#!/usr/bin/env ruby
#
# Fetch list of methods from go-cqhttp docs.

require 'json'
require 'open-uri'

class API
  attr_reader :api_docs_url
  attr_accessor :functions, :current_title, :current_endpoint, :current_params, :current_response, :others

  def initialize(api_docs_url='https://raw.githubusercontent.com/ishkong/go-cqhttp-docs/main/docs/api/README.md')
    @api_docs_url = api_docs_url.freeze
    @functions = {}
    @current_params = {}
    @current_response = {}
    @others = {}
    parse_doc
    @functions.freeze
  end

  def parse_table(table, type)
    output = {}
    table = table.split("\n").select { |i| i[0] == "|" }
    head = table[0].split('|').map(&:strip)[1..]
    head.map! do |i|
      case i
      when /字段/
        i = "name"
      when /类型/
        i = "type"
      when /默认/
        i = "default"
      when /说明/
        i = "description"
      else
        nil
      end
      i
    end

    data = table[2..].map do |line|
      line.split('|').map do |row|
        row.strip.delete('`')
      end[1..]
    end

    data.each do |row|
      if row[0].include? "或"
        row[0] = row[0].split("或")[0].delete(" ")
      end
      output[row[0]] = {}
      row.size.times do |i|
        next if head[i] == "name"
        output[row[0]].merge!({ "#{head[i]}": row[i] })
      end
    end

    instance_variable_set(type, output)
  rescue NoMethodError
    instance_variable_set(type, "error")
  end

  def parse_doc
    URI.parse(@api_docs_url).open&.read&.split("## ")[1..].each do |data|
      zone = data.split("\n\n")
      @current_title = zone[0]
      zone.each_with_index do |line, index|
        if line =~ /^终结点/
          @current_endpoint = line.gsub(/终结点.+`\/(.+)`/, '\1')
        end

        if line =~ /^\*\*(.+)\*\*/  # match **text**
          type = line.gsub(/\*\*(.+)\*\*/, '\1')
          case type
          when "参数"
            parse_table zone[index+1], :@current_params if index+1 <= zone.size-1
          when "响应数据"
            parse_table zone[index+1], :@current_response if index+1 <= zone.size-1
          else
            parse_table zone[index+1], :@others if index+1 <= zone.size-1
          end
        end
      end
      add_function
      cleanup
    end
  end

  def add_function
    if @current_endpoint
      functions[@current_endpoint] = { title: @current_title, params: @current_params.empty? ? nil : @current_params,
                                       response: @current_response.empty? ? nil : @current_response }
      functions[@current_endpoint].merge!({ others: @others }) unless @others.empty?
    end
  end

  def cleanup
    @current_title = nil
    @current_endpoint = nil
    @current_params = {}
    @current_response = {}
    @others = {}
  end
end

puts API.new.functions.then(&JSON.method(:pretty_generate))