-- chat_utility - Shared functions and data for chat system
--    (component of Chat System)
-- Template attachment: none
--    Include script when needed for chat system interaction
-- Created by: Patrick Ferland
-- Created on: 05/27/2008
 
-- Revision History
    -- 05/27/2008 P.Ferland - New script
    -- 06/02/2008 P.Ferland - Cleanup and documentation
    -- 06/10/2008 P.Ferland - Corrected attach/detach bugs
    -- 06/13/2008 P.Ferland - Removed spurious debugs
    -- 06/20/2008 P.Ferland - Added sender data replacement {.field_name} to channel decoding
    -- 06/23/2008 P.Ferland - Added trigger reference counting as core script
    -- 06/25/2008 P.Ferland - Removed trigger refcount
    -- 06/26/2008 P.Ferland - Added HTML-entity escaping of pipe to prevent breaking Metatags
    -- 07/11/2008 P.Ferland - Converted script registration to work at the template level
    -- 07/15/2008 P.Ferland - Added DENIED status code
    -- 07/22/2008 P.Ferland - Fixed broken script unregister
    -- 07/29/2008 P.Ferland - Added standard "system chat format" function
    -- 07/31/2008 P.Ferland - 0 radius makes spatial global
    -- 09/02/2008 P.Ferland - Added MAX_SEND_BUFFER_SIZE for "Stacking" commands like help, who, etc
    -- 09/08/2008 P.Ferland - Added fallback for system chat color in message formatting to prevent install-time errors
    -- 10/28/2008 P.Ferland - Replaced DoCommand with stylesheet.* for Attach/Detach Template Scripts


-- Constants
PLAYER_CHAT_SCRIPT = '11302:10'
CHAT_ENTITY = '11302:11'

MAX_SEND_BUFFER_SIZE = 500

-- Status codes to return in a chat_entity callback
CHAT_STATUS_CODES =
{

    UNKNOWN = -1,
    OK = 0,
    MODULE_NOT_FOUND = 1,
    SYNTAX_ERROR = 2,
    CHANNEL_NOT_FOUND = 3,
    PROPERTY_NOT_FOUND = 4,
    INVALID_ARGUMENT_VALUE = 5,
    DENIED = 6

}

-- Script Properties

Define Properties()

    -- Exported "library" functions
    ExportFunction('chat_system_channel_name')
    ExportFunction('chat_system_set_callback')
    ExportFunction('chat_system_strip_html')
    ExportFunction('chat_system_send_to_subscribers')
    ExportFunction('chat_system_send_to_subscribers_radial')
    ExportFunction('chat_system_log')
    ExportFunction('chat_system_debug')
    ExportFunction('chat_system_register_player_script')
    ExportFunction('chat_system_unregister_player_script')
    ExportFunction('chat_system_selectable_channel_decode')
    ExportFunction('chat_system_attach_core_player_scripts')
    ExportFunction('chat_system_format_system_message')
    
    -- Exported constants
    ExportConstant('CHAT_STATUS_CODES')
    ExportConstant('MAX_SEND_BUFFER_SIZE')

end

-- Commands
    -- no commands

-- Triggers
    -- no triggers
    
-- Local functions
    -- These functions are exported!

-- Sets callback status, message, and data for a chat_entity
function chat_system_set_callback(endpoint, status, status_text, data)

    local callback = endpoint.chat_system_callback_data
    
    if (callback ~= nil) then
        callback.status = status
        callback.status_text = status_text
        
        if (data == nil) then
            table.clear(callback.data)
        else
            callback.data = data
        end
    end
    
end

-- Returns the requested channel name as formatted for Chat System
function chat_system_channel_name(entity_type, entity_name)

    local channel = {}
    
    -- NOTE:  World should ALWAYS be available
    local w = GetWorld()
    if (w == nil) then
        Log(SEV_INFO, 'CHAT ERROR:  Unable to identify world')
        return
    end
    channel.world = w.cleanName

    channel.qualifier = '/channel/'
    if (entity_type ~= nil) then
        if ( (entity_type == 'place') or (entity_type == 'spatial') ) then
            channel.qualifier = '#'
        elseif (entity_type == 'world') then
            channel.qualifier = ''
        else
            channel.qualifier = '/' .. entity_type .. '/'
        end
    end

    channel.entity = ''
    if (entity_name ~= nil) then
        if (entity_type == 'spatial') then
            channel.entity = entity_name .. '/_spatial_'
        elseif (entity_type ~= 'world') then
            channel.entity = entity_name
        end
    end
    
    return channel.world .. channel.qualifier .. channel.entity
end

-- Sends a given message to all subscribers in a channel
function chat_system_send_to_subscribers(self, sender, channel, message, command)

    local endpoint = nil
    
    if (self.chat_system_subscriptions[channel] == nil) then
        -- chat_system_debug('Empty channel ' .. channel)
    else
        
        for _, endpoint in ipairs(self.chat_system_subscriptions[channel]) do
        
            SendTo(self, 'chat_system_send_message', 0, endpoint, message, channel, sender, command)
        
        end
    
    end
end

-- Sends a given message to all subscribers in a channel within the chat system's radial distance of the sender
    -- Only sends to/from physical entities
function chat_system_send_to_subscribers_radial(self, sender, channel, message, command)

    if (self.chat_system_radius == 0) then
        chat_system_send_to_subscribers(self, sender, channel, message, command)
        return
    end
    
    local endpoint = nil
    
    local x = sender.x
    local y = sender.y
    if ( (x == nil) or (y == nil) ) then
        --chat_system_debug('cannot send radial as self is not physical')
        return -- Cannot send radial message if origination point is unknown
    end
    
    if (self.chat_system_subscriptions[channel] == nil) then
        SendTo(self, 'chat_system_debug', 0, 'Empty channel ' .. channel)
    else
        
        local endpoint = nil
        
        for _, endpoint in ipairs(self.chat_system_subscriptions[channel]) do
        
            local ex = endpoint.x
            local ey = endpoint.y
            
            if ( (ex ~= nil) and (ey ~= nil) ) then -- radial message only goes to entities with physical location
                
                local entity_name = endpoint.name
                if (entity_name == nil) then entity_name = 'entity' end
                
                local dx = ex - x
                local dy = ey - y
                
                if ( (dx * dx) + (dy * dy) <= (self.chat_system_radius * self.chat_system_radius) ) then
                    SendTo(self, 'chat_system_send_message', 0, endpoint, message, channel, sender, command)
                end
             
            end
        
        end
    
    end
end

-- Escapes HTML in chat
function chat_system_strip_html(message)

    return string.gsub(string.gsub(string.gsub(string.gsub(message, "\038", "\038amp;"), '>', "\038gt;"), '<', "\038lt;"), '|', "\038#124;")

end

-- Writes a message to the event log with CHAT SYSTEM prefix
function chat_system_log(message)
    Log(SEV_INFO, 'CHAT SYSTEM:  ' .. message)
end

-- Sends a message to client debugging with CHAT SYSTEM prefix
function chat_system_debug(message)
    Debug('CHAT SYSTEM:  ' .. message)
end

-- Registers a script for attachment to players through Chat System
function chat_system_register_player_script(self, script_id)

    chat_system_log('Registering player script ' .. script_id)

    if (self.chat_system_plugin_player_scripts == nil) then
        chat_system_log('Could not register script!')
        return
    end
    self.chat_system_plugin_player_scripts.detached[script_id] = nil
    self.chat_system_plugin_player_scripts.attached[script_id] = script_id
    
    chat_system_attach_template_script('0:1', script_id)
    
    chat_system_log('Registration complete for ' .. script_id)

end

-- Registers a script for detachment from players through Chat System
function chat_system_unregister_player_script(self, script_id)

    chat_system_log('Unregistering player script ' .. script_id)
    
    if (self.chat_system_plugin_player_scripts == nil) then
        chat_system_log('Could not unregister script!')
        return
    end
    self.chat_system_plugin_player_scripts.detached[script_id] = script_id
    self.chat_system_plugin_player_scripts.attached[script_id] = nil
    
    chat_system_detach_template_script('0:1', script_id)

    chat_system_log('Unregistration complete for ' .. script_id)

end

-- Translates placeholder in "selectable channel" definitions into a proper channel name
function chat_system_selectable_channel_decode(self, sender, selectable_channel)

    local decode_string = self.chat_system_selectable_channels[selectable_channel]
    if (decode_string == nil) then
        return ''
    end
    
    local w = GetWorld()
    local p = GetPlace()
    
    decode_string = string.gsub(decode_string, '{world}', w.cleanName)
    decode_string = string.gsub(decode_string, '{place}', p.name)
    
    -- Custom placeholder fields:  replace {.field_name} with sender.field_name value    
    local sender_data_replacement = ''
    for sender_data_replacement in string.gmatch(decode_string, "{%.[_*%w*]*}") do
        
        local field_name = string.gsub(string.gsub(string.gsub(sender_data_replacement, '{', ''), '}', ''), "%.", '')
        
        local data = sender[field_name]
        if (data == nil) then
            data = 'UNKNOWN'
        end
        
        decode_string = string.gsub(decode_string, sender_data_replacement, data)
    end

    return decode_string

end

function chat_system_attach_core_player_scripts(player)

    chat_system_debug('chat_system_attach_core_player_scripts called (DEPRECATED -- remove reference)')
    -- Special chat system scripts
    if (HasScriptById(player, CHAT_ENTITY) == 0) then
        AttachScriptById(player, CHAT_ENTITY)
    end
    if (HasScriptById(player, PLAYER_CHAT_SCRIPT) == 0) then
        AttachScriptById(player, PLAYER_CHAT_SCRIPT)
    end

end

function chat_system_attach_template_script(template_id, script_id)

    stylesheet.AttachTemplateScript(template_id, script_id)

end

function chat_system_detach_template_script(template_id, script_id)

    stylesheet.DetachTemplateScript(template_id, script_id)

end

function chat_system_format_system_message(text)

    local cs = chat_system_singleton()
    local system_color = '#AB9A89'
    if (cs ~= nil) then
        system_color = cs.chat_system_system_color
    end
    
    return '<font color="' .. system_color .. '">' .. text .. '</font>'

end

function chat_system_singleton()

    local w = GetWorld()
    local cs = w.chat_system
    
    return cs

end