Hexchat irchighway ebooks chat filter

local name = "ebookspam.lua"
local desc = "mitigate chat spam in #ebooks on IRCHighWay"
local version = "0.5"

hexchat.register(name, version, desc)

-- grey color and also the token used to identify filtered text
local c0 = "\00323"

-- search patterns
local pat_searchook = "^@[Ss]earchook"
local pat_find = "^@[Ff]ind"
local pat_search = "^@[Ss]earch"

local function cm_print(args)
    hexchat.emit_print("Channel Message", args[1], args[2], args[3], args[4])
end

local function cm_print_grey(args)
    args[2] = c0 .. args[2]
    cm_print(args)
end

local function cm_print_stripped(args)
    args[2] = c0 .. hexchat.strip(args[2])
    cm_print(args)
end

-- highlight search terms, change c1 to modify highlight color
local function cm_print_search(args)
    local c1 = "\00324"
    args[2] = hexchat.strip(args[2])
    if args[2]:find(pat_searchook) then
        args[2] = args[2]:gsub(pat_searchook, "@searchook" .. c1)
    elseif args[2]:find(pat_find) then
        args[2] = args[2]:gsub(pat_find, "@find" .. c1)
    else
        args[2] = args[2]:gsub(pat_search, "@search" .. c1)
    end
    args[2] = c0 .. args[2]
    cm_print(args)
end

local function cm_cbk(args)
    if args[2]:find("^" .. c0) then
        return hexchat.EAT_NONE
    elseif args[2]:find(pat_search) or args[2]:find(pat_find) then  -- search syntax
        cm_print_search(args)
        return hexchat.EAT_ALL
    elseif args[2]:find("^@") or args[2]:find("^!") then  -- misc spam and download requests
        cm_print_grey(args)
        return hexchat.EAT_ALL
    elseif args[2]:find("[Tt]ype.*@") or args[2]:find("dlFilter") then  -- bot spam
        cm_print_stripped(args)
        return hexchat.EAT_ALL
    end
    return hexchat.EAT_NONE
end

local function ctcp_print(args)
    args[1] = hexchat.strip(args[1])
    args[1] = c0 .. args[1]
    hexchat.emit_print("CTCP Generic to Channel", args[1], args[2], args[3])
end

local function ctcp_cbk(args)
    if args[1]:find("^" .. c0) then
        return hexchat.EAT_NONE
    elseif args[1]:find("OmenServe") or args[1]:find("FWServer") then
        ctcp_print(args)
        return hexchat.EAT_ALL
    end
    return hexchat.EAT_NONE
end

local help = ""

hexchat.hook_print("Channel Message", cm_cbk)
hexchat.hook_print("CTCP Generic to Channel", ctcp_cbk)