-- General use functions for texdoc
--[[ 
Copyright 2008, 2009 Manuel Pégourié-Gonnard
Distributed under the terms of the GNU GPL version 3 or later.
See texdoc.tlu for details.
--]]

-- Load a private environment for this submodule (see texdoc.tlu).
local L = {}
load_env(L, {
    'io', 'os', 'print',
    'config',
})

-- change '/' to '\' on windows
-- Use: internal representation of files always use forward slashes.
-- This function should be called only before displaying a file name.
if os.type == "windows" then
    function w32_path (path)
        return (string.gsub (path, '/', '\\'))
    end
else
    function w32_path (path)
        return path
    end
end

-- remove the last direcory component of a path
if os.type == 'windows' then
    function path_parent(path)
        return string.match(path, '^(.*)[\\/]')
    end
else
    function path_parent(path)
        return string.match(path, '^(.*)/')
    end
end

-- generic error display function (see the error_priority constant)
function err_print (lvl, msg)
    -- be careful: maybe config.verbosity_level is not set yet
    local verbosity_level = config.verbosity_level or tonumber(C.def_verbosity)
    if C.err_priority[lvl] <= verbosity_level then
        io.stderr:write ("texdoc "..lvl..": "..msg.."\n")
    end
end

do --scope of active_debugs
local active_debugs

-- generic debug function
function deb_print(cat, msg)
    -- make sure active_debugs is set
    if not active_debugs then set_active_debugs() end
    -- print message it belongs to an active category
    if active_debugs and active_debugs[cat] or cat == 'XXX' then
        io.stderr:write ("texdoc debug-"..cat..": "..msg.."\n")
    end
end

-- set active_debugs
function set_active_debugs()
    if not config.debug_list then return end
    active_debugs = {}
    -- all debug options imply version info
    if config.debug_list[1] then
        active_debugs.version = true
    else
        return
    end
    -- if 'all' is the first keyword, just activate all categories
    if config.debug_list[1] == 'all' then
        for deb in pairs(C.known_debugs) do
            active_debugs[deb] = true end
        return
    end
    -- activate options from the list
    for _, deb in ipairs(config.debug_list) do
        local deps = C.known_debugs[deb]
        if deps then
            active_debugs[deb] = true
            for _, d in ipairs(deps) do active_debugs[d] = true end
        else
            err_print('warning', "Unknown debug category '"..deb.."'.")
        end
    end
end

end -- scope of active_debugs

-- if file is base..'.'..zip with zip in zipext_list, return: base, zip
-- otherwise, return: file, nil
function parse_zip(file) 
    local zip
    for _, zip in ipairs(config.zipext_list) do
        local l = #zip + 1
        if string.sub(file, -l, -1) == '.'..zip then
            return string.sub(file, 1, -l - 1), zip
        end
    end
    return file, nil
end

-- print a usage message, with the proper 'active values' line
function print_usage()
    local default, files = {}, {}
    for _, param in ipairs(C.usage_settings) do
        local display = param[config[param.name]]
        if config[param.name..'_src'] == 'def' then
            table.insert(default, display)
        elseif config[param.name..'_src'] == 'file' then
            table.insert(files, display)
        end
    end
    def = table.concat(default, ', ')
    conf = table.concat(files, ', ')
    if not (def == '')  then def = def..' (default)' end
    if not (conf == '') then conf = conf..' (user config)' end
    local sep = (def == '' or conf == '') and '' or '; '
    local settings = C.usage_settings_ph..' '..def..sep..conf..'.'
    local usage_msg = string.gsub(C.usage_msg, C.usage_settings_ph, settings)
    print(usage_msg)
end

-- finally export a few symbols
export_symbols(L, {
    'err_print',
    'deb_print',
    'w32_path',
    'parse_zip',
    'print_usage',
    'path_parent',
})