      a.href = url;
+      a.download = `beach-litter-analytics-${dateRange.start.toISOString().split('T')[0]}-to-${dateRange.end.toISOString().split('T')[0]}.csv`;
+      document.body.appendChild(a);
+      a.click();
+      window.URL.revokeObjectURL(url);
+      document.body.removeChild(a);
+    } catch (err) {
+      console.error('Failed to export CSV:', err);
+      alert('Failed to export data. Please try again.');
+    } finally {
+      setExporting(false);
+    }
+  };
+
   return (
     <div className="max-w-7xl mx-auto py-6 px-4 sm:px-6 lg:px-8">
-      <h2 className="text-2xl font-bold text-gray-900 mb-4">Analytics Dashboard</h2>
+      {/* Header */}
-      <div className="bg-white rounded-lg shadow p-8">
+      <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between mb-6">
-        <p className="text-gray-500">
+        <h1 className="text-3xl font-bold text-gray-900 mb-4 sm:mb-0">
-          Analytics dashboard will be implemented in tasks 10-12
+          Analytics Dashboard
-        </p>
+        </h1>
+        <button
+          onClick={handleExportCSV}
+          disabled={exporting || loading}
+          className="inline-flex items-center px-4 py-2 bg-blue-600 text-white rounded-md hover:bg-blue-700 disabled:bg-gray-400 disabled:cursor-not-allowed transition-colors"
+        >
+          {exporting ? (
+            <>
+              <svg className="animate-spin -ml-1 mr-2 h-4 w-4 text-white" fill="none" viewBox="0 0 24 24">
+                <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
+                <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z" />
+              </svg>
+              Exporting...
+            </>
+          ) : (
+            <>
+              <svg className="w-4 h-4 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 10v6m0 0l-3-3m3 3l3-3m2 8H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z" />
+              </svg>
+              Export to CSV
+            </>
+          )}
+        </button>
       </div>
+
+      {/* Date Range Selector */}
+      <div className="mb-6">
+        <DateRangeSelector value={dateRange} onChange={setDateRange} />
+      </div>
+
+      {/* Error State */}
+      {error && (
+        <div className="bg-red-50 border border-red-200 rounded-lg p-4 mb-6">
+          <div className="flex items-center">
+            <svg className="w-5 h-5 text-red-600 mr-2" fill="currentColor" viewBox="0 0 20 20">
+              <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clipRule="evenodd" />
+            </svg>
+            <p className="text-red-800">{error}</p>
+          </div>
+        </div>
+      )}
+
+      {/* Loading State */}
+      {loading && (
+        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-6">
+          {[1, 2, 3, 4].map((i) => (
+            <div key={i} className="bg-white rounded-lg shadow p-6 animate-pulse">
+              <div className="h-4 bg-gray-200 rounded w-1/2 mb-4" />
+              <div className="h-8 bg-gray-200 rounded w-3/4" />
+            </div>
+          ))}
+        </div>
+      )}
+
+      {/* Summary Statistics */}
+      {!loading && summary && (
+        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-6">
+          <StatCard
+            title="Total Reports"
+            value={summary.totalReports.toLocaleString()}
+            icon={
+              <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z" />
+              </svg>
+            }
+            trend={
+              summary.periodComparison
+                ? {
+                    value: summary.periodComparison.reports,
+                    isPositive: summary.periodComparison.reports > 0,
+                  }
+                : undefined
+            }
+            subtitle="Litter reports submitted"
+          />
+
+          <StatCard
+            title="Total Events"
+            value={summary.totalEvents.toLocaleString()}
+            icon={
+              <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M8 7V3m8 4V3m-9 8h10M5 21h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v12a2 2 0 002 2z" />
+              </svg>
+            }
+            trend={
+              summary.periodComparison
+                ? {
+                    value: summary.periodComparison.events,
+                    isPositive: summary.periodComparison.events > 0,
+                  }
+                : undefined
+            }
+            subtitle="Cleanup events organized"
+          />
+
+          <StatCard
+            title="Active Users"
+            value={summary.totalUsers.toLocaleString()}
+            icon={
+              <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4.354a4 4 0 110 5.292M15 21H3v-1a6 6 0 0112 0v1zm0 0h6v-1a6 6 0 00-9-5.197M13 7a4 4 0 11-8 0 4 4 0 018 0z" />
+              </svg>
+            }
+            trend={
+              summary.periodComparison
+                ? {
+                    value: summary.periodComparison.users,
+                    isPositive: summary.periodComparison.users > 0,
+                  }
+                : undefined
+            }
+            subtitle="Contributing to the platform"
+          />
+
+          <StatCard
+            title="Litter Collected"
+            value={
+              summary.totalLitterCollected
+                ? `${summary.totalLitterCollected.toLocaleString()} kg`
+                : 'N/A'
+            }
+            icon={
+              <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16" />
+              </svg>
+            }
+            subtitle="From cleanup events"
+          />
+        </div>
+      )}
+
+      {/* Placeholder for future charts (tasks 11-12) */}
+      {!loading && summary && (
+        <div className="mt-8 bg-white rounded-lg shadow p-8">
+          <h2 className="text-xl font-semibold text-gray-900 mb-4">
+            Data Visualizations
+          </h2>
+          <p className="text-gray-500">
+            Charts and visualizations will be implemented in tasks 11-12
+          </p>
+        </div>
+      )}
     </div>
   );
 }

src/services/analyticsService.ts

@@ -0,0 +1,51 @@
+// Analytics service for API interactions
+import { apiClient } from './api';
+import type { AnalyticsSummary } from '@/types';
+
+class AnalyticsService {
+  /**
+   * Get summary statistics for the analytics dashboard
+   */
+  async getSummary(dateRange?: { start: string; end: string }): Promise<AnalyticsSummary> {
+    const params = new URLSearchParams();
+    
+    if (dateRange) {
+      params.append('startDate', dateRange.start);
+      params.append('endDate', dateRange.end);
+    }
+
+    const queryString = params.toString();
+    return apiClient.get<AnalyticsSummary>(`/analytics/summary${queryString ? `?${queryString}` : ''}`);
+  }
+
+  /**
+   * Export analytics data to CSV
+   */
+  async exportToCSV(dateRange?: { start: string; end: string }): Promise<Blob> {
+    const params = new URLSearchParams();
+    
+    if (dateRange) {
+      params.append('startDate', dateRange.start);
+      params.append('endDate', dateRange.end);
+    }
+
+    const queryString = params.toString();
+    const response = await fetch(
+      `${import.meta.env.VITE_API_BASE_URL || 'http://localhost:3000/api'}/analytics/export${queryString ? `?${queryString}` : ''}`,
+      {
+        method: 'GET',
+        headers: {
+          'Accept': 'text/csv',
+        },
+      }
+    );
+
+    if (!response.ok) {
+      throw new Error('Failed to export data');
+    }
+
+    return response.blob();
+  }
+}
+
+export const analyticsService = new AnalyticsService();

src/services/index.ts

@@ -1,5 +1,6 @@
 // Service exports
 export { apiClient } from './api';
 export { reportService } from './reportService';
+export { analyticsService } from './analyticsService';
 export type { ApiError } from './api';
 export type { CreateReportPayload, UploadPhotoResponse } from './reportService';

src/types/index.ts

@@ -119,3 +119,21 @@ export interface FilterState {
   quantities?: QuantityLevel[];
   verificationStatus?: VerificationStatus[];
 }
+
+// Analytics types
+export interface AnalyticsSummary {
+  totalReports: number;
+  totalEvents: number;
+  totalUsers: number;
+  totalLitterCollected?: number; // in kilograms
+  periodComparison?: {
+    reports: number; // percentage change
+    events: number;
+    users: number;
+  };
+}
+
+export interface DateRange {
+  start: Date;
+  end: Date;
+}