local helpers = require("test.unit.helpers")(after_each)
local itp = helpers.gen_itp(it)

local cimport = helpers.cimport
local eq = helpers.eq
local ffi = helpers.ffi
local to_cstr = helpers.to_cstr

local strings = cimport('stdlib.h', './src/nvim/strings.h',
                        './src/nvim/memory.h')

describe('vim_strsave_escaped()', function()
  local vim_strsave_escaped = function(s, chars)
    local res = strings.vim_strsave_escaped(to_cstr(s), to_cstr(chars))
    local ret = ffi.string(res)

    -- Explicitly free memory so we are sure it is allocated: if it was not it
    -- will crash.
    strings.xfree(res)
    return ret
  end

  itp('precedes by a backslash all chars from second argument', function()
    eq([[\a\b\c\d]], vim_strsave_escaped('abcd','abcd'))
  end)

  itp('precedes by a backslash chars only from second argument', function()
    eq([[\a\bcd]], vim_strsave_escaped('abcd','ab'))
  end)

  itp('returns a copy of passed string if second argument is empty', function()
    eq('text \n text', vim_strsave_escaped('text \n text',''))
  end)

  itp('returns an empty string if first argument is empty string', function()
    eq('', vim_strsave_escaped('','\r'))
  end)

  itp('returns a copy of passed string if it does not contain chars from 2nd argument', function()
    eq('some text', vim_strsave_escaped('some text', 'a'))
  end)
end)

describe('vim_strnsave_unquoted()', function()
  local vim_strnsave_unquoted = function(s, len)
    local res = strings.vim_strnsave_unquoted(to_cstr(s), len or #s)
    local ret = ffi.string(res)
    -- Explicitly free memory so we are sure it is allocated: if it was not it
    -- will crash.
    strings.xfree(res)
    return ret
  end

  itp('copies unquoted strings as-is', function()
    eq('-c', vim_strnsave_unquoted('-c'))
    eq('', vim_strnsave_unquoted(''))
  end)

  itp('respects length argument', function()
    eq('', vim_strnsave_unquoted('-c', 0))
    eq('-', vim_strnsave_unquoted('-c', 1))
    eq('-', vim_strnsave_unquoted('"-c', 2))
  end)

  itp('unquotes fully quoted word', function()
    eq('/bin/sh', vim_strnsave_unquoted('"/bin/sh"'))
  end)

  itp('unquotes partially quoted word', function()
    eq('/Program Files/sh', vim_strnsave_unquoted('/Program" "Files/sh'))
  end)

  itp('removes ""', function()
    eq('/Program Files/sh', vim_strnsave_unquoted('/""Program" "Files/sh'))
  end)

  itp('performs unescaping of "', function()
    eq('/"Program Files"/sh', vim_strnsave_unquoted('/"\\""Program Files"\\""/sh'))
  end)

  itp('performs unescaping of \\', function()
    eq('/\\Program Files\\foo/sh', vim_strnsave_unquoted('/"\\\\"Program Files"\\\\foo"/sh'))
  end)

  itp('strips quote when there is no pair to it', function()
    eq('/Program Files/sh', vim_strnsave_unquoted('/Program" Files/sh'))
    eq('', vim_strnsave_unquoted('"'))
  end)

  itp('allows string to end with one backslash unescaped', function()
    eq('/Program Files/sh\\', vim_strnsave_unquoted('/Program" Files/sh\\'))
  end)

  itp('does not perform unescaping out of quotes', function()
    eq('/Program\\ Files/sh\\', vim_strnsave_unquoted('/Program\\ Files/sh\\'))
  end)

  itp('does not unescape \\n', function()
    eq('/Program\\nFiles/sh', vim_strnsave_unquoted('/Program"\\n"Files/sh'))
  end)
end)

describe('vim_strchr()', function()
  local vim_strchr = function(s, c)
    local str = to_cstr(s)
    local res = strings.vim_strchr(str, c)
    if res == nil then
      return nil
    else
      return res - str
    end
  end
  itp('handles NUL and <0 correctly', function()
    eq(nil, vim_strchr('abc', 0))
    eq(nil, vim_strchr('abc', -1))
  end)
  itp('works', function()
    eq(0, vim_strchr('abc', ('a'):byte()))
    eq(1, vim_strchr('abc', ('b'):byte()))
    eq(2, vim_strchr('abc', ('c'):byte()))
    eq(0, vim_strchr('a«b»c', ('a'):byte()))
    eq(3, vim_strchr('a«b»c', ('b'):byte()))
    eq(6, vim_strchr('a«b»c', ('c'):byte()))

    eq(nil, vim_strchr('«»', ('«'):byte()))
    -- 0xAB == 171 == '«'
    eq(nil, vim_strchr('\171', 0xAB))
    eq(0, vim_strchr('«»', 0xAB))
    eq(3, vim_strchr('„«»“', 0xAB))

    eq(7, vim_strchr('„«»“', 0x201C))
    eq(nil, vim_strchr('„«»“', 0x201D))
    eq(0, vim_strchr('„«»“', 0x201E))

    eq(0, vim_strchr('\244\143\188\128', 0x10FF00))
    eq(2, vim_strchr('«\244\143\188\128»', 0x10FF00))
    --                   |0xDBFF     |0xDF00  - surrogate pair for 0x10FF00
    eq(nil, vim_strchr('«\237\175\191\237\188\128»', 0x10FF00))
  end)
end)

describe('vim_snprintf()', function()
  local function a(expected, buf, bsize, fmt, ...)
    eq(#expected, strings.vim_snprintf(buf, bsize, fmt, ...))
    if bsize > 0 then
      local actual = ffi.string(buf, math.min(#expected + 1, bsize))
      eq(expected:sub(1, bsize - 1) .. '\0', actual)
    end
  end

  local function i(n) return ffi.cast('int', n) end
  local function l(n) return ffi.cast('long', n) end
  local function u(n) return ffi.cast('unsigned', n) end
  local function ll(n) return ffi.cast('long long', n) end
  local function ul(n) return ffi.cast('unsigned long', n) end
  local function ull(n) return ffi.cast('unsigned long long', n) end

  itp('truncation', function()
    for bsize = 0, 14 do
      local buf = ffi.gc(strings.xmalloc(bsize), strings.xfree)
      a('1.00000001e7', buf, bsize, '%.8g', 10000000.1)
      a('1234567', buf, bsize, '%d', i(1234567))
      a('1234567', buf, bsize, '%ld', l(1234567))
      a('  1234567', buf, bsize, '%9ld', l(1234567))
      a('1234567  ', buf, bsize, '%-9ld', l(1234567))
      a('deadbeef', buf, bsize, '%x', u(0xdeadbeef))
      a('001100', buf, bsize, '%06b', u(12))
      a('one two', buf, bsize, '%s %s', 'one', 'two')
      a('1.234000', buf, bsize, '%f', 1.234)
      a('1.234000e+00', buf, bsize, '%e', 1.234)
      a('nan', buf, bsize, '%f', 0.0 / 0.0)
      a('inf', buf, bsize, '%f', 1.0 / 0.0)
      a('-inf', buf, bsize, '%f', -1.0 / 0.0)
      a('-0.000000', buf, bsize, '%f', -0.0)
      a('漢語', buf, bsize, '%s', '漢語')
      a('  漢語', buf, bsize, '%8s', '漢語')
      a('漢語  ', buf, bsize, '%-8s', '漢語')
      a('漢', buf, bsize, '%.3s', '漢語')
      a('  foo', buf, bsize, '%5S', 'foo')
      a('%%%', buf, bsize, '%%%%%%')
      a('0x87654321', buf, bsize, '%p', ffi.cast('char *', 0x87654321))
      a('0x0087654321', buf, bsize, '%012p', ffi.cast('char *', 0x87654321))
    end
  end)

  itp('positional arguments', function()
    for bsize = 0, 24 do
      local buf = ffi.gc(strings.xmalloc(bsize), strings.xfree)
      a('1234567  ', buf, bsize, '%1$*2$ld', l(1234567), i(-9))
      a('1234567  ', buf, bsize, '%1$*2$.*3$ld', l(1234567), i(-9), i(5))
      a('1234567  ', buf, bsize, '%1$*3$.*2$ld', l(1234567), i(5), i(-9))
      a('1234567  ', buf, bsize, '%3$*1$.*2$ld', i(-9), i(5), l(1234567))
      a('1234567', buf, bsize, '%1$ld', l(1234567))
      a('  1234567', buf, bsize, '%1$*2$ld', l(1234567), i(9))
      a('9 12345 7654321', buf, bsize, '%2$ld %1$d %3$lu', i(12345), l(9), ul(7654321))
      a('9 1234567 7654321', buf, bsize, '%2$d %1$ld %3$lu', l(1234567), i(9), ul(7654321))
      a('9 1234567 7654321', buf, bsize, '%2$d %1$lld %3$lu', ll(1234567), i(9), ul(7654321))
      a('9 12345 7654321', buf, bsize, '%2$ld %1$u %3$lu', u(12345), l(9), ul(7654321))
      a('9 1234567 7654321', buf, bsize, '%2$d %1$lu %3$lu', ul(1234567), i(9), ul(7654321))
      a('9 1234567 7654321', buf, bsize, '%2$d %1$llu %3$lu', ull(1234567), i(9), ul(7654321))
      a('9 1234567 7654321', buf, bsize, '%2$d %1$llu %3$lu', ull(1234567), i(9), ul(7654321))
      a('9 deadbeef 7654321', buf, bsize, '%2$d %1$x %3$lu', u(0xdeadbeef), i(9), ul(7654321))
      a('9 c 7654321', buf, bsize, '%2$ld %1$c %3$lu', i(('c'):byte()), l(9), ul(7654321))
      a('9 hi 7654321', buf, bsize, '%2$ld %1$s %3$lu', 'hi', l(9), ul(7654321))
      a('9 0.000000e+00 7654321', buf, bsize, '%2$ld %1$e %3$lu', 0.0, l(9), ul(7654321))
      a('two one two', buf, bsize, '%2$s %1$s %2$s', 'one', 'two', 'three')
      a('three one two', buf, bsize, '%3$s %1$s %2$s', 'one', 'two', 'three')
      a('1234567', buf, bsize, '%1$d', i(1234567))
      a('deadbeef', buf, bsize, '%1$x', u(0xdeadbeef))
      a('001100', buf, bsize, '%1$0.*2$b', u(12), i(6))
      a('one two', buf, bsize, '%1$s %2$s', 'one', 'two')
      a('001100', buf, bsize, '%06b', u(12))
      a('two one', buf, bsize, '%2$s %1$s', 'one', 'two')
      a('1.234000', buf, bsize, '%1$f', 1.234)
      a('1.234000e+00', buf, bsize, '%1$e', 1.234)
      a('nan', buf, bsize, '%1$f', 0.0 / 0.0)
      a('inf', buf, bsize, '%1$f', 1.0 / 0.0)
      a('-inf', buf, bsize, '%1$f', -1.0 / 0.0)
      a('-0.000000', buf, bsize, '%1$f', -0.0)
    end
  end)
end)

describe('strcase_save()' , function()
  local strcase_save = function(input_string, upper)
    local res = strings.strcase_save(to_cstr(input_string), upper)
    return ffi.string(res)
  end

  itp('decodes overlong encoded characters.', function()
    eq("A", strcase_save("\xc1\x81", true))
    eq("a", strcase_save("\xc1\x81", false))
  end)
end)

describe("reverse_text", function()
  local reverse_text = function(str)
    return helpers.internalize(strings.reverse_text(to_cstr(str)))
  end

  itp("handles empty string", function()
    eq("", reverse_text(""))
  end)

  itp("handles simple cases", function()
    eq("a", reverse_text("a"))
    eq("ba", reverse_text("ab"))
  end)

  itp("handles multibyte characters", function()
    eq("bα", reverse_text("αb"))
    eq("Yötön yö", reverse_text("öy nötöY"))
  end)

  itp("handles combining chars", function()
    local utf8_COMBINING_RING_ABOVE = "\204\138"
    local utf8_COMBINING_RING_BELOW = "\204\165"
    eq("bba" .. utf8_COMBINING_RING_ABOVE .. utf8_COMBINING_RING_BELOW .. "aa",
       reverse_text("aaa" .. utf8_COMBINING_RING_ABOVE .. utf8_COMBINING_RING_BELOW .. "bb"))
  end)

  itp("treats invalid utf as separate characters", function()
    eq("\192ba", reverse_text("ab\192"))
  end)

  itp("treats an incomplete utf continuation sequence as valid", function()
    eq("\194ba", reverse_text("ab\194"))
  end)
end)