UPDATE: Add raster tiles

internal/repositories/rasterTileRepository.go

@@ -0,0 +1,99 @@
+package repositories
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"history-api/pkg/cache"
+	"history-api/pkg/constants"
+	"time"
+)
+
+type RasterTileRepository interface {
+	GetMetadata(ctx context.Context) (map[string]string, error)
+	GetTile(ctx context.Context, z, x, y int) ([]byte, string, error)
+}
+
+type rasterTileRepository struct {
+	db *sql.DB
+	c  cache.Cache
+}
+
+func NewRasterTileRepository(db *sql.DB, c cache.Cache) RasterTileRepository {
+	return &rasterTileRepository{
+		db: db,
+		c:  c,
+	}
+}
+
+func (r *rasterTileRepository) GetMetadata(ctx context.Context) (map[string]string, error) {
+	cacheId := "rasterTile:metadata"
+
+	var cached map[string]string
+	err := r.c.Get(ctx, cacheId, &cached)
+	if err == nil {
+		return cached, nil
+	}
+
+	rows, err := r.db.QueryContext(ctx, "SELECT name, value FROM metadata")
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	metadata := make(map[string]string)
+
+	for rows.Next() {
+		var name, value string
+		if err := rows.Scan(&name, &value); err != nil {
+			return nil, err
+		}
+		metadata[name] = value
+	}
+
+	_ = r.c.Set(ctx, cacheId, metadata, constants.NormalCacheDuration)
+
+	return metadata, nil
+}
+
+func (r *rasterTileRepository) GetTile(ctx context.Context, z, x, y int) ([]byte, string, error) {
+	if z < 0 || x < 0 || y < 0 {
+		return nil, "", fmt.Errorf("invalid tile coordinates")
+	}
+
+	// cache key
+	cacheId := fmt.Sprintf("rasterTile:%d:%d:%d", z, x, y)
+
+	var cached []byte
+	err := r.c.Get(ctx, cacheId, &cached)
+	if err == nil {
+		meta, _ := r.GetMetadata(ctx)
+		return cached, meta["format"], nil
+	}
+
+	// XYZ -> TMS
+	tmsY := (1 << z) - 1 - y
+
+	var tileData []byte
+
+	err = r.db.QueryRowContext(ctx, `
+        SELECT tile_data
+        FROM tiles
+        WHERE zoom_level = ?
+          AND tile_column = ?
+          AND tile_row = ?
+    `, z, x, tmsY).Scan(&tileData)
+
+	if err != nil {
+		return nil, "", err
+	}
+
+	meta, err := r.GetMetadata(ctx)
+	if err != nil {
+		return nil, "", err
+	}
+
+	_ = r.c.Set(ctx, cacheId, tileData, 5*time.Minute)
+
+	return tileData, meta["format"], nil
+}