local SUITE = require('TestSuite').new('function')
SUITE:setEnviroment{
    format  = require('pretty')
}

--------------------------------------------------------------------------------

local HAS_ADV_GETLOCAL = not not debug.getinfo(1, 'u').nparams  -- Lua 5.1 compat
if not loadstring then  loadstring = load  end                  -- Lua 5.3 compat

local function format_test (t)
    if t.longterm     then return  end
    if t.adv_getlocal and not HAS_ADV_GETLOCAL then return  end
    SUITE:addTest(t.name or t.expect, function ()
    	local input_value      =  t.input
        local input_options    =  t.options
        local expected_result  =  t.expect
    	local actual_result    =  format(input_value, input_options)
        if not t.approx or type(actual_result) ~= 'string' then
            assert_equal(expected_result, actual_result)
        else
            if not actual_result:match(expected_result) then
                error(ASSERT_ERROR_APPROX:format(expected_result, actual_result))
            end
        end
    end, { line = debug.getinfo(2).currentline })
end

local function curline (delta)
	return debug.getinfo(2).currentline + (delta or 0)
end

--------------------------------------------------------------------------------
-- Function printing

format_test {
    adv_getlocal = true,
    input  = function () end,
    expect = 'function () ... end',
}

format_test {
    adv_getlocal = true,
    input  = function (a) end,
    expect = 'function (a) ... end',
}

format_test {
    adv_getlocal = true,
    input  = function (a, b) end,
    expect = 'function (a, b) ... end',
}

format_test {
    adv_getlocal = true,
    input  = function (...) end,
    expect = 'function (...) ... end',
}

format_test {
    adv_getlocal = true,
    input  = function (a, b, ...) end,
    expect = 'function (a, b, ...) ... end',
}

do
    local SOME_RANDOM_UPVALUE = false

    format_test {
        adv_getlocal = true,
        input   = function () l = SOME_RANDOM_UPVALUE end,
        expect  = 'function () ... end',
    }

    format_test {
        adv_getlocal = true,
        input  = function () SOME_RANDOM_UPVALUE = true end,
        expect = 'function () ... end',
    }

    format_test {
        -- More function info is ignored if not at depth 0.
        adv_getlocal = true,
        input  = { a = function () SOME_RANDOM_UPVALUE = true end },
        options = { more_function_info = true },
        expect = '{ a = function () ... end }',
    }


    local func_line = curline(2)  -- Must be exactly 2 lines above function
    format_test {
        input   = function () l = SOME_RANDOM_UPVALUE end,
        adv_getlocal = true,
        options = { more_function_info = true },
        expect  = 'function ()\n\t-- source_file: \'./test/test_function.lua\' [Line: '..func_line..']\n\t-- up_values:   { SOME_RANDOM_UPVALUE = false }\n\n\t...\nend'
    }

    local func_line = curline(2)  -- Must be exactly 2 lines above function
    format_test {
        input  = function () SOME_RANDOM_UPVALUE = true end,
        adv_getlocal = true,
        options = { more_function_info = true },
        expect  = 'function ()\n\t-- source_file: \'./test/test_function.lua\' [Line: '..func_line..']\n\t-- up_values:   { SOME_RANDOM_UPVALUE = false }\n\n\t...\nend'
    }
end

do
    local func_line = curline(2)  -- Must be exactly 2 lines above function
    format_test {
        input   = function () end,
        adv_getlocal = true,
        options = { more_function_info = true },
        expect  = 'function ()\n\t-- source_file: \'./test/test_function.lua\' [Line: '..func_line..']\n\n\t...\nend'
    }
end

do
    local index = 0

    format_test {
        input  = function () index = index + 1; return index end,
        adv_getlocal = true,
        expect  = 'function () ... end'
    }

    local func_line = curline(2)  -- Must be exactly 2 lines above function
    format_test {
        input  = function () index = index + 1; return index end,
        adv_getlocal = true,
        options = { more_function_info = true },
        expect  = 'function ()\n\t-- source_file: \'./test/test_function.lua\' [Line: '..func_line..']\n\t-- up_values:   { index = 0 }\n\n\t...\nend'
    }
end

format_test {
    adv_getlocal = true,
    input  = loadstring('return function () end')(),
    expect = 'function () end',
}

format_test {
    adv_getlocal = true,
    input  = loadstring('return function () return function () end end')(),
    expect = 'function () return function () end end',
}

format_test {
    adv_getlocal = true,
    input  = loadstring('return function () return function () end\nend')()(),
    expect = 'function () end',
}

format_test {
    -- NOTE: This is HARD to fix. It's thus longerterm
    adv_getlocal = true,
    input  = loadstring('return function () return function () end end')()(),
    expect = 'function () end',
}

format_test {
    -- More function info allows one to even get the function whole, if it was defined in a string.
    input  = loadstring('return function (a, b) return a + b end')(),
    options = { more_function_info = true },
    expect = 'function (a, b) return a + b end',
}

format_test {
    -- More function info allows one to even get the function whole, if it was defined in a string.
    input  = loadstring('return function (a, b)\n\treturn a + b\nend')(),
    options = { more_function_info = true },
    expect = 'function (a, b)\n\treturn a + b\nend',
}

do
    local func_line = curline(2)  -- Must be exactly 2 lines above function
    format_test {
        input   = function ()
            -- NOTE: This function must cover 3 lines of code!
        end,
        adv_getlocal = true,
        options = { more_function_info = true },
        expect  = 'function ()\n\t-- source_file: \'./test/test_function.lua\' [Lines: '..func_line..' - '..(func_line+2)..']\n\n\t...\nend',
    }

    local func_line = curline(2)  -- Must be exactly 2 lines above function
    format_test {
        input   = function () --[[ NOTE: This function must cover a single line of code! ]] end,
        adv_getlocal = true,
        options = { more_function_info = true },
        expect  = 'function ()\n\t-- source_file: \'./test/test_function.lua\' [Line: '..func_line..']\n\n\t...\nend',
    }
end

format_test {
    input  = math.abs,
    expect = 'builtin function (x) ... end',
}

format_test {
    input  = math.abs,
    options = { more_function_info = true },
    expect = 'builtin function (x)\n\t-- math.abs\n\t-- Returns the absolute value of x.\n\n\t...\nend',
}

format_test {
    input  = math.random,
    expect = 'builtin function ([m [, n]) ... end',
}

format_test {
    input  = math.random,
    options = { more_function_info = true },
    expect = 'builtin function ([m [, n])\n\t-- math.random\n\t-- When called without arguments, returns a uniform pseudo-random real number in the range [0,1). When called with an integer number m, math.random returns a uniform pseudo-random integer in the range [1, m]. When called with two integer numbers m and n, math.random returns a uniform pseudo-random integer in the range [m, n].\n\n\t...\nend',
}

format_test {
    input  = string.byte,
    options = { more_function_info = true },
    expect = 'builtin function (s [, i [, j]])\n\t-- string.byte\n\t-- Returns the internal numerical codes of the characters s[i], s[i+1], ..., s[j]. The default value for i is 1; the default value for j is i.\n\t-- Note that numerical codes are not necessarily portable across platforms.\n\n\t...\nend',
}

-- short_builtins option: If an builtin is expected to be available by some name
-- in a standard enviroment, return that name, instead of other complex info.

format_test {
    input  = math.random,
    options = { short_builtins = true },
    expect = 'math.random',
}

format_test {
    input  = { math.cos, math.sin, math.abs },
    options = { short_builtins = true },
    expect = '{ math.cos, math.sin, math.abs }',
}

--------------------------------------------------------------------------------
-- Closure creation
-- include_closure option: If a function uses upvalues, return code that creates
-- a closure for that function, including the function code.

-- NOTE: Without AST traversal, it's impossible to garentee that values refered
-- by multiple recursive closures are the same, because they can actually refer
-- to different variables with the same name, as the following example shows:
--
--     local val_a  = 1
--     local func_a = function () return val_a end
--     local val_a  = 2
--     local func_c = function () return func_a() + val_a end

do
    format_test {
        adv_getlocal = true,
        options = { more_function_info = true, include_closure = true },
        input  = function (a, b) return (a > b) and a or b end,
        expect = 'function (a, b) return (a > b) and a or b end',
    }
end

do
    local input_func  =  (function ()
        local i = 0
        return function (a) i = i + a; return i end
    end)()
    for i = 1, 10 do  input_func(1)  end

    format_test {
        adv_getlocal = true,
        options = { more_function_info = true, include_closure = true },
        input  = input_func,
        expect = '(function () local i = 10; return function (a) i = i + a; return i end end)()',
    }
end

do
    local input_func  =  loadstring([[
    return function ()
        local i = 0
        return function (a) i = i + a; return i end
    end]])()()
    for i = 1, 10 do  input_func(1)  end

    format_test {
        name = 'Can include variables in closure',
        adv_getlocal = true,
        options = { more_function_info = true, include_closure = true },
        input  = input_func,
        expect = '(function () local i = 10; return function (a) i = i + a; return i end end)()',
    }
end

format_test {
    name = 'Can include functions in closure',
    adv_getlocal = true,
    options = { more_function_info = true, include_closure = true },
    input  = (function ()
        local custom_max = function (a, b) return (a > b) and a or b end
        return function (a, b) return custom_max(a, b) + 2 end
    end)(),
    expect = '(function () local custom_max = function (a, b) return (a > b) and a or b end; return function (a, b) return custom_max(a, b) + 2 end end)()',
}

format_test {
    name = 'Can include functions defined with `function <name> () ...` style',
    adv_getlocal = true,
    options = { more_function_info = true, include_closure = true },
    input  = (function ()
        local function custom_max (a, b) return (a > b) and a or b end
        return function (a, b) return custom_max(a, b) + 2 end
    end)(),
    expect = '(function () local custom_max = function (a, b) return (a > b) and a or b end; return function (a, b) return custom_max(a, b) + 2 end end)()',
}

do
    local custom_max = function (a, b) return (a > b) and a or b end
    format_test {
        name = 'Can include functions from outside scope into closure',
        adv_getlocal = true,
        options = { more_function_info = true, include_closure = true },
        input  = (function ()
            return function (a, b) return custom_max(a, b) + 2 end
        end)(),
        expect = '(function () local custom_max = function (a, b) return (a > b) and a or b end; return function (a, b) return custom_max(a, b) + 2 end end)()',
    }
end

do
    local a_func = function (x) return x + 2 end
    local b_func = function (x) return a_func(x) * a_func(x) end
    local c_func = function (x) return b_func(a_func(x)) end
    format_test {
        name = 'Can support recursive closures',
        adv_getlocal = true,
        options = { more_function_info = true, include_closure = true },
        input  = c_func,
        expect = '(function () local b_func = (function () local a_func = function (x) return x + 2 end; return function (x) return a_func(x) * a_func(x) end end)(); local a_func = function (x) return x + 2 end; return function (x) return b_func(a_func(x)) end end)()',
    }
end


format_test {
    name    = 'Closures do not affect builtins',
    input  = math.abs,
    options = { more_function_info = true, include_closure = true },
    expect = 'builtin function (x)\n\t-- math.abs\n\t-- Returns the absolute value of x.\n\n\t...\nend',
}

--------------------------------------------------------------------------------
-- Indent functions nicely

format_test {
    -- The tail part should align, letting people focus on the important aspects.
    input  = { random = math.random, abs = math.abs },
    expect = '{\n\tabs    = builtin function (x)        ... end,\n\trandom = builtin function ([m [, n]) ... end\n}',
}

format_test {
    -- The function part should align, if some are builtin and some are not.
    adv_getlocal = true,
    input  = { random = math.random, abs = function (x) return x < 0 and -x or x end },
    expect = '{\n\tabs    =         function (x)        ... end,\n\trandom = builtin function ([m [, n]) ... end\n}',
}

format_test {
    -- No special indent if no special function modifier.
    adv_getlocal = true,
    input  = { max = function(a, b) return a > b and a or b end,
               abs = function (x) return x < 0 and -x or x end
    },
    expect = '{\n\tabs = function (x)    ... end,\n\tmax = function (a, b) ... end\n}',
}


--------------------------------------------------------------------------------

--[[
format_test {
    adv_getlocal = true,
    options = { more_function_info = true, _all_function_info = true, max_depth = 2 },
    input  = function() end,
    expect = '',
}
--]]

return SUITE