###############################################################################
# JSON Beautifier                                                             #
# Copyright (C) 2018-2020 Michael Alexsander                                  #
#-----------------------------------------------------------------------------#
# This Source Code Form is subject to the terms of the Mozilla Public         #
# License, v. 2.0. If a copy of the MPL was not distributed with this         #
# file, You can obtain one at http://mozilla.org/MPL/2.0/.                    #
###############################################################################

class_name JSONBeautifier


# Takes valid JSON (if invalid, it will return a error according with Godot's
# 'validade_json()' method) and a number of spaces for indentation (default is
# '0', in which it will use tabs instead), returning properly formatted JSON.
static func beautify_json(json: String, spaces := 0) -> String:
    var error_message: String = validate_json(json)
    if not error_message.empty():
        return error_message

    var indentation := ""
    if spaces > 0:
        for i in spaces:
            indentation += " "
    else:
        indentation = "\t"

    var quotation_start := -1
    var char_position := 0
    for i in json:
        # Avoid formating inside strings.
        if i == "\"":
            if quotation_start == -1:
                quotation_start = char_position
            elif json[char_position - 1] != "\\":
                quotation_start = -1

            char_position += 1

            continue
        elif quotation_start != -1:
            char_position += 1

            continue

        match i:
            # Remove pre-existing formatting.
            " ", "\n", "\t":
                json[char_position] = ""
                char_position -= 1

            "{", "[", ",":
                if json[char_position + 1] != "}" and\
                        json[char_position + 1] != "]":
                    json = json.insert(char_position + 1, "\n")
                    char_position += 1
            "}", "]":
                if json[char_position - 1] != "{" and\
                        json[char_position - 1] != "[":
                    json = json.insert(char_position, "\n")
                    char_position += 1
            ":":
                json = json.insert(char_position + 1, " ")
                char_position += 1
        
        char_position += 1

    for i in [["{", "}"], ["[", "]"]]:
        var bracket_start: int = json.find(i[0])
        while bracket_start != -1:
            var bracket_end: int = json.find("\n", bracket_start)
            var bracket_count := 0
            while bracket_end != - 1:
                if json[bracket_end - 1] == i[0]:
                    bracket_count += 1
                elif json[bracket_end + 1] == i[1]:
                    bracket_count -= 1

                # Move through the indentation to see if there is a match.
                while json[bracket_end + 1] == indentation:
                    bracket_end += 1

                    if json[bracket_end + 1] == i[1]:
                        bracket_count -= 1

                if bracket_count <= 0:
                    break

                bracket_end = json.find("\n", bracket_end + 1)

            # Skip one newline so the end bracket doesn't get indented.
            bracket_end = json.rfind("\n", json.rfind("\n", bracket_end) - 1)
            while bracket_end > bracket_start:
                json = json.insert(bracket_end + 1, indentation)
                bracket_end = json.rfind("\n", bracket_end - 1)

            bracket_start = json.find(i[0], bracket_start + 1)

    return json


# Takes valid JSON (if invalid, it will return a error according with Godot's
# 'validade_json()' method), returning JSON in a single line.
static func uglify_json(json: String) -> String:
    var quotation_start := -1
    var char_position := 0
    for i in json:
        # Avoid formating inside strings.
        if i == "\"":
            if quotation_start == -1:
                quotation_start = char_position
            elif json[char_position - 1] != "\\":
                quotation_start = -1

            char_position += 1

            continue
        elif quotation_start != -1:
            char_position += 1

            continue

        if i == " " or i == "\n" or i == "\t":
            json[char_position] = ""
            char_position -= 1

        char_position += 1

    return json