function extract_static_fields(symbols, site) {
	const site_fields = []
	const site_entries = []
	
	const symbol_fields = []
	const symbol_entries = []

	for (const symbol of symbols) {
		// const symbol_fields = flatten_fields(symbol.fields.filter(s => s.is_static))
		const all_entries = flatten_content(symbol.content, symbol.fields)
		for (const field of symbol.fields.filter(s => s.is_static)) {

			// move symbol field to site
			const root_site_field = { ...Field({ ...field, type: field.type, site: site.id }), id: field.id }
			const child_site_fields = flatten_fields(field.fields, root_site_field.id)
			site_fields.push(root_site_field, ...child_site_fields)

			// move symbol entries to field
			const root_entry = all_entries.find(e => e.field === root_site_field.id)
			const child_entries = all_entries.filter(entry => {
				const belongs_to_field = child_site_fields.some(f => f.id === entry.field) || entry.parent === root_entry.id // repeater containers
				return belongs_to_field 
			})
			site_entries.push(root_entry, ...child_entries)

			// create symbol 'site-field' field
			const symbol_field = Field({ ...field, symbol: symbol.id, type: 'site-field', source: root_site_field.id })
			symbol_fields.push(symbol_field)

			// create symbol 'site-field' entry
			const symbol_entry = Content_Row({ field: symbol_field.id })
			symbol_entries.push(symbol_entry)
		}
	}

	return {
		site: {
			fields: site_fields,
			entries: site_entries
		},
		symbol: {
			fields: symbol_fields,
			entries: symbol_entries
		}
	}
}
@returns {{ site: { fields: Array<import('$lib').Field>, entries: Array<import('$lib').Entry>}, symbol: { fields: Array<import('$lib').Field>, entries: Array<import('$lib').Entry>}}}