---------------------------------------------------------
-- Minetest :: Chat History Mod v2.0 (chat_history)
-- See "chathist.txt" for licensing and other information
-- Copyright (c) 2016-2018, Leslie E. Krause
---------------------------------------------------------

chat_history = {} -- global namespace
local buffer = {}
local buffer_limit = nil
local review_limit = 200

if false then
minetest.register_on_chat_message( function( sender, message )
    table.insert( buffer, { sender = sender, time = os.time( ),
message = message } )
    if buffer_limit and #buffer > buffer_limit then
        table.remove( buffer, 1 )
    end
end)
end

chat_history.add_chat = function (sender, message)
    table.insert( buffer, { sender = sender, time = os.time( ),
message = message } )
    if buffer_limit and #buffer > buffer_limit then
        table.remove( buffer, 1 )
    end
end

local old_chatcommand = minetest.chatcommands[ "msg" ].func

minetest.chatcommands[ "msg" ].func = function( sender, param )
    local recipient, message = string.match( param,
"^([A-Za-z0-9_]+)%s(.+)$" )

    if recipient and message then
        minetest.sound_play( "mailbox_chime", { to_player = recipient, gain = 0.5, loop = false } )
        table.insert( buffer, { sender = sender, recipient = recipient, time = os.time( ), message = message } )
        if buffer_limit and #buffer > buffer_limit then
            table.remove( buffer, 1 )
        end
    end

    return old_chatcommand (sender, param)
end

local find_phrase = function( source, phrase )
    -- sanitize search phrase and convert to regexp pattern
    local sanitizer =
    {
        ["^"] = "%^";
        ["$"] = "%$";
        ["("] = "%(";
        [")"] = "%)";
        ["%"] = "%%";
        ["."] = "%.";
        ["["] = "";
        ["]"] = "";
        ["*"] = "%w*";
        ["+"] = "%w+";
        ["-"] = "%-";
        ["?"] = "%w";
    }
    return string.find( string.upper( source ), ( string.gsub( string.upper( phrase ), ".", sanitizer ) ) )     -- parens capture only first return value of gsub
end

local get_player_list = function( )
    local player_list = { }
    for i, p in ipairs( minetest.get_connected_players( ) ) do
        table.insert( player_list, p:get_player_name( ) )
    end
    table.sort( player_list, function( a, b ) return a < b end)    -- sort modifies table, hence the need to create a local copy
    return player_list
end

local get_player_formspec = function( recipient, meta, filter_player, is_filter_pm, is_filter_shout )
    local filter_player_idx = 1
    local review_count = 0
    local buffer_count = #buffer
    local formspec = "size[11,7.8]"
        .. default.gui_bg
        .. default.gui_bg_img

--  formspec = formspec .. "textarea[0.3,0.3;11,7.5;buffer;Chat History (Last " .. ( #buffer == buffer_limit and buffer_limit or #buffer ) .. " Messages);\n"
    formspec = formspec .. "textarea[0.3,0.5;11,7.5;buffer;Chat History ("
        .. ( meta.filter_phrase == "" and "All Player Messages" or "Player Messages Containing '" .. minetest.formspec_escape( meta.filter_phrase ) .. "'" ) .. ");"

    while buffer_count > 0 and review_count < review_limit do
        local m = buffer[ buffer_count ]

        if ( filter_player == "" or filter_player == m.sender ) and ( meta.filter_phrase == "" or find_phrase( m.message, meta.filter_phrase ) ) and
        not( is_filter_shout == true and string.byte( m.message ) ~= 33 or is_filter_pm == true and not m.recipient ) and string.byte( m.sender ) ~= 95 then
            if not m.recipient then
                            formspec = formspec .. string.format( "\\[%s\\] <%s> %s\n", os.date( "%X", m.time ), m.sender, minetest.formspec_escape( m.message ) )
                review_count = review_count + 1
            elseif m.recipient == recipient then
                formspec = formspec .. string.format( "\\[%s\\] PM from %s: %s\n", os.date( "%X", m.time ), m.sender, minetest.formspec_escape( m.message ) )
                review_count = review_count + 1
            elseif m.sender == recipient then
                formspec = formspec .. string.format( "\\[%s\\] PM to %s: %s\n", os.date( "%X", m.time ), m.recipient, minetest.formspec_escape( m.message ) )
                review_count = review_count + 1
            end
        end
        buffer_count = buffer_count - 1
    end

    formspec = formspec .. "]"
        .. "label[9,0;" .. os.date( "%X" ) .. "]"
        .. "label[0,7.2;Player:]"
        .. "dropdown[1,7.2;3.5,1;filter_player;"
    for i, p in pairs( meta.player_list ) do
        formspec = formspec .. "," .. p
        if p == filter_player then
            filter_player_idx = 1 + i    -- don't forget to skip over first entry
        end
    end

    formspec = formspec .. ";" .. filter_player_idx .. "]"
        .. "checkbox[4.5,7;is_filter_pm;Only PMs;" .. tostring( is_filter_pm ) .. "]"
        .. "checkbox[6.5,7;is_filter_shout; Only Shouts;" .. tostring( is_filter_shout ) .. "]"
        .. "button[9,7;2,1;update;Update]"
--      .. "hidden[filter_phrase;" .. filter_phrase .. "]"

    return formspec
end

local get_server_formspec = function( recipient, meta )
    local filter_player_idx = 1
    local review_count = 0
    local buffer_count = #buffer
    local formspec = "size[11,7.8]"
        .. default.gui_bg
        .. default.gui_bg_img

    formspec = formspec .. "textarea[0.3,0.5;11,7.5;buffer;Chat History (All Server Messages);"

    while buffer_count > 0 and review_count < review_limit do
        local m = buffer[ buffer_count ]

        if m.sender == meta.filter_server and ( not m.recipient or m.recipient == recipient ) then
                        formspec = formspec .. string.format( "\\[%s\\] %s\n", os.date( "%X", m.time ),
                minetest.formspec_escape( m.recipient and m.message or "*** " .. m.message ) )
            review_count = review_count + 1
        end
        buffer_count = buffer_count - 1
    end

    formspec = formspec .. "]"
        .. "label[9,0;" .. os.date( "%X" ) .. "]"
        .. "label[0,7.2;" .. meta.filter_description .. "]"
        .. "button[9,7;2,1;update;Update]"

    return formspec
end

local on_close_player_formspec = function ( meta, player, fields )
    local name = player:get_player_name( )

    -- TODO: should we check buffer modification time to prevent flood of update requests?
    if fields.filter_player then
        minetest.update_form( player, get_player_formspec( name, meta, string.match( fields.filter_player, "^([A-Za-z0-9_-]*)" ), fields.is_filter_pm == "true", fields.is_filter_shout == "true" ) )
    end
end

local on_close_server_formspec = function ( meta, player, fields )
    local name = player:get_player_name( )

    if fields.update then
        minetest.update_form( player, get_server_formspec( name, meta ) )
    end
end

chat_history.add_message = function ( sender, recipient, message )
    table.insert( buffer, { sender = sender, recipient = recipient, time = os.time( ), message = message } )
end

chat_history.open = function ( name, filter_player )
    local meta = { filter_phrase = "", player_list = get_player_list( ) }
    minetest.create_form( meta, minetest.get_player_by_name( name ), get_player_formspec( name, meta, filter_player or "", false, false ), on_close_player_formspec )
end

minetest.register_chatcommand( "chat", {
        description = "View the recent chat history with optional message filters.",
        func = function( name, param )
        if param ~= "" and not minetest.player_exists( param ) then
            return false, "Unknown player specified."
        else
            -- we must save player list, because client doesn't update formspec drop-downs correctly
            local meta = { filter_phrase = "", player_list = get_player_list( ) }
            minetest.create_form( meta, minetest.get_player_by_name( name ), get_player_formspec( name, meta, param, false, false ), on_close_player_formspec )
        end
    end
} )

minetest.register_chatcommand( "c", {
        description = "View the recent chat history given a search pattern.",
        func = function( name, param )
        if string.len( param ) < 3 or string.len( param ) > 30 then
            return false, "Invalid search pattern specified."
        else
            -- we must save player list, because client doesn't update formspec drop-downs correctly
            local meta = { filter_phrase = param, player_list = get_player_list( ) }
            minetest.create_form( meta, minetest.get_player_by_name( name ), get_player_formspec( name, meta, "", false, false ), on_close_player_formspec )
        end
    end
} )

minetest.register_chatcommand( "chatinfo", {
        description = "View automated info notifications.",
        func = function( name, param )
        local meta = { filter_server = "_infobot", filter_description = "Showing info notifications only" }
        minetest.create_form( meta, minetest.get_player_by_name( name ), get_server_formspec( name, meta ), on_close_server_formspec )
    end
} )

minetest.register_on_joinplayer( function( player )
    local name = player:get_player_name( )
    chat_history.add_message( "_infobot", nil, name .. " joined the game." )

    if minetest.get_modpath( "chat2" ) then
        minetest.after( 10, function( )
                chat2.send_message( name, 'Use /chat or /c [search_phrase] commands to view chat history with optional message filters.', 0xDDAA55 )
        end)
    end
end)

minetest.register_on_leaveplayer( function( player, is_timeout )
    local name = player:get_player_name( )
    chat_history.add_message( "_infobot", nil, name .. " left the game." )
end)