package read

import (
	"mal-go/list"
	"mal-go/symbol"
	"strings"
)

func ReadString(s string) (any, any) {
	res, err, _ := readInternal(s, 0, nil, "user")
	return res, err
}

func isSymbolChar(c byte) bool {
	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_' || c == '-' || c == '/' || c == '\''
}

func readInternal(s string, pos int, ctx *list.List, ns string) (any, any, int) {
	if pos >= len(s) {
		return ctx, nil, pos
	}
	c := s[pos]

	var res, err any

	if isSymbolChar(c) {
		res, err, pos2 := readSymbol(s, pos, ns)
		return res, err, pos2
	}
	// switch c {
	// case '{':
	// 	res, err, _ = readInternal(s, pos+1, list.Conj(ctx, hash_map.New()), ns)
	// case '[':
	// case '(':
	// }
	return res, err, 0
}

func readSymbol(s string, pos int, ns string) (any, any, int) {
	startingPos := pos
	c := s[pos]
	for isSymbolChar(c) {
		pos += 1
		if pos >= len(s) {
			break
		}
		c = s[pos]
	}
	sym := s[startingPos:pos]
	symNs := ns
	if strings.Contains(sym, "/") {
		splitIdx := strings.Index(s, "/")
		symNs = s[startingPos:splitIdx]
		sym = s[splitIdx+1 : pos]
	}
	return symbol.Intern(symNs, sym), nil, pos
}