--[[
LuCI - Lua Configuration Interface
Copyright 2019 lisaac <https://github.com/lisaac/luci-lib-docker>
]]--
require "nixio.util"
require "luci.util"
local jsonc = require "luci.jsonc"
local nixio = require "nixio"
local ltn12 = require "luci.ltn12"
local fs = require "nixio.fs"

local urlencode = luci.util.urlencode or luci.http and luci.http.protocol and luci.http.protocol.urlencode
local json_stringify = jsonc.stringify
local json_parse = jsonc.parse

local chunksource = function(sock, buffer)
  buffer = buffer or ""
  return function()
    local output
    local _, endp, count = buffer:find("^([0-9a-fA-F]+)\r\n")
    while not count do
      local newblock, code = sock:recv(1024)
      if not newblock then return nil, code end
      buffer = buffer .. newblock
      _, endp, count = buffer:find("^([0-9a-fA-F]+)\r\n")
    end
    count = tonumber(count, 16)
    if not count then
      return nil, -1, "invalid encoding"
    elseif count == 0 then -- finial
      return nil
    elseif count <= #buffer - endp then
      --data >= count
      output = buffer:sub(endp + 1, endp + count)
      if count == #buffer - endp then          -- [data]
        buffer = buffer:sub(endp + count + 1)
        count, code = sock:recvall(2) --read \r\n
        if not count then return nil, code end
      elseif count + 1 == #buffer - endp then  -- [data]\r
        buffer = buffer:sub(endp + count + 2)
        count, code = sock:recvall(1) --read \n
        if not count then return nil, code end
      else                                     -- [data]\r\n[count]\r\n[data]...
        buffer = buffer:sub(endp + count + 3) -- cut buffer
      end
      return output
    else
      -- data < count
      output = buffer:sub(endp + 1, endp + count)
      buffer = buffer:sub(endp + count + 1)
      local remain, code = sock:recvall(count - #output) --need read remaining
      if not remain then return nil, code end
      output = output .. remain
      count, code = sock:recvall(2) --read \r\n
      if not count then return nil, code end
      return output
    end
  end
end

local chunksink = function (sock)
  return function(chunk, err)
    if not chunk then
      return sock:writeall("0\r\n\r\n")
    else
      return sock:writeall(("%X\r\n%s\r\n"):format(#chunk, tostring(chunk)))
    end
  end
end

local docker_stream_filter = function(buffer)
  buffer = buffer or ""
  if #buffer < 8 then
    return ""
  end
  local stream_type = ((string.byte(buffer, 1) == 1) and "stdout") or ((string.byte(buffer, 1) == 2) and "stderr") or ((string.byte(buffer, 1) == 0) and "stdin") or "stream_err"
  local valid_length =
    tonumber(string.byte(buffer, 5)) * 256 * 256 * 256 + tonumber(string.byte(buffer, 6)) * 256 * 256 + tonumber(string.byte(buffer, 7)) * 256 + tonumber(string.byte(buffer, 8))
  if valid_length > #buffer + 8 then
    return ""
  end
  return stream_type .. ": " .. string.sub(buffer, 9, valid_length + 8)
  -- return string.sub(buffer, 9, valid_length + 8)
end

local open_socket = function(req_options)
  local socket
  if type(req_options) ~= "table" then return socket end
  if req_options.socket_path then
    socket = nixio.socket("unix", "stream")
    if socket:connect(req_options.socket_path) ~= true then return nil end
  elseif req_options.host and req_options.port then
    socket = nixio.connect(req_options.host, req_options.port)
  end
  if socket then
    return socket
  else
    return nil
  end
end

local send_http_socket = function(options, docker_socket, req_header, req_body, callback)
  if docker_socket:send(req_header) == 0 then
    return {
      headers={code=498,message="bad path", protocol="HTTP/1.1"},
      body={message="can\'t send data to socket"}
    }
  end

  if req_body and type(req_body) == "function" and req_header and req_header:match("chunked") then
    -- chunked send
    req_body(chunksink(docker_socket))
  elseif req_body and type(req_body) == "function" then
    -- normal send by req_body function
    req_body(docker_socket)
  elseif req_body and type(req_body) == "table" then
    -- json
    docker_socket:send(json_stringify(req_body))
    if options.debug then io.popen("echo '".. json_stringify(req_body) .. "' >> " .. options.debug_path) end
  elseif req_body then
    docker_socket:send(req_body)
    if options.debug then io.popen("echo '".. req_body .. "' >> " .. options.debug_path) end
  end

  local linesrc = docker_socket:linesource()
  -- read socket using source http://w3.impa.br/~diego/software/luasocket/ltn12.html
  --http://lua-users.org/wiki/FiltersSourcesAndSinks
  -- handle response header
  local line = linesrc()
  if not line then
    docker_socket:close()
    return {
      headers = {code=499, message="bad socket path", protocol="HTTP/1.1"},
      body = {message="no data receive from socket"}
    }
  end
  local response = {code = 0, headers = {}, body = {}}

  local p, code, msg = line:match("^([%w./]+) ([0-9]+) (.*)")
  response.protocol = p
  response.code = tonumber(code)
  response.message = msg
  line = linesrc()
  while line and line ~= "" do
    local key, val = line:match("^([%w-]+)%s?:%s?(.*)")
    if key and key ~= "Status" then
      if type(response.headers[key]) == "string" then
        response.headers[key] = {response.headers[key], val}
      elseif type(response.headers[key]) == "table" then
        response.headers[key][#response.headers[key] + 1] = val
      else
        response.headers[key] = val
      end
    end
    line = linesrc()
  end
  -- handle response body
  local body_buffer = linesrc(true)
  response.body = {}
  if type(callback) ~= "function" then
    if response.headers["Transfer-Encoding"] == "chunked" then
      local source = chunksource(docker_socket, body_buffer)
      code = ltn12.pump.all(source, (ltn12.sink.table(response.body))) and response.code or 555
      response.code = code
    else
      local body_source = ltn12.source.cat(ltn12.source.string(body_buffer), docker_socket:blocksource())
      code = ltn12.pump.all(body_source, (ltn12.sink.table(response.body))) and response.code or 555
      response.code = code
    end
  else
    if response.headers["Transfer-Encoding"] == "chunked" then
      local source = chunksource(docker_socket, body_buffer)
      callback(response, source)
    else
      local body_source = ltn12.source.cat(ltn12.source.string(body_buffer), docker_socket:blocksource())
      callback(response, body_source)
    end
  end
  docker_socket:close()
  return response
end

local gen_header = function(options, http_method, api_group, api_action, name_or_id, request)
  local header, query, path
  name_or_id = (name_or_id ~= "") and name_or_id or nil

  if request and type(request.query) == "table" then
    local k, v
    for k, v in pairs(request.query) do
      if type(v) == "table" then
        query = (query and query .. "&" or "?") .. k .. "=" .. urlencode(json_stringify(v))
      elseif type(v) == "boolean" then
        query = (query and query .. "&" or "?") .. k .. "=" .. (v and "true" or "false")
      elseif type(v) == "number" or type(v) == "string" then
        query = (query and query .. "&" or "?") .. k .. "=" .. v
      end
    end
  end
  path = (api_group and ("/" .. api_group) or "") .. (name_or_id and ("/" .. name_or_id) or "") .. (api_action and ("/" .. api_action) or "") .. (query or "")
  header = (http_method or "GET") .. " " .. path .. " " .. options.protocol .. "\r\n"
  header = header .. "Host: " .. options.host .. "\r\n"
  header = header .. "User-Agent: " .. options.user_agent .. "\r\n"
  header = header .. "Connection: close\r\n"

  if request and type(request.header) == "table" then
    local k, v
    for k, v in pairs(request.header) do
      header = header .. k .. ": " .. v .. "\r\n"
    end
  end

  -- when requst_body is function, we need to custom header using custom header
  if request and request.body and type(request.body) == "function" then
    if not header:match("Content-Length:") then
      header = header .. "Transfer-Encoding: chunked\r\n"
    end
  elseif http_method == "POST" and request and request.body and type(request.body) == "table" then
    local conetnt_json = json_stringify(request.body)
    header = header .. "Content-Type: application/json\r\n"
    header = header .. "Content-Length: " .. #conetnt_json .. "\r\n"
  elseif request and request.body and type(request.body) == "string" then
    header = header .. "Content-Length: " .. #request.body .. "\r\n"
  end
  header = header .. "\r\n"
  if options.debug then io.popen("echo '".. header .. "' >> " .. options.debug_path) end
  return header
end

local call_docker = function(options, http_method, api_group, api_action, name_or_id, request, callback)
  local req_options = setmetatable({}, {__index = options})

  local req_header = gen_header(req_options, http_method, api_group, api_action, name_or_id, request)
  local req_body = request and request.body or nil
  local docker_socket = open_socket(req_options)

  if docker_socket then
    return send_http_socket(options, docker_socket, req_header, req_body, callback)
  else
    return {
      headers = {code=497, message="bad socket path or host", protocol="HTTP/1.1"},
      body = {message="can\'t connect to socket"}
    }
  end
end

local gen_api = function(_table, http_method, api_group, api_action)
  local _api_action
  if api_action == "get_archive" or api_action == "put_archive" then
    _api_action = "archive"
  elseif api_action == "df" then
    _api_action = "system/df"
  elseif api_action ~= "list" and api_action ~= "inspect" and api_action ~= "remove" then
    _api_action = api_action
  elseif (api_group == "containers" or api_group == "images" or api_group == "exec") and (api_action == "list" or api_action == "inspect") then
    _api_action = "json"
  end

  local fp = function(self, request, callback)
    local name_or_id = request and (request.name or request.id or request.name_or_id) or nil
    if api_action == "list" then
      if (name_or_id ~= "" and name_or_id ~= nil) then
        if api_group == "images" then
          name_or_id = nil
        else
          request.query = request and request.query or {}
          request.query.filters = request.query.filters or {}
          request.query.filters.name = request.query.filters.name or {}
          request.query.filters.name[#request.query.filters.name + 1] = name_or_id
          name_or_id = nil
        end
      end
    elseif api_action == "create" then
      if (name_or_id ~= "" and name_or_id ~= nil) then
        request.query = request and request.query or {}
        request.query.name = request.query.name or name_or_id
        name_or_id = nil
      end
    elseif api_action == "logs" then
      local body_buffer = ""
      local response = call_docker(self.options, http_method, api_group, _api_action, name_or_id, request, callback)
      if response.code >= 200 and response.code < 300 then
        for i, v in ipairs(response.body) do
          body_buffer = body_buffer .. docker_stream_filter(response.body[i])
        end
        response.body = body_buffer
      end
      return response
    end
    local response = call_docker(self.options, http_method, api_group, _api_action, name_or_id, request, callback)
    if response.headers and response.headers["Content-Type"] == "application/json" then
      if #response.body == 1 then
        response.body = json_parse(response.body[1])
      else
        local tmp = {}
        for _, v in ipairs(response.body) do
          tmp[#tmp+1] = json_parse(v)
        end
        response.body = tmp
      end
    end
    return response
  end

  if api_group then
    _table[api_group][api_action] = fp
  else
    _table[api_action] = fp
  end
end

local _docker = {containers = {}, exec = {}, images = {}, networks = {}, volumes = {}}

gen_api(_docker, "GET", "containers", "list")
gen_api(_docker, "POST", "containers", "create")
gen_api(_docker, "GET", "containers", "inspect")
gen_api(_docker, "GET", "containers", "top")
gen_api(_docker, "GET", "containers", "logs")
gen_api(_docker, "GET", "containers", "changes")
gen_api(_docker, "GET", "containers", "stats")
gen_api(_docker, "POST", "containers", "resize")
gen_api(_docker, "POST", "containers", "start")
gen_api(_docker, "POST", "containers", "stop")
gen_api(_docker, "POST", "containers", "restart")
gen_api(_docker, "POST", "containers", "kill")
gen_api(_docker, "POST", "containers", "update")
gen_api(_docker, "POST", "containers", "rename")
gen_api(_docker, "POST", "containers", "pause")
gen_api(_docker, "POST", "containers", "unpause")
gen_api(_docker, "POST", "containers", "update")
gen_api(_docker, "DELETE", "containers", "remove")
gen_api(_docker, "POST", "containers", "prune")
gen_api(_docker, "POST", "containers", "exec")
gen_api(_docker, "POST", "exec", "start")
gen_api(_docker, "POST", "exec", "resize")
gen_api(_docker, "GET", "exec", "inspect")
gen_api(_docker, "GET", "containers", "get_archive")
gen_api(_docker, "PUT", "containers", "put_archive")
gen_api(_docker, "GET", "containers", "export")
-- TODO: attch

gen_api(_docker, "GET", "images", "list")
gen_api(_docker, "POST", "images", "create")
gen_api(_docker, "GET", "images", "inspect")
gen_api(_docker, "GET", "images", "history")
gen_api(_docker, "POST", "images", "tag")
gen_api(_docker, "DELETE", "images", "remove")
gen_api(_docker, "GET", "images", "search")
gen_api(_docker, "POST", "images", "prune")
gen_api(_docker, "GET", "images", "get")
gen_api(_docker, "POST", "images", "load")

gen_api(_docker, "GET", "networks", "list")
gen_api(_docker, "GET", "networks", "inspect")
gen_api(_docker, "DELETE", "networks", "remove")
gen_api(_docker, "POST", "networks", "create")
gen_api(_docker, "POST", "networks", "connect")
gen_api(_docker, "POST", "networks", "disconnect")
gen_api(_docker, "POST", "networks", "prune")

gen_api(_docker, "GET", "volumes", "list")
gen_api(_docker, "GET", "volumes", "inspect")
gen_api(_docker, "DELETE", "volumes", "remove")
gen_api(_docker, "POST", "volumes", "create")

gen_api(_docker, "GET", nil, "events")
gen_api(_docker, "GET", nil, "version")
gen_api(_docker, "GET", nil, "info")
gen_api(_docker, "GET", nil, "_ping")
gen_api(_docker, "GET", nil, "df")

function _docker.new(options)
  local docker = {}
  local _options = options or {}
  docker.options = {
    socket_path = _options.socket_path or nil,
    host = _options.socket_path and "localhost" or _options.host,
    port = not _options.socket_path and _options.port or nil,
    tls = _options.tls or nil,
    tls_cacert = _options.tls and _options.tls_cacert or nil,
    tls_cert = _options.tls and _options.tls_cert or nil,
    tls_key = _options.tls and _options.tls_key or nil,
    version = _options.version or "v1.40",
    user_agent = _options.user_agent or "LuCI",
    protocol = _options.protocol or "HTTP/1.1",
    debug = _options.debug or false,
    debug_path = _options.debug and _options.debug_path or nil
  }
  setmetatable(
    docker,
    {
      __index = function(t, key)
        if _docker[key] ~= nil then
          return _docker[key]
        else
          return _docker.containers[key]
        end
      end
    }
  )
  setmetatable(
    docker.containers,
    {
      __index = function(t, key)
        if key == "options" then
          return docker.options
        end
      end
    }
  )
  setmetatable(
    docker.networks,
    {
      __index = function(t, key)
        if key == "options" then
          return docker.options
        end
      end
    }
  )
  setmetatable(
    docker.images,
    {
      __index = function(t, key)
        if key == "options" then
          return docker.options
        end
      end
    }
  )
  setmetatable(
    docker.volumes,
    {
      __index = function(t, key)
        if key == "options" then
          return docker.options
        end
      end
    }
  )
  setmetatable(
    docker.exec,
    {
      __index = function(t, key)
        if key == "options" then
          return docker.options
        end
      end
    }
  )
  return docker
end

return _docker
