closedset

type Finding struct {
	// File and Line locate the finding: the migration that last defined the
	// CHECK when its list is wrong, the COMMENT ON CONSTRAINT otherwise.
	File string
	Line int
	// Table and Constraint name the CHECK as the migrations write them.
	Table, Constraint string
	// Set is the declared set's name, "" when the declaration names none.
	Set string
	// Problem is the sentence saying what is wrong.
	Problem string
	// Missing are the set's values the CHECK lacks; Extra the CHECK's values
	// the set lacks. Both empty unless the lists differ.
	Missing, Extra []string
	// Fix is the forward migration that repairs the finding, nil when there
	// is none forge can write (an unknown set, a CHECK it cannot read).
	Fix *Fix
}

type Fix struct {
	// BackwardCompatible is true when the fix only widens the CHECK: every
	// row the previous release wrote still satisfies it. Reason says why,
	// either way — the text of the migration's compatibility declaration.
	BackwardCompatible bool
	Reason             string
	// SQL is the migration body: the CHECK replaced whole, and the
	// declaration re-issued (postgres drops a constraint's comment with it).
	SQL string
	// Migration is the whole file, compatibility declaration first, ready to
	// paste into a new `forge db migration new` file.
	Migration string
}

type List struct {
	// Column is the column the list constrains, as postgres resolves it.
	Column string
	// Form is the SQL shape the list was read from: FormContainedBy,
	// FormAny or FormIn.
	Form string
	// Values are the list's members, in the order the CHECK spells them.
	Values []string
	// Start and End are the byte span, in the expression, that holds the
	// members (first member's start to last member's end, casts included).
	// Replacing it rewrites the list and leaves the rest of the expression —
	// `cardinality(scopes) > 0 AND …`, the trailing `::text[]` — verbatim.
	Start, End int
	// Cast is the per-member cast every member carries (`::text`,
	// `::character varying`), "" when the members carry none or differ. A
	// rewritten list repeats it, so a pg_dump-normalized CHECK stays in the
	// form pg_dump would write.
	Cast string
	// ArrayLiteral is set when the members came from one array-literal
	// string (`'{a,b}'::text[]`) rather than ARRAY[…] or a list; the span is
	// then the string literal itself.
	ArrayLiteral bool
	// Multiline is set when the CHECK puts its members on separate lines,
	// and Indent is the whitespace before the first one, so a rewritten
	// list keeps the layout.
	Multiline bool
	Indent    string
}

type Resolver func(name string) ([]string, error)

type Set struct {
	// Name is how a forge:closed-set declaration names it: the Go package
	// name and the variable, `accesstoken.AllScopes`.
	Name string
	// Values is the set's members, in the Go order — the order a fix
	// migration lists them in.
	Values []string
}