--!The Make-like Build Utility based on Lua
--
-- Licensed to the Apache Software Foundation (ASF) under one
-- or more contributor license agreements.  See the NOTICE file
-- distributed with this work for additional information
-- regarding copyright ownership.  The ASF licenses this file
-- to you under the Apache License, Version 2.0 (the
-- "License"); you may not use this file except in compliance
-- with the License.  You may obtain a copy of the License at
--
--     http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
-- 
-- Copyright (C) 2015 - 2017, TBOOX Open Source Group.
--
-- @author      ruki
-- @file        try.lua
--

-- load modules
local utils     = require("base/utils")
local table     = require("base/table")
local string    = require("base/string")
local option    = require("base/option")

-- define module
local sandbox_try = sandbox_try or {}

-- traceback
function sandbox_try._traceback(errors)

    -- not verbose?
    if not option.get("verbose") then
        if errors then
            -- remove the prefix info
            local _, pos = errors:find(":%d+: ")
            if pos then
                return errors:sub(pos + 1)
            end
        end
        return errors
    end

    -- init results
    local results = ""
    if errors then
        results = errors .. "\n"
    end
    results = results .. "stack traceback:\n"

    -- make results
    local level = 2    
    while true do    

        -- get debug info
        local info = debug.getinfo(level, "Sln")

        -- end?
        if not info or (info.name and info.name == "xpcall") then
            break
        end

        -- function?
        if info.what == "C" then
            results = results .. string.format("    [C]: in function '%s'\n", info.name)
        elseif info.name then 
            results = results .. string.format("    [%s:%d]: in function '%s'\n", info.short_src, info.currentline, info.name)    
        elseif info.what == "main" then
            results = results .. string.format("    [%s:%d]: in main chunk\n", info.short_src, info.currentline)    
            break
        else
            results = results .. string.format("    [%s:%d]:\n", info.short_src, info.currentline)    
        end

        -- next
        level = level + 1    
    end    

    -- ok?
    return results
end

-- try 
function sandbox_try.try(block)

    -- get the try function
    local try = block[1]
    assert(try)

    -- get catch and finally functions
    local funcs = block[2]
    if funcs and block[3] then
        table.join2(funcs, block[2])
    end

    -- try to call it
    local ok, errors = xpcall(try, sandbox_try._traceback)
    if not ok then

        -- run the catch function
        if funcs and funcs.catch then
            funcs.catch(errors)
        end
    end

    -- run the finally function
    if funcs and funcs.finally then
        funcs.finally(ok, errors)
    end

    -- ok?
    return utils.ifelse(ok, errors, nil)
end

-- return module
return sandbox_try.try