--[[-- Core Module - Commands
- Factorio command making module that makes commands with better parse and more modularity
@core Commands
@alias Commands

@usage--- Full code example, see below for explaination
Commands.new_command('repeat-name', 'Will repeat you name a number of times in chat.')
:add_param('repeat-count', false, 'number-range-int', 1, 5) -- required int in range 1 to 5 inclusive
:add_param('smiley', true, function(input, player, reject) -- optional boolean default false
    if not input then return end
    if input:lower() == 'true' or input:lower() == 'yes' then
        return true
    else
        return false
    end
end)
:set_defaults{ smiley=false }
:set_flag('admin_only', true) -- command is admin only
:add_alias('name', 'rname') -- allow alias: name and rname
:register(function(player, repeat_count, smiley, raw)
    game.print(player.name..' used a command with input: '..raw)

    local msg = ') '..player.name
    if smiley then
        msg = ':'..msg
    end

    for 1 = 1,repeat_count do
        Command.print(1..msg)
    end
end)

@usage--- Example Command:
-- How for the fun part making the commands, the commands can be set up with any number of params and flags that you want,
-- you can add aliases for the commands and set default values for optional params and of course register your command callback
-- in our example we will just have a command that will repeat the users name in chat X amount of times and only allow admins to use it.

-- First we create the new command, nb this will not register the command to the game this is done at the end, we will call
-- the command "repeat-name" and set the help message as follows:
Commands.new_command('repeat-name', 'Will repeat you name a number of times in chat.')

-- Now for our first param we will call "repeat-count" and it will be a required value between 1 and 5 inclusive:
:add_param('repeat-count', false, 'number-range-int', 1, 5)

-- Our second param we need a custom parse for but we have not defined it, this is an option for when it is unlikely for
-- any other command to use the same input type; however in our case it will just be a boolean which should be noted as being
-- included in the general command parse config. As for the param its self it will be called "smiley" and will be optional with
-- a default value of false:
:add_param('smiley', true, function(input, player, reject)
    -- since it is optional the input can be nil, in which case we just return
    if not input then return end
    -- if it is not nil then we check for a truthy value
    if input:lower() == 'true' or input:lower() == 'yes' then
        return true
    else
        -- note that because we did not return nil or reject then false will be passed to command callback, see example parse
        return false
    end
end)

-- Once all params are defined you can now define some default values if you have optional params, the default value will be used only
-- when no value is given as input, if an invalid value is given then the command will still fail and this value will not be used, the
-- default can also be a function which is passed the player using the command and returns a value. Here we set the default for "smiley" to false:
:set_defaults{smiley=false}

-- Another example of defaults if we have: item, amount[opt], player[opt]
:set_defaults{
    amount = 50, -- more than one value can be set at a time
    player = function(player)
        return player -- default is the player using the command
    end
}

-- Now the params are set up we can alter how the command works, we can set auth flags, add aliases to this command or enable "auto concat"
-- which is when you want all extra words to be concatenated onto the end of the last param, useful for reason or messages:
:set_flag('admin_only', true) -- in our case we want "admin_only" to be set to true so only admins can use the command
:add_alias('name', 'rname') -- we also add two aliases here: "name" and "rname" which point to this command
-- :enable_auto_concat() we do not use this in our case but this can also be used to enable the "auto concat" feature

-- And finally we want to register a callback to this command, the callback is what defines what the command does, can be as complex as you
-- want it to be to as simple as our example; the command receives two params plus all that you have defines:
-- 1) the player who used the command
-- 2) in our case repeat_count which will be a number
-- 3) in our case smiley which will be a boolean
-- 4) the raw input; this param is always last as is always present as a catch all
:register(function(player, repeat_count, smiley, raw)
    -- this is to show the value for raw as this is an example command, the log file will also show this
    game.print(player.name..' used a command with input: '..raw)
    local msg = ') '..player.name
    if smiley then
        -- this is where that smiley param is used
        msg = ':'..msg
    end
    for 1 = 1,repeat_count do
        -- this print function will return ANY value to the user in a desync safe manor, this includes if the command was used through rcon
        Command.print(1..msg)
    end
    -- see below for what else can be used here
end)

-- Other values that can be returned from register
Commands.print(any,colour[opt]) -- this will return any value value to the user including if it is ran through rcon console
Commands.error(message[opt]) -- this returns a warning to the user, aka an error that does not prevent execution of the command
return Commands.error(message[opt]) -- this returns an error to the user, and will halt the command execution, ie no success message is returned
Commands.success(message[opt]) -- used to return a success message however don't use this method see below
return Commands.success(message[opt]) -- will return the success message to the user and your given message, halts execution
return <any> -- if any value is returned then it will be returned to the player via a Commands.success call

@usage--- Example Authenticator:
-- The command system is best used when you can control who uses commands;
-- to do this would would need to define an authenticator which is ran every time a command is run;
-- in this example I will show a simple one that requires certain commands to require the user to be a game admin.

-- For our admin only example we will set a flag to true when we want it to be admin only;
-- when we define the command will will use :set_flag('admin_only', true);
-- then inside the authenticator we will test if the flag is present using: if flags.admin_only then

-- When the authenticator is called by the command handler it will be passed 4 arguments:
-- 1) player - the player who used the command
-- 2) command - the name of the command that is being used
-- 3) flags - the flags which have been set for this command, flags are set with :set_flag(name, value)
-- 4) reject - the reject function which is the preferred method to prevent execution of the command

-- No return is required to allow the command to execute but it is best practice to return true;
-- we do this in two cases in our authenticator:
-- 1) when the "admin_only" flag is not set, which we take assume that any one can use it
-- 2) when the "admin_only" flag is set, and the player is admin

-- When want to prevent exicution of the command we must reject it, listed is how that can be done:
-- 1) return false -- this is the most basic rejection and should only be used while testing
-- 2) return reject -- returning the reject function is as a fail safe in case you forget to call it, same as returning false
-- 3) reject() -- this will block execution without to allowing further code to be ran in your authenticator
-- 4) reject('This command is for admins only!') -- Using reject as a function allows a error message to be returned
-- 5) return reject() -- using return on either case above is best practice as you should execute all your code before rejecting

-- Example Code:
Commands.add_authenticator(function(player, command, flags, reject)
    -- Check if the command is admin only
    if flags.admin_only then
        -- Return true if player is admin, or reject and return error message
        return player.admin or reject('This command is for admins only!')
    else
        -- Return true if command was not admin only
        return true
    end
end)

@usage--- Example Parse:
-- Before you make a command it is important to understand the most powerful feature of this command handler;
-- when you define a command you are able to type the params and have then be parsed and validated before your command is executed;
-- This module should is paired with a general command parse but you may want to create your own.

-- For our example we will create a parse to accept only integer numbers in a given range:
-- 1) we will give it the name "number-range-int" this is the "type" that the input is expected to be
-- 2) when we define the type we will also define the min and max of the range so we can use the function more than once
:add_param('repeat_count', false, 'number-range-int', 5, 10) -- "repeat_count" is required "number-range-int" in a range 5 to 10 inclusive

-- The command parse will be passed 3 arguments plus any other which you define, in our case:
-- 1) input - the input that has been given by the user for this param, the role of this function is to transform this value
-- nb: the input is a string but can be nil if the param is marked as optional
-- 2) player - the player who is using the command, this is always present
-- 3) reject - the reject function to throw an error to the user, this is always present
-- 4) range_min - the range min, this is user defined and has the value given when the param is defined
-- 5) range_max - the range max, this is user defined and has the value given when the param is defined

-- When returning from the param parse you have a few options with how to do this:
-- 1) you return the new value for the param (any non nil value) this value is then passed to the command callback
-- 2) not returning will cause a generic invalid error and the command is rejected, not recommenced
-- 3) return reject -- this is just a failsafe in case the function is not called, same as no return
-- 4) return reject() -- will give a shorter error message as you pass a nil custom error
-- 5) return reject('Number entered is not in range: '..range_min..', '..range_max) -- returns a custom error to the user
-- nb: if you do not return reject after you call it then you will still be returning nil so there will be a duplicate error message

-- It should be noted that if you want to expand on an existing parse you can use Commands.parse(type, input, player, reject)
-- this function will either return a new value for the input or nil, if it is nil you should return nil to prevent duplicate
-- error messages to the user:
input = Commands.parse('number-int', input, player, reject)
if not input then return end -- nil check

-- Example Code:
Commands.add_parse('number-range-int',function(input, player, reject, range_min, range_max)
    local rtn = tonumber(input) and math.floor(tonumber(input)) or nil -- converts input to number
    if not rtn or rtn < range_min or rtn > range_max then
        -- the input is either not a number or is outside the range
        return reject('Number entered is not in range: '..range_min..', '..range_max)
    else
        -- returns the input as a number value rather than a string, thus the param is now the correct type
        return rtn
    end
end)

]]

local Game = require 'utils.game' --- @dep utils.game
local player_return,write_json = _C.player_return, _C.write_json --- @dep expcore.common

local Commands = {
    --- Values returned by the signal functions to cause the command system to react
    defines = {
        error='CommandError',
        unauthorized='CommandErrorUnauthorized',
        success='CommandSuccess'
    },
    --- Custom command data will be stored here
    commands={},
    --- Set true to have authorize fail if a callback fails to run, more secure
    authorization_fail_on_error=false,
    --- Custom function are stored here which control who can use what commands
    authorization={},
    --- Used to store default functions which are common parse function such as player or number in range
    parse_functions={},
    -- Sends a value to the player, different to success as this does not signal the end of your command
    print=player_return,
    --- Used to store functions which gets added to new custom commands
    _prototype={},
}

--- Authenication.
-- Functions that control who can use commands
-- @section auth

--[[-- Adds an authorization callback, function used to check if a player if allowed to use a command
@tparam function callback the callback you want to register as an authenticator
@treturn number the index it was inserted at use to remove the callback, if anon function used

@usage-- Test if a command is admin only and if the player is admin
local admin_authenticator =
Commands.add_authenticator(function(player, command, flags, reject)
    if flags.admin_only then
        return player.admin or reject('This command is for admins only!')
    else
        return true
    end
end)

]]
function Commands.add_authenticator(callback)
    table.insert(Commands.authorization,callback)
    return #Commands.authorization
end

--[[-- Removes an authorization callback
@tparam function|number callback the callback to remove, an index returned by add_authenticator can be passed
@treturn boolean if the callback found and removed successfuly

@usage-- Removing the admin authenticator, can not be done dueing runtime
Commands.remove_authenticator(admin_authenticator)

]]
function Commands.remove_authenticator(callback)
    if type(callback) == 'number' then
        -- if a number is passed then it is assumed to be the index
        if Commands.authorization[callback] then
            table.remove(Commands.authorization,callback)
            return true
        end
    else
        -- will search the array and remove the key
        local index
        for key,value in pairs(Commands.authorization) do
            if value == callback then
                index = key
                break
            end
        end
        -- if the function was found it is removed
        if index then
            table.remove(Commands.authorization,index)
            return true
        end
    end
    return false
end

--[[-- Mostly used internally, calls all authorization callbacks, returns if the player is authorized
@tparam LuaPlayer player the player that is using the command, passed to callbacks
@tparam string command_name the command that is being used, passed to callbacks
@treturn[1] boolean true player is authorized
@treturn[1] string commands const for success
@treturn[2] boolean false player is unauthorized
@treturn[2] string|locale_string the reason given by the authenticator

@usage-- Test if a player can use "repeat-name"
local authorized, status = Commands.authorize(game.player, 'repeat-name')

]]
function Commands.authorize(player,command_name)
    local failed
    if not player then return true end
    local command_data = Commands.commands[command_name]
    if not command_data then return false end

    -- function passed to authorization callback to make it simpler to use
    local auth_fail = function(error_message)
        failed = error_message or {'expcore-commands.unauthorized'}
        return Commands.defines.unauthorized
    end

    -- loops over each authorization callback if any return false or unauthorized command will fail
    for _,callback in pairs(Commands.authorization) do
        -- callback(player: LuaPlayer, command: string, flags: table, reject: function(error_message?: string))
        local success, rtn = pcall(callback,player,command_name,command_data.flags,auth_fail)
        -- error handler
        if not success then
            -- the callback failed to run
            log('[ERROR] Authorization failed: '..rtn)
            if Commands.authorization_fail_on_error then
                failed = 'Internal Error'
            end
        elseif rtn == false or rtn == Commands.defines.unauthorized or rtn == auth_fail or failed then
            -- the callback returned unauthorized, failed be now be set if no value returned
            failed = failed or {'expcore-commands.unauthorized'}
            break
        end
    end

    -- checks if the authorization failed
    if failed then
        return false, failed
    else
        return true, Commands.defines.success
    end
end

--- Getters.
-- Functions that get commands
-- @section getters

--[[-- Gets all commands that a player is allowed to use, game commands are not included
@tparam[opt] LuaPlayer player the player that you want to get commands of, nil will return all commands
@treturn table all commands that that player is allowed to use, or all commands

@usage-- Get the command you are allowed to use
local commands = Commands.get(game.player)

@usage-- Get all commands that are registered
local commands = Commands.get()

]]
function Commands.get(player)
    player = Game.get_player_from_any(player)
    if not player then return Commands.commands end
    local allowed = {}
    for name,command_data in pairs(Commands.commands) do
        if Commands.authorize(player,name) then
            allowed[name]=command_data
        end
    end
    return allowed
end

--[[-- Searches command names and help messages to find possible commands, game commands are included
@tparam string keyword the word which you are trying to find in your search
@tparam[opt] LuaPlayer player the player to get allowed commands of, if nil all commands are searched
@treturn table all commands that contain the key word, and allowed by player if player given

@usage-- Get all commands which "repeat"
local commands = Commands.search('repeat')

@usage-- Get all commands which "repeat" and you are allowed to use
local commands = Commands.search('repeat', game.player)

]]
function Commands.search(keyword,player)
    local custom_commands = Commands.get(player)
    local matches = {}
    keyword = keyword:lower()
    -- loops over custom commands
    for name,command_data in pairs(custom_commands) do
        -- combines name help and aliases into one message to be searched
        local search = string.format('%s %s %s',name,command_data.help,table.concat(command_data.aliases,' '))
        if search:lower():match(keyword) then
            matches[name] = command_data
        end
    end
    -- loops over the names of game commands
    for name,description in pairs(commands.game_commands) do
        if name:lower():match(keyword) then
            -- because game commands lack some stuff that the custom ones have they are formated
            matches[name] = {
                name=name,
                help=description,
                description='',
                aliases={}
            }
        end
    end
    return matches
end

--- Parse.
-- Functions that help with parsing
-- @section parse

--[[-- Adds a parse function which can be called by name (used in add_param)
nb: this is not required as you can use the callback directly this just allows it to be called by name
@tparam string name the name of the parse, should be the type like player or player_alive, must be unique
@tparam function callback the callback that is ran to parse the input
@treturn boolean was the parse added will be false if the name is already used

@usage-- Adding a parse to validate ints in a given range
Commands.add_parse('number-range-int', function(input, player, reject, range_min, range_max)
    local rtn = tonumber(input) and math.floor(tonumber(input)) or nil -- converts input to number
    if not rtn or rtn < range_min or rtn > range_max then
        -- the input is either not a number or is outside the range
        return reject('Number entered is not in range: '..range_min..', '..range_max)
    else
        -- returns the input as a number rather than a string, thus the param is now the correct type
        return rtn
    end
end)

]]
function Commands.add_parse(name,callback)
    if Commands.parse_functions[name] then
        return false
    else
        Commands.parse_functions[name] = callback
        return true
    end
end

--[[-- Removes a parse function, see add_parse for adding them
@tparam string name the name of the parse to remove

@usage-- Removing a parse
Commands.remove_parse('number-range-int')

]]
function Commands.remove_parse(name)
    Commands.parse_functions[name] = nil
end

--[[-- Intended to be used within other parse functions, runs a parse and returns success and new value
@tparam string name the name of the parse to call, must be registered parse
@tparam string input string the input to pass to the parse, must be a string but not necessarily the original input
@tparam LuaPlayer player the player that is using the command
@tparam function reject the reject function that was passed by the command hander
@treturn any the new value for the input, may be nil, if nil then either there was an error or input was nil

@usage-- Parsing a int in a given range
local parsed_input = Commands.parse('number-range-int', '7', player, reject, 1, 10) -- valid range 1 to 10

]]
function Commands.parse(name,input,player,reject,...)
    if not Commands.parse_functions[name] then return end
    local success,rtn = pcall(Commands.parse_functions[name],input,player,reject,...)
    if not success then error(rtn,2) return end
    if not rtn then return end
    if rtn == Commands.defines.error then return end
    return rtn
end

--- Creation.
-- Functions that create a new command
-- @section creation

--[[-- Creates a new command object to added details to, note this does not register the command to the game api
@tparam string name the name of the command to be created
@tparam string help the help message for the command
@treturn Commands._prototype this will be used with other functions to generate the command functions

@usage-- Define a new command
local command =
Commands.new_command('repeat-name', 'Will repeat you name a number of times in chat.')

]]
function Commands.new_command(name,help)
    local command = setmetatable({
        name=name,
        help=help,
        callback=function() Commands.internal_error(false,name,'No callback registered') end,
        auto_concat=false,
        min_param_count=0,
        max_param_count=0,
        flags={}, -- stores flags that can be used by auth
        aliases={}, -- n = name: string
        params={}, -- [param_name] = {optional: boolean, default: any, parse: function, parse_args: table}
    }, {
        __index= Commands._prototype
    })
    Commands.commands[name] = command
    return command
end

--[[-- Adds a new param to the command this will be displayed in the help and used to parse the input
@tparam string name the name of the new param that is being added to the command
@tparam[opt=false] boolean optional is this param required for this command, these must be after all required params
@tparam[opt=pass function through] ?string|function parse this function will take the input and return a new (or same) value
@param[opt] ... extra args you want to pass to the parse function; for example if the parse is general use
@treturn Commands._prototype pass through to allow more functions to be called

@usage-- Adding a param which has an parse defined
command:add_param('repeat-count', false, 'number-range-int', 1, 5)

@usage-- Adding a param which has a custom parse, see Commands.add_parse for details
command:add_param('smiley', true, function(input, player, reject)
    if not input then return end
    return input:lower() == 'true' or input:lower() == 'yes' or false
end)

]]
function Commands._prototype:add_param(name,optional,parse,...)
    local parse_args = {...}
    if type(optional) ~= 'boolean' then
        parse_args = {parse,...}
        parse = optional
        optional = false
    end
    parse = parse or function(string) return string end
    self.params[name] = {
        optional=optional,
        parse=parse,
        parse_args=parse_args
    }
    self.max_param_count = self.max_param_count+1
    if not optional then
        self.min_param_count = self.min_param_count+1
    end
    return self
end

--[[-- Add default values to params, only as an effect if the param is optional, if default value is a function it is called with acting player
@tparam table defaults table which is keyed by the name of the param and the value is the default value
@treturn Commands._prototype pass through to allow more functions to be called

@usage-- Adding default values
command:set_defaults{
    smiley = false,
    -- not in example just used to show arguments given
    player_name = function(player)
        return player.name
    end
}

]]
function Commands._prototype:set_defaults(defaults)
    for name,value in pairs(defaults) do
        if self.params[name] then
            self.params[name].default = value
        end
    end
    return self
end

--[[-- Adds a tag to the command which is passed via the flags param to the authenticators, can be used to assign command roles or type
@tparam string name the name of the tag to be added, set to true if no value is given
@tparam[opt=true] any value the tag that you want can be anything that the authenticators are expecting
@treturn Commands._prototype pass through to allow more functions to be called

@usage-- Setting a custom flag
command:set_flag('admin_only', true)

@usage-- When value is true it does not need to be given
command:set_flag('admin_only')

]]
function Commands._prototype:set_flag(name,value)
    value = value or true
    self.flags[name] = value
    return self
end

--[[-- Adds an alias, or multiple, that will also be registered with the same callback, eg /teleport can be used as /tp
@tparam string any ... amount of aliases that you want this command to be callable with
@treturn Commands._prototype pass through to allow more functions to be called

@usage-- Added multiple aliases to a command
command:add_alias('name', 'rname')

]]
function Commands._prototype:add_alias(...)
    for _,alias in pairs({...}) do
        table.insert(self.aliases,alias)
        --Commands.alias_map[alias] = self.name
    end
    return self
end

--[[-- Enables auto concatenation of any params on the end so quotes are not needed for last param
nb: this will disable max param checking as they will be concatenated onto the end of that last param
this can be useful for reasons or longs text, can only have one per command
@treturn Commands._prototype pass through to allow more functions to be called

@usage-- Enable auto concat for a command
command:enable_auto_concat()

]]
function Commands._prototype:enable_auto_concat()
    self.auto_concat = true
    return self
end

--[[-- Adds the callback to the command and registers all aliases, params and help message with the game api
nb: this must be the last function ran on the command and must be done for the command to work
@tparam function callback the callback for the command, will receive the player running command, and params added with add_param

@usage-- Registering your command to the game api
command:register(function(player, repeat_count, smiley, _)
    local msg = ') '..player.name
    if smiley then msg = ':'..msg end

    for 1 = 1,repeat_count do
        Command.print(1..msg)
    end
end)

]]
function Commands._prototype:register(callback)
    -- generates a description to be used
    self.callback = callback
    local description = ''
    for param_name,param_details in pairs(self.params) do
        if param_details.optional then
            description = string.format('%s [%s]',description,param_name)
        else
            description = string.format('%s <%s>',description,param_name)
        end
    end
    self.description = description
    -- registers the command under its own name
    commands.add_command(self.name,{'expcore-commands.command-help',description,self.help},function(command_event)
        local success, err = pcall(Commands.run_command,command_event)
        if not success then log('[ERROR] command/'..self.name..' :: '..err) end
    end)
    -- adds any aliases that it has
    for _,alias in pairs(self.aliases) do
        if not commands.commands[alias] and not commands.game_commands[alias] then
            commands.add_command(alias,{'expcore-commands.command-help',description,self.help},function(command_event)
                command_event.name = self.name
                local success, err = pcall(Commands.run_command,command_event)
                Commands.internal_error(success,self.name,err)
            end)
        end
    end
end

--- Status.
-- Functions that indicate status
-- @section status

--[[-- Sends an error message to the player and when returned will stop exicution of the command
nb: this is for non fatal errors meaning there is no log of this event, use during register callback
@tparam[opt=''] string error_message an optional error message that can be sent to the user
@tparam[opt=utility/wire_pickup] string play_sound the sound to play for the error
@treturn Commands.defines.error return this to command handler to exit execution

@usage-- Send an error message to the player, and stops further code running
return Commands.error('The player you selected is offline')

]]
function Commands.error(error_message,play_sound)
    error_message = error_message or ''
    player_return({'expcore-commands.command-fail',error_message},'orange_red')
    if play_sound ~= false then
        play_sound = play_sound or 'utility/wire_pickup'
        if game.player then game.player.play_sound{path=play_sound} end
    end
    return Commands.defines.error
end

--[[-- Sends an error to the player and logs the error, used with pcall within command handler please avoid direct use
nb: use error(error_message) within your callback to trigger do not trigger directly as code exictuion may still continue
@tparam boolean success the success value returned from pcall, or just false to trigger error
@tparam string command_name the name of the command this is used within the log
@tparam string error_message the error returned by pcall or some other error, this is logged and not returned to player
@treturn boolean the opposite of success so true means to cancel execution, used internally

@usage-- Used in the command system to log handler errors
local success, err = pcall(command_data.callback, player, unpack(params))
if Commands.internal_error(success, command_data.name, err) then
    return command_log(player, command_data, 'Internal Error: Command Callback Fail', raw_params, command_event.parameter, err)
end

]]
function Commands.internal_error(success,command_name,error_message)
    if not success then
        Commands.error('Internal Error, Please contact an admin','utility/cannot_build')
        log{'expcore-commands.command-error-log-format',command_name,error_message}
    end
    return not success
end

--[[-- Sends a value to the player, followed by a command complete message
nb: returning any value from your callback will trigger this function, return this function to prevent duplicate messages
@tparam[opt] any value the value to return to the player, if nil then only success message returned
@treturn Commands.defines.success return this to the command handler to prevent two success messages

@usage-- Print a custom success message
return Commands.success('Your message has been printed')

@usage-- Returning the value has the same result
return 'Your message has been printed'

]]
function Commands.success(value)
    if value ~= nil then player_return(value) end
    player_return({'expcore-commands.command-ran'},'cyan')
    return Commands.defines.success
end

--[[-- Sends a value to the player, different to success as this does not signal the end of your command
@function print
@tparam any value the value that you want to return to the player
@tparam table colour the colour of the message that the player sees

@usage-- Output a message to the player
Commands.print('Your command is in progress')

]]

-- logs command usage to file
local function command_log(player,command,comment,params,raw,details)
    local player_name = player and player.name or '<Server>'
    write_json('log/commands.log',{
        player_name=player_name,
        command_name=command.name,
        comment=comment,
        details=details,
        params=params,
        raw=raw
    })
end

--- Main event function that is ran for all commands, used internally please avoid direct use
-- @tparam table command_event passed directly from command event from the add_command function
-- @usage Commands.run_command(event)
function Commands.run_command(command_event)
    local command_data = Commands.commands[command_event.name]
    -- player can be nil when it is the server
    local player
    if command_event.player_index and command_event.player_index > 0 then
        player = Game.get_player_by_index(command_event.player_index)
    end

    -- checks if player is allowed to use the command
    local authorized, auth_fail = Commands.authorize(player,command_data.name)
    if not authorized then
        command_log(player,command_data,'Failed Auth',{},command_event.parameter)
        Commands.error(auth_fail,'utility/cannot_build')
        return
    end

    -- null param check
    if command_data.min_param_count > 0 and not command_event.parameter then
        command_log(player,command_data,'No Params Given',{},command_event.parameter)
        Commands.error({'expcore-commands.invalid-inputs',command_data.name,command_data.description})
        return
    end

    -- splits the arguments
    local input_string = command_event.parameter or ''
    local quote_params = {} -- stores any " " params
    input_string = input_string:gsub(' "[^"]-"',function(w)
        -- finds all " " params are removes spaces for the next part
        local no_spaces = w:gsub('%s','_')
        local no_quotes = w:sub(2,-2)
        quote_params[no_spaces]=no_quotes
        if command_data.auto_concat then
            -- if auto concat then don't remove quotes as it should be included later
            quote_params[no_spaces]=w
        end
        return no_spaces
    end)

    local raw_params = {} -- stores all params
    local param_number = 0
    local last_index = 0
    for word in input_string:gmatch('%S+') do
        param_number = param_number + 1
        if param_number > command_data.max_param_count then
            -- there are too many params given to the command
            if not command_data.auto_concat then
                -- error as they should not be more
                command_log(player,command_data,'Invalid Input: Too Many Params',raw_params,input_string)
                Commands.error({'expcore-commands.invalid-inputs',command_data.name,command_data.description})
                return
            else
                -- concat to the last param
                if quote_params[word] then
                    -- if it was a " " param then the spaces are re added now
                    raw_params[last_index]=raw_params[last_index]..' '..quote_params[word]
                else
                    raw_params[last_index]=raw_params[last_index]..' '..word
                end
            end
        else
            -- new param that needs to be added
            -- all words are added to an array
            if quote_params[word] then
                -- if it was a " " param then the spaces are re added now
                table.insert(raw_params,quote_params[word])
                last_index = last_index + 1
            else
                table.insert(raw_params,word)
                last_index = last_index + 1
            end
        end
    end

    -- checks param count
    local param_count = #raw_params
    if param_count < command_data.min_param_count then
        command_log(player,command_data,'Invalid Input: Not Enough Params',raw_params,input_string)
        Commands.error({'expcore-commands.invalid-inputs',command_data.name,command_data.description})
        return
    end

    -- parses the arguments
    local index = 1
    local params = {}
    for param_name, param_data in pairs(command_data.params) do
        local parse_callback = param_data.parse
        if type(parse_callback) == 'string' then
            -- if its a string this allows it to be pulled from the common store
            parse_callback = Commands.parse_functions[parse_callback]
        end
        if not type(parse_callback) == 'function' then
            -- if its not a function throw and error
            Commands.internal_error(false,command_data.name,'Invalid param parse '..tostring(param_data.parse))
            command_log(player,command_data,'Internal Error: Invalid Param Parse',params,command_event.parameter,tostring(param_data.parse))
            return
        end
        -- used below as the reject function
        local parse_fail = function(error_message)
            error_message = error_message or ''
            command_log(player,command_data,'Invalid Param Given',raw_params,input_string)
            return Commands.error{'expcore-commands.invalid-param',param_name,error_message}
        end
        -- input: string, player: LuaPlayer, reject: function, ... extra args
        local success,param_parsed = pcall(parse_callback,raw_params[index],player,parse_fail,unpack(param_data.parse_args))
        if Commands.internal_error(success,command_data.name,param_parsed) then
            return command_log(player,command_data,'Internal Error: Param Parse Fail',params,command_event.parameter,param_parsed)
        end
        if param_data.optional == true and raw_params[index] == nil then
            -- if it is optional and param is nil then it is set to default
            param_parsed = param_data.default
            if type(param_parsed) == 'function' then
                -- player: LuaPlayer
                success,param_parsed = pcall(param_parsed,player)
                if Commands.internal_error(success,command_data.name,param_parsed) then
                    return command_log(player,command_data,'Internal Error: Default Value Fail',params,command_event.parameter,param_parsed)
                end
            end
        elseif param_parsed == nil or param_parsed == Commands.defines.error or param_parsed == parse_fail then
            -- no value was returned or error was returned, if nil then give generic error
            if not param_parsed == Commands.defines.error then
                command_log(player,command_data,'Invalid Param Given',raw_params,input_string,param_name)
                Commands.error{'expcore-commands.command-error-param-format',param_name,'please make sure it is the correct type'}
            end
            return
        end
        -- adds the param to the table to be passed to the command callback
        table.insert(params,param_parsed)
        index=index+1
    end

    -- runs the command
    -- player: LuaPlayer, ... command params, raw: string
    table.insert(params,command_data.max_param_count+1,input_string)
    local success, err = pcall(command_data.callback,player,unpack(params))
    if Commands.internal_error(success,command_data.name,err) then
        return command_log(player,command_data,'Internal Error: Command Callback Fail',raw_params,command_event.parameter,err)
    end
    if err == Commands.defines.error or err == Commands.error then
        return command_log(player,command_data,'Custom Error',raw_params,input_string)
    elseif err ~= Commands.defines.success and err ~= Commands.success then
        -- in this case the user has not received any output
        Commands.success(err)
    end
    command_log(player,command_data,'Success',raw_params,input_string)
end

return Commands