package textfmt

import "fmt"

type escapeRange struct {
	from, to    rune
	replacement string
}

type escape[S any] struct {
	out               writer
	state             S
	escape            map[rune]string
	escapeRanges      []escapeRange
	conditionalEscape map[rune]func(S, rune) (string, bool)
	updateState       func(S, rune) S
}

func (e *escape[S]) inEscapeRange(r rune) (string, bool) {
	for _, rng := range e.escapeRanges {
		if r >= rng.from && r <= rng.to {
			return rng.replacement, true
		}
	}

	return "", false
}

func (e *escape[S]) write(a ...any) {
	for _, ai := range a {
		s := fmt.Sprint(ai)
		r := []rune(s)
		for _, ri := range r {
			var (
				output string
				found  bool
			)

			output, found = e.escape[ri]
			if !found {
				output, found = e.inEscapeRange(ri)
			}

			if !found {
				conditional := e.conditionalEscape[ri]
				if conditional != nil {
					output, found = conditional(e.state, ri)
				}
			}

			if !found {
				output = string(ri)
			}

			e.out.write(output)
			if e.updateState != nil {
				e.state = e.updateState(e.state, ri)
			}
		}
	}
}

func (e *escape[S]) flush() {
	e.out.flush()
}

func (e *escape[S]) error() error {
	return e.out.error()
}

func (e *escape[S]) setErr(err error) {
}