package server

import "sync"

// TileCache is a thread-safe in-memory cache for rendered PNG tiles.
// Keys are "z/x/y". The entire cache is invalidated on each new radar scan.
type TileCache struct {
	mu    sync.RWMutex
	tiles map[string][]byte
}

func NewTileCache() *TileCache {
	return &TileCache{tiles: make(map[string][]byte)}
}

func (c *TileCache) Get(key string) ([]byte, bool) {
	c.mu.RLock()
	defer c.mu.RUnlock()
	v, ok := c.tiles[key]
	return v, ok
}

func (c *TileCache) Set(key string, data []byte) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.tiles[key] = data
}

// Invalidate clears all cached tiles. Call this after each new radar product is loaded.
func (c *TileCache) Invalidate() {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.tiles = make(map[string][]byte)
}