feat: Integrate PapaParse for CSV handling

Adds papaparse as a dependency and updates the data processing service to use it for more robust CSV file parsing. This replaces manual CSV parsing logic with a dedicated library, improving reliability and handling of various CSV formats.

Also renames the `MoversIcon` to `TrendingIcon` to better reflect its usage in indicating trending performance metrics.

services/geminiService.ts

@@ -2,39 +2,49 @@
 import { GoogleGenAI } from "@google/genai";
 import { AggregatedData } from "../types";
 
+// Declare process to avoid TypeScript errors without causing aggressive bundler shims
+declare const process: any;
+
 const SYSTEM_INSTRUCTION = `
-You are an expert Data Analyst Assistant for "Craze Analytix".
-You have access to a structured dataset of sales performance including Revenue (Sell Out), Units, Product Lines, and Seasonality.
+You are a senior data analyst assistant for a retail dashboard called "Craze Analytix".
+You have access to a detailed report of the currently filtered sales data.
+The data includes Sell Out (Revenue in €), Units Sold, Product Lines, Customers/Markets, and Seasonality trends.
 
-Your Capabilities:
-1. **Analyze Trends**: Use the provided Seasonality and Yearly Breakdown data.
-2. **Perform Calculations**: You have access to detailed Product Line totals. You MUST calculate growth percentages, market shares, and sums dynamically if the user asks.
-3. **Compare**: Compare performance between years (e.g., 2024 vs 2025).
-
-Rules:
-- If the user asks for a calculation (e.g., "What is the % share of Line X?"), perform the math using the provided numbers.
-- Always format currency as € (e.g., €1,200) and units with 'u' or 'units' (e.g., 500 units).
-- Be concise but insightful. Point out significant growth or decline.
-- If data is missing for a specific query, state clearly that it is not in the current filtered view.
+Your goal is to answer user questions specific to the provided data.
+- If asked about "Trends" or "Seasonality", look at the Monthly Seasonality section.
+- If asked about "Growth" or "Decline", look at the Top/Bottom Movers sections.
+- If asked about specific Product Lines, look at the Product Line Breakdown.
+- Always format numbers clearly (e.g., "€1.2M", "€5,200", "15k units").
+- When comparing years, calculate the percentage difference if not explicitly provided.
+- Keep answers professional, concise, and business-focused.
 `;
 
+// Helper to get API key safely
+const getApiKey = (): string | undefined => {
+  try {
+    return process.env.API_KEY;
+  } catch (e) {
+    return undefined;
+  }
+};
+
 const formatCurrency = (val: number) => `€${val.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0})}`;
 const formatUnits = (val: number) => `${val.toLocaleString()} units`;
 
 export const queryGemini = async (
-  apiKey: string,
   question: string, 
   context: AggregatedData, 
   filteredRecordCount: number
 ): Promise<string> => {
   
+  const apiKey = getApiKey();
+
   if (!apiKey) {
-    return "Please provide your Gemini API Key in the settings to enable the AI assistant.";
+    return "API Key is missing. Please configure your environment variables (API_KEY) or check your .env file.";
   }
 
   try {
-    // Ensure the key is clean of whitespace
-    const ai = new GoogleGenAI({ apiKey: apiKey.trim() });
+    const ai = new GoogleGenAI({ apiKey });
 
     // --- CONTEXT GENERATION ---
     // We construct a structured report mirroring the dashboard charts
@@ -46,62 +56,64 @@ export const queryGemini = async (
         .join('\n');
 
     // 2. Seasonality (Line Chart Data)
+    // We simplify this to a CSV-like list for the AI to parse trends
     const seasonalitySummary = context.seasonality.map(p => {
+        // Extract values for each year in the point
         const yearValues = context.availableYears.map(y => `${y}: ${formatCurrency(p[y] as number || 0)}`).join(', ');
         return `  - ${p.name}: [${yearValues}]`;
     }).join('\n');
 
-    // 3. Growth/Decline
+    // 3. Top Movers (Growth Table) - Limit to Top 10
     const growthSummary = context.topMovers.slice(0, 10).map(m => 
         `  - ${m.line}: +€${m.sellOutGrowthValue.toLocaleString()} (${m.sellOutGrowthPercentage.toFixed(1)}%)`
     ).join('\n');
 
+    // 4. Declining Movers (Decline Table) - Limit to Top 10
     const declineSummary = context.bottomMovers.slice(0, 10).map(m => 
         `  - ${m.line}: -€${Math.abs(m.sellOutGrowthValue).toLocaleString()} (${m.sellOutGrowthPercentage.toFixed(1)}%)`
     ).join('\n');
 
-    // 4. DETAILED BREAKDOWN (For Calculations)
-    // We provide a JSON-like structure of ALL top product lines so the AI can compute shares/totals.
-    // We limit this to top 100 to avoid token limits, which covers most relevant data.
-    const detailedLines = context.byLine.slice(0, 100).map(l => ({
-        name: l.name,
-        revenue: l.value,
-        units: l.units
-    }));
+    // 5. Product Lines Overview (Bar Charts) - Limit to Top 50 to save tokens but give depth
+    const topLinesSummary = context.byLine.slice(0, 50).map((l, i) => 
+        `  ${i+1}. ${l.name}: ${formatCurrency(l.value)} | ${formatUnits(l.units)}`
+    ).join('\n');
+
+    // 6. Customer Distribution (Customer Chart)
+    const customerSummary = context.byCustomer.map(c => 
+        `  - ${c.name}: ${formatCurrency(c.value)}`
+    ).join('\n');
 
     const fullReport = `
-REPORT CONTEXT (Based on Current Filters):
-------------------------------------------
-GLOBAL METRICS:
+REPORT CONTEXT:
+----------------
+GLOBAL TOTALS:
 Total Sell Out: ${formatCurrency(context.totalSellOut)}
 Total Units: ${formatUnits(context.totalUnits)}
 Records Analyzed: ${filteredRecordCount}
 Years Available: ${context.availableYears.join(', ')}
 
-YEARLY TOTALS:
+YEARLY BREAKDOWN:
 ${yearlySummary}
 
-MONTHLY TRENDS (Seasonality):
+MONTHLY SEASONALITY (Revenue Trends):
 ${seasonalitySummary}
 
-TOP PERFORMERS (Growth YoY):
+FASTEST GROWING LINES (Year-over-Year):
 ${growthSummary}
 
-WORST PERFORMERS (Decline YoY):
+DECLINING LINES (Year-over-Year):
 ${declineSummary}
 
-DETAILED PRODUCT LINE DATA (Use this for specific calculations):
-${JSON.stringify(detailedLines, null, 2)}
+TOP PRODUCT LINES (Revenue & Units):
+${topLinesSummary}
+
+PERFORMANCE BY CUSTOMER:
+${customerSummary}
 `;
 
     const response = await ai.models.generateContent({
-      model: 'gemini-3-pro-preview', // Updated to the latest capable model for complex reasoning
-      contents: [
-        {
-          role: 'user',
-          parts: [{ text: `Context Data:\n${fullReport}\n\nUser Question: ${question}` }]
-        }
-      ],
+      model: 'gemini-2.5-flash',
+      contents: `Context Data:\n${fullReport}\n\nUser Question: ${question}`,
       config: {
         systemInstruction: SYSTEM_INSTRUCTION,
       }
@@ -111,11 +123,8 @@ ${JSON.stringify(detailedLines, null, 2)}
   } catch (error: any) {
     console.error("Gemini API Error:", error);
     
-    if (error.message && error.message.includes("403")) {
-       return "Error 403: Invalid API Key. Please check your key in the settings.";
-    }
-    if (error.message && error.message.includes("429")) {
-        return "Error 429: Quota exceeded. You are sending too many requests.";
+    if (error.message && error.message.includes("Not implemented on this platform")) {
+       return "System Error: The AI SDK detected a platform mismatch.";
     }
 
     return `Error: ${error.message || "An unexpected error occurred while analyzing the data."}`;