// Package sql defines reusable database SQL statements.
package sql

const (
	// ParameterComponentQueryBase selects the component owning a parameter and
	// joins its complete hierarchy so seven-part tokens can be validated as one path.
	ParameterComponentQueryBase = `SELECT c.*
		FROM component AS c
		INNER JOIN station AS s ON s.id = c.station_id
		INNER JOIN zone AS z ON z.id = s.zone_id
		INNER JOIN grid AS g ON g.id = z.grid_id`

	// ParameterSevenPartTokenWhere matches the complete parameter token prefix
	// token1.token2.token3.token4.token5.
	ParameterSevenPartTokenWhere = `WHERE g.tagname = ?
		AND z.tagname = ?
		AND s.tagname = ?
		AND c.nspath = ?
		AND c.tag = ?`

	// ParameterFourPartTokenWhere matches token4.token5 and restricts the short
	// token form to components belonging to a local station.
	ParameterFourPartTokenWhere = `WHERE c.nspath = ?
		AND c.tag = ?
		AND s.is_local = TRUE`

	// ParameterLimitTwo allows callers to distinguish a unique component from
	// an ambiguous token without loading every matching row.
	ParameterLimitTwo = `LIMIT 2`

	// ParameterAttributeColumnType checks that token7 is an actual column of
	// the dynamic parameter table and returns its PostgreSQL display type.
	ParameterAttributeColumnType = `SELECT pg_catalog.format_type(a.atttypid, a.atttypmod)
		FROM pg_catalog.pg_attribute AS a
		INNER JOIN pg_catalog.pg_class AS c ON c.oid = a.attrelid
		INNER JOIN pg_catalog.pg_namespace AS n ON n.oid = c.relnamespace
		WHERE n.nspname = 'public'
		AND c.relname = ?
		AND a.attname = ?
		AND a.attnum > 0
		AND NOT a.attisdropped
		LIMIT 1`

	// ParameterAttributeDescription returns the display name of token7 from the
	// basic attribute metadata table. Two rows are enough to detect ambiguity.
	ParameterAttributeDescription = `SELECT attribute_name
		FROM basic.attribute
		WHERE attribute = ?
		LIMIT 2`
)