package basic

import (
	"bytes"
	"io"
	"io/fs"
	"log"
	"strings"

	"asciigoat.org/core/lexer"
	"asciigoat.org/ini/parser"
)

type token struct {
	pos   lexer.Position
	typ   parser.TokenType
	value string
}

type decoder struct {
	p   *parser.Parser
	out *Document

	queue      []token
	curSection *Section
	curField   *Field
}

func (dec *decoder) OnToken(pos lexer.Position, typ parser.TokenType, value string) error {
	tok := token{pos, typ, value}

	log.Printf("%s[%v]: %s %s: %q", "decoder", len(dec.queue), pos, typ, value)

	dec.queue = append(dec.queue, tok)

	return nil
}

func (*decoder) OnError(pos lexer.Position, hint string, err error) error {
	log.Printf("%s: %s %s: %s: %v", "decoder", pos, "error", hint, err)
	return err
}

// Decode ...
func Decode(r io.Reader) (*Document, error) {
	var out Document

	if r == nil {
		return nil, fs.ErrNotExist
	}

	// parser
	p := parser.NewParser(r)
	// decoder
	dec := decoder{p: p, out: &out}
	// glue
	p.OnToken = dec.OnToken
	p.OnError = dec.OnError

	// Go!
	err := p.Run()
	return &out, err
}

// DecodeBytes ...
func DecodeBytes(b []byte) (*Document, error) {
	return Decode(bytes.NewReader(b))
}

// DecodeString ...
func DecodeString(s string) (*Document, error) {
	return Decode(strings.NewReader(s))
}