local mpack = require('mpack')

local nvimsrcdir = arg[1]
local shared_file = arg[2]
local autodir = arg[3]
local metadata_file = arg[4]
local funcs_file = arg[5]

_G.vim = loadfile(shared_file)()

if nvimsrcdir == '--help' then
  print([[
Usage:
  lua gen_eval.lua src/nvim build/src/nvim/auto

Will generate build/src/nvim/auto/funcs.generated.h with definition of functions
static const array.
]])
  os.exit(0)
end

package.path = nvimsrcdir .. '/?.lua;' .. package.path

local funcsfname = autodir .. '/funcs.generated.h'

local hashy = require'generators.hashy'

local hashpipe = io.open(funcsfname, 'wb')

local funcs = require('eval').funcs
local metadata = mpack.unpack(io.open(metadata_file, 'rb'):read("*all"))
for _,fun in ipairs(metadata) do
  if fun.eval then
    funcs[fun.name] = {
      args=#fun.parameters,
      func='api_wrapper',
      data='&handle_'..fun.name,
    }
  end
end

local funcsdata = io.open(funcs_file, 'w')
funcsdata:write(mpack.pack(funcs))
funcsdata:close()


local names = vim.tbl_keys(funcs)

local neworder, hashfun = hashy.hashy_hash("find_internal_func", names, function (idx)
  return "functions["..idx.."].name"
end)
hashpipe:write("static const EvalFuncDef functions[] = {\n")
for _, name in ipairs(neworder) do
  local def = funcs[name]
  local args = def.args or 0
  if type(args) == 'number' then
    args = {args, args}
  elseif #args == 1 then
    args[2] = 'MAX_FUNC_ARGS'
  end
  local base = def.base or "BASE_NONE"
  local func = def.func or ('f_' .. name)
  local data = def.data or "NULL"
  local fast = def.fast and 'true' or 'false'
  hashpipe:write(('  { "%s", %s, %s, %s, %s, &%s, (FunPtr)%s },\n')
                  :format(name, args[1], args[2], base, fast, func, data))
end
hashpipe:write('  { NULL, 0, 0, BASE_NONE, false, NULL, NULL },\n')
hashpipe:write("};\n\n")
hashpipe:write(hashfun)
hashpipe:close()