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

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

-- Compat
if not loadstring then  loadstring = load  end                        -- Lua 5.3 compat
local HAS_ADV_GETLOCAL  =  not not debug.getinfo(1, 'u').nparams      -- Lua 5.1 compat
local HAS_UNICODE_IDEN  =  not not loadstring 'local ϕ = 1; return ϕ' -- Lua 5.1 compat
local HAS_JIT_LIBRARY   =  type(rawget(_G, 'jit')) == 'table'         -- Non-LuaJIT compat
--

local function format_test (t)
    if t.adv_getlocal and not HAS_ADV_GETLOCAL then return  end
    if t.single then
        return SUITE:addTest(t.name or t.expect, function ()
            local format = format({t.input}, t.options):gsub('^{%s+(.-)%s+}$', function(a) return '{ '..a..' }' end)
            assert_equal('{ '..t.expect..' }', format)
        end, { line = debug.getinfo(2).currentline })
    end
    SUITE:addTest(t.name or t.expect, function ()
        assert_equal(t.expect, format(t.input, t.options))
    end, { line = debug.getinfo(2).currentline })
end

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

local TEST_UPVALUE = 42

--------------------------------------------------------------------------------
-- Basic inline functions

format_test {
    name = 'Basic function formatting',
    adv_getlocal = true,
    single = true,
    input  = function () end,
    expect = 'function () ... end',
}

format_test {
    name = 'Function with a single argument',
    adv_getlocal = true,
    single = true,
    input  = function (a) end,
    expect = 'function (a) ... end',
}

format_test {
    name = 'Function with multiple arguments',
    adv_getlocal = true,
    single = true,
    input  = function (a, b) end,
    expect = 'function (a, b) ... end',
}

format_test {
    name = 'Function with vararg',
    adv_getlocal = true,
    single = true,
    input  = function (...) end,
    expect = 'function (...) ... end',
}

format_test {
    name = 'Function with vararg and multiple arguments',
    adv_getlocal = true,
    single = true,
    input  = function (a, b, ...) end,
    expect = 'function (a, b, ...) ... end',
}

format_test {
    name = 'Closures don\'t affect functions printed in single mode 1',
    adv_getlocal = true,
    single = true,
    input   = function () l = TEST_UPVALUE end,
    expect  = 'function () ... end',
}

format_test {
    name = 'Closures don\'t affect functions printed in single mode 2',
    adv_getlocal = true,
    single = true,
    input  = function () TEST_UPVALUE = true end,
    expect = 'function () ... end',
}

--------------------------------------------------------------------------------
-- Basic elaborate functions

local func_line = curline(3)
format_test {
    name   = 'Singleline elaborate function',
    input  = function () end,
    expect = 'function ()\n    -- Source file: \'./test/test_function.lua\' [Line: '..func_line..']\n\n    ...\nend',
}

local func_line = curline(3)
format_test {
    name   = 'Multiline elaborate function',
    input  = function ()
    end,
    expect = 'function ()\n    -- Source file: \'./test/test_function.lua\' [Lines: '..func_line..' - '..(func_line+1)..']\n\n    ...\nend',
}

local func_line = curline(3)  -- Must be exactly 3 lines above function
format_test {
    name    = 'Elaborate function with upvalue included 1',
    input   = function () l = TEST_UPVALUE end,
    adv_getlocal = true,
    expect  = 'function ()\n    -- Source file: \'./test/test_function.lua\' [Line: '..func_line..']\n    -- Up values:   { TEST_UPVALUE = 42 }\n\n    ...\nend'
}

local func_line = curline(3)  -- Must be exactly 3 lines above function
format_test {
    name    = 'Elaborate function with upvalue included 2',
    input  = function () TEST_UPVALUE = true end,
    adv_getlocal = true,
    expect  = 'function ()\n    -- Source file: \'./test/test_function.lua\' [Line: '..func_line..']\n    -- Up values:   { TEST_UPVALUE = 42 }\n\n    ...\nend'
}

--------------------------------------------------------------------------------
-- Elaborate functions with documentation

format_test {
    name   = 'Basic Func with docs',
    input  = function ()
        -- This is docs
        return true
    end,
    expect = 'function ()\n    -- This is docs\n\n    ...\nend',
}

format_test {
    name   = 'Comments after other code won\'t be included as docs',
    input  = function ()
        -- This is also docs
        if true then  return false end
        -- Some other comment, that won't appear as docs.
        return true
    end,
    expect = 'function ()\n    -- This is also docs\n\n    ...\nend',
}

format_test {
    name   = 'We can leave a space between doc lines',
    input  = function ()
        -- This is docs

        -- This is also docs
        return true
    end,
    expect = 'function ()\n    -- This is docs\n    -- This is also docs\n\n    ...\nend',
}

format_test {
    name   = 'We can also leave a line with an empty comment',
    input  = function ()
        -- This is docs
        --
        -- This is also docs
        return true
    end,
    expect = 'function ()\n    -- This is docs\n    -- \n    -- This is also docs\n\n    ...\nend',
}

format_test {
    name   = 'No opvalues when docs are there',
    input  = function ()
        -- This is docs
        return TEST_UPVALUE
    end,
    expect = 'function ()\n    -- This is docs\n\n    ...\nend',
}

format_test {
    name   = 'Can find docs when body contains the word "function"',
    input  = function ()
    	-- Hi
    	_function()
    end,
    expect = 'function ()\n    -- Hi\n\n    ...\nend',
}

format_test {
    name   = 'Can find docs from string-loaded function',
    input  = loadstring 'return function ()\n--Hello\nend' (),
    expect = 'function ()\n    -- Hello\n\n    ...\nend',
}

format_test {
    name   = 'String-loaded functions without docs, won\'t display Source file comment',
    input  = loadstring 'return function () end' (),
    expect = 'function ()\n    -- Loaded from string\n\n    ...\nend',
}

--------------------------------------------------------------------------------
-- Builtins

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

format_test {
    input  = math.abs,
    expect = 'builtin function (x)\n    -- math.abs\n    -- Returns the absolute value of x.\n\n    ...\nend',
}

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

format_test {
    input  = math.random,
    expect = 'builtin function ([m [, n])\n    -- math.random\n    -- When called without arguments, returns a uniform pseudo-random real\n    -- number in the range [0,1). When called with an integer number m,\n    -- math.random returns a uniform pseudo-random integer in the range [1, m].\n    -- When called with two integer numbers m and n, math.random returns a\n    -- uniform pseudo-random integer in the range [m, n].\n\n    ...\nend',
}

format_test {
    input  = string.byte,
    expect = 'builtin function (s [, i [, j]])\n    -- string.byte\n    -- Returns the internal numerical codes of the characters s[i], s[i+1],\n    -- ..., s[j]. The default value for i is 1; the default value for j is\n    -- i.\n    -- Note that numerical codes are not necessarily portable across\n    -- platforms.\n\n    ...\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 {
    -- NOTE: These tests may be counter to intention, soon.
    input  = math.random,
    options = { short_builtins = true },
    expect = 'math.random',
}

format_test {
    -- NOTE: These tests may be counter to intention, soon.
    input  = { math.cos, math.sin, math.abs },
    options = { short_builtins = true },
    expect = '{ math.cos, math.sin, math.abs }',
}

format_test {
    name     =  'Replace function with short version, if key',
    input    =  { [math.random] = 365 },
    expect   =  '{ [math.random] = 365 }',
}


--------------------------------------------------------------------------------
-- Embedding functions loaded with loadstring

format_test {
    single = true,
    name  = 'It\'s possible to get loadstring functions whole',
    input  = loadstring('return function (a, b) return a + b end')(),
    options = { embed_loaded_funcs = true },
    expect = 'function (a, b) return a + b end',
}

format_test {
    single = true,
    name  = 'Whitespace is automatically stripped from loadstring functions',
    input  = loadstring('return function (a, b)\n    return a + b\nend')(),
    options = { embed_loaded_funcs = true },
    expect = 'function (a, b) return a + b end',
}

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

format_test {
    name = 'When finding the correct function becomes too hard, just ignore it 1',
    single = true,
    adv_getlocal = true,
    options = { embed_loaded_funcs = true },
    input  = loadstring('return function () return function () end end')(),
    expect = 'function () ... end',
}

format_test {
    name = 'When finding the correct function becomes too hard, just ignore it 2',
    single = true,
    adv_getlocal = true,
    options = { embed_loaded_funcs = true },
    input  = loadstring('return function () return function () end end')()(),
    expect = 'function () ... end',
}

format_test {
    name   = 'Can still find body when body contains the word "function"',
    single = true,
    adv_getlocal = true,
    options = { embed_loaded_funcs = true },
    input  = loadstring('return function () function_body() end')(),
    expect = 'function () function_body() end',
}


--------------------------------------------------------------------------------
-- 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    abs    = builtin function (x)        ... end,\n    random = 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    abs    =         function (x)        ... end,\n    random = builtin function ([m [, n]) ... end\n}',
}

format_test {
    -- The function part should align, even if one is loaded from a string.
    adv_getlocal = true,
    input  = { random = math.random, abs = loadstring('return function () return 1 end')() },
    options = { embed_loaded_funcs = true },
    expect = '{\n    abs    =         function ()         return 1 end,\n    random = builtin function ([m [, n]) ...      end\n}',
}

format_test {
    -- The end part should align when both are loaded from strings.
    adv_getlocal = true,
    input  = { a = loadstring'return function(a) return a end'(), b = loadstring'return function (...) return ... end'() },
    options = { embed_loaded_funcs = true },
    expect = '{\n    a = function (a)   return a   end,\n    b = function (...) return ... 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    abs = function (x)    ... end,\n    max = function (a, b) ... end\n}',
}

if HAS_UNICODE_IDEN then
    format_test {
        name = 'Functions with unicode-named parameters should align nicely',
        adv_getlocal = true,
        input  = loadstring 'return { a = function (ψ) return ψ end, b = function (a) return a end }' (),
        expect = '{\n    a = function (ψ) ... end\n    b = function (a) ... end\n}',
    }
end

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

-- NOTE: The following tests are all EXPERIMENTAL! All of the tests use features
-- which may change at any time.

format_test {
    name    = 'Closures do not affect non-upvalue function',
    adv_getlocal = true,
    options = { _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',
}

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

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

return SUITE