package main

import (
	"errors"

	"github.com/yuin/gopher-lua"
)

// Server holds information about a Gitea server.
type Server struct {
	servername string
	url string
	username string
	token string
}

// Configuration holds data retrieved from a Lua script.
type Configuration struct {
	servers []Server
}

// parseText parses a text value from the configuration file.
func getStringFromTable(L *lua.LState, lobj lua.LValue, key string, out *string) error {
	lv := L.GetTable(lobj, lua.LString(key))
	if text, ok := lv.(lua.LString); ok {
		*out = string(text)
	} else {
		return errors.New("Text is not a string!")
	}
	return nil
}

// parseServerFromTable parses a Lua table into a Server structure.
func parseServerFromTable(L *lua.LState, table lua.LValue) (Server, error) {
	server := Server{}
	if err := getStringFromTable(L, table, "servername", &server.servername); err != nil {
		return server, err
	}
	if err := getStringFromTable(L, table, "username", &server.username); err != nil {
		return server, err
	}
	if err := getStringFromTable(L, table, "token", &server.token); err != nil {
		return server, err
	}
	if err := getStringFromTable(L, table, "url", &server.url); err != nil {
		return server, err
	}
	
	return server, nil
}

// Configuration.Parse parses a Lua configuration file into a Configuration struct.
func (config *Configuration) Parse(fname string) error {
	L := lua.NewState()
	defer L.Close()

	L.DoFile(fname)
	table := L.Get(-1)

	for i := 1; i <= L.ObjLen(table); i++ {
		lserver := L.GetTable(table, lua.LNumber(i))
		if server, err := parseServerFromTable(L, lserver); err == nil {
			config.servers = append(config.servers, server)
		} else {
			return err
		}
	}	
	return nil
}