local Luan = require "luan:Luan.luan"
local error = Luan.error
local ipairs = Luan.ipairs or error()
local Number = require "luan:Number.luan"
local long = Number.long or error()
local Db = require "site:/lib/Db.luan"
local languages = require "site:/lib/languages.luan"


local Course = {}

local function from_doc(doc)
	doc.type == "course" or error "wrong type"
	return Course.new {
		id = doc.id
		user_id = doc.course_user_id
		language = doc.course_language
		name = doc.name
		ai_system_prompt = doc.ai_system_prompt
	}
end

local function to_doc(course)
	return {
		type = "course"
		id = course.id
		course_user_id = long(course.user_id)
 		course_language = course.language or error()
		name = course.name or error()
		ai_system_prompt = course.ai_system_prompt or error()
	}
end

function Course.new(course)

	function course.save()
		local doc = to_doc(chat)
		Db.save(doc)
		chat.id = doc.id
	end

	function course.language_name()
		return languages[course.language].name
	end

	return course
end

local function search(query,sort,rows)
	rows = rows or 1000000
	local courses = {}
	local docs = Db.search(query,1,rows,{sort=sort})
	for _, doc in ipairs(docs) do
		courses[#courses+1] = from_doc(doc)
	end
	return courses
end

function Course.get_for_language(language)
	return search("course_language:"..language)
end

function Course.get_by_id(id)
	local doc = Db.get_document("id:"..id)
	return doc and doc.type=="course" and from_doc(doc) or nil
end

return Course