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# GRID Stat Portal Project

### Project Overview
This is a web application for visualizing thousands of statistical indicators through interactive maps, charts, and data tables. Features include instant search, up-to-date values, and data downloads.

### Technical Stack
- Framework: Astro.js + React
- UI: Tailwind + shadcn/ui
- Data Visualization: D3.js
- Maps: 
  - d3-geo for projections and path generation
  - @fxi/d3-geo-zoom for interactive map navigation
- Search: Meilisearch
- Testing: Vitest

### Data Structure
- Indicators contain metadata and time series data. Example in ./sample/indicator_example.json
- Geographic Entities Mapping:
  - The TopoJSON world map uses ISO3 codes as feature IDs (d.id, not d.properties.id)
  - API returns geo_entity_id which is mapped to ISO3 using src/lib/utils/geo_entities.json
  - The geo_entities.json file contains a comprehensive mapping of all available codes
- Data includes measure_scale property for visualization type. Allowed measure scales are defined in src/lib/utils/visualization_scales.ts
- Temporal data spans multiple years. Tables aggregate data by geographic entities and display the oldest and most recent values

### API Information
1. Meilisearch:
   - Endpoint: https://api-search.unepgrid.ch
   - Index format: statistical_{language}
   - Facets: collections.name, keywords
   - Sample: sample/meilisearch_value_example.json

2. V2 API:
   - Endpoint: https://api.unepgrid.ch/stats/v2
   - Data endpoint: /indicators/{id}/data
   - Sample: ./sample/indicator_example.json


### Development Principles

#### Code Quality Standards
- Leverage existing D3 methods and functionality where available
- Follow functional programming principles for data transformations
- Ensure proper type safety and error handling
- Write comprehensive documentation for complex logic
- Use meaningful variable names and clear function signatures
- Implement proper unit tests for statistical functions


#### Known Issues
1. Proportional Symbol Issues:
   - Legend symbols do not match actual sizes on map