package textedit

func sequenceEdit(e []Editor) func(rune, []any) ([]rune, []any) {
	return func(r rune, s []any) ([]rune, []any) {
		var sr []any
		rr := []rune{r}
		for i, ei := range e {
			var si any
			if len(s) > i {
				si = s[i]
			}

			rin := rr
			rr = nil
			for _, ri := range rin {
				var rout []rune
				rout, si = ei.Edit(ri, si)
				rr = append(rr, rout...)
			}

			sr = append(sr, si)
		}

		return rr, sr
	}
}

func sequenceRelease(e []Editor) func([]any) []rune {
	return func(s []any) []rune {
		var rr []rune
		for i, ei := range e {
			var r []rune
			if i < len(s) {
				r = ei.ReleaseState(s[i])
			}

			for _, ri := range r {
				var (
					rri []rune
					ssi []any
				)

				if i < len(s) {
					ssi = s[i:]
				}

				rri, ssi = sequenceEdit(e[i+1:])(ri, ssi)
				rr = append(rr, rri...)
				if i < len(s) {
					s = append(s[:i], ssi...)
				}
			}
		}

		return rr
	}
}

func sequence(e ...Editor) Editor {
	init := make([]any, len(e))
	for i, ei := range e {
		if initializer, ok := ei.(interface{ initialize() any }); ok {
			init[i] = initializer.initialize()
		}
	}

	return FuncInit(
		sequenceEdit(e),
		sequenceRelease(e),
		init,
	)
}