-----------------------------------------------------------------------------
-- Xavante WSAPI handler
--
-- Author: Fabio Mascarenhas
-- Copyright (c) 2007 Kepler Project
--
-----------------------------------------------------------------------------

local coxpcall = require "coxpcall"

pcall = coxpcall.pcall
xpcall = coxpcall.xpcall

local common = require"wsapi.common"

local _M = {}

-------------------------------------------------------------------------------
-- Implements WSAPI
-------------------------------------------------------------------------------

local function set_cgivars (req, diskpath, path_info_pat, script_name_pat, extra_vars)
  diskpath = diskpath or req.diskpath or ""
  req.cgivars = {
    SERVER_SOFTWARE   = req.serversoftware,
    SERVER_NAME       = req.parsed_url.host,
    GATEWAY_INTERFACE = "CGI/1.1",
    SERVER_PROTOCOL   = "HTTP/1.1",
    SERVER_PORT       = req.parsed_url.port,
    REQUEST_METHOD    = req.cmd_mth,
    DOCUMENT_ROOT     = diskpath,
    PATH_INFO         = string.match(req.parsed_url.path, path_info_pat) or "",
    PATH_TRANSLATED   = script_name_pat and (diskpath .. script_name_pat),
    SCRIPT_NAME       = script_name_pat,
    QUERY_STRING      = req.parsed_url.query or "",
    REMOTE_ADDR       = string.gsub (req.rawskt:getpeername (), ":%d*$", ""),
    CONTENT_TYPE      = req.headers ["content-type"],
    CONTENT_LENGTH    = req.headers ["content-length"],
  }
  if req.cgivars.PATH_INFO == "" then req.cgivars.PATH_INFO = "/" end
  for n,v in pairs(extra_vars or {}) do
    req.cgivars[n] = v
  end
  for n,v in pairs (req.headers) do
    req.cgivars ["HTTP_"..string.gsub (string.upper (n), "-", "_")] = v
  end
end

local function wsapihandler (req, res, wsapi_run, app_prefix, docroot, app_path, extra_vars)
  local path_info_pat = "^" .. (app_prefix or "") .. "(.*)"
  set_cgivars(req, docroot, path_info_pat, app_prefix, extra_vars)

  local get_cgi_var = function (var)
    return req.cgivars[var] or ""
  end

  local wsapi_env = common.wsapi_env {
    input       = req.socket,
    read_method = "receive",
    error       = io.stderr,
    env         = get_cgi_var
  }
  wsapi_env.APP_PATH = app_path

  local function set_status(status)
    if type(status) == "string" and status:match("^%d+$") then
      status = tonumber(status)
    end

    if type(status) == "number" then
      status = ("%d %s"):format(status, common.status_codes[status])
    end

    res.statusline = "HTTP/1.1 " .. (status or "500 Internal Server Error")
  end

  local function send_headers(headers)
    for h, v in pairs(headers) do
      if h == "Status" or h == "Content-Type" then
        res.headers[h] = v
      elseif type(v) == "string" then
        res:add_header(h, v)
      elseif type(v) == "table" then
        for _, v in ipairs(v) do
          res:add_header(h, tostring(v))
        end
      else
        res:add_header(h, tostring(v))
      end
    end
    res:send_headers()
  end

  local ok, status, headers, res_iter = common.run_app(wsapi_run, wsapi_env)
  if ok then
    set_status(status or 500)
    send_headers(headers or {})
    common.send_content(res, res_iter, "send_data")
  else
    if wsapi_env.STATUS == 404 then
      res.statusline = "HTTP/1.1 404"
      send_headers({ ["Content-Type"] = "text/html", ["Content-Length"] = (status and #status) or 0 })
      res:send_data(status)
    else
      local content = common.error_html(status)
      res.statusline = "HTTP/1.1 500"
      send_headers({ ["Content-Type"] = "text/html", ["Content-Length"] = #content})
      res:send_data(content)
    end
  end
end

-- Makes a WSAPI handler for a single WSAPI application
function _M.makeHandler (app_func, app_prefix, docroot, app_path, extra_vars)
  return function (req, res)
    return wsapihandler(req, res, app_func, app_prefix, docroot, app_path, extra_vars)
  end
end

-- Makes a generic WSAPI handler, that launches WSAPI application scripts
-- See the wsapi script for the possible values of the "params" table
function _M.makeGenericHandler(docroot, params, extra_vars)
  params = params or { isolated = true }
  return function (req, res)
    return wsapihandler(req, res, common.make_loader(params), nil, docroot, nil, extra_vars)
  end
end

return _M