content: {-| Implementation of the RAPI client interface.
  
  -}
  
  {-
  
  Copyright (C) 2009, 2010, 2011, 2012, 2013 Google Inc.
  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are
  met:
  
  1. Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.
  
  2. Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
  documentation and/or other materials provided with the distribution.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  -}
  
  {-# LANGUAGE BangPatterns, CPP #-}
  
  module Ganeti.HTools.Backend.Rapi
    ( loadData
    , parseData
    ) where
  
  import Data.List (isPrefixOf)
  import Data.Maybe (fromMaybe)
  import Network.Curl
  import Network.Curl.Types ()
  import Control.Monad
  import Control.Monad.Fail (MonadFail)
  import Text.JSON (JSObject, fromJSObject, decodeStrict)
  import Text.JSON.Types (JSValue(..))
  import Text.Printf (printf)
  import System.FilePath
  import System.IO.Error (catchIOError)
  
  import Ganeti.BasicTypes
  import Ganeti.Types (Hypervisor(..))
  import Ganeti.HTools.Loader
  import Ganeti.HTools.Types
  import Ganeti.JSON (loadJSArray, JSRecord, tryFromObj, fromJVal, maybeFromObj,
                      fromJResult, tryArrayMaybeFromObj, readEitherString,
                      fromObjWithDefault, asJSObject)
  import qualified Ganeti.HTools.Group as Group
  import qualified Ganeti.HTools.Node as Node
  import qualified Ganeti.HTools.Instance as Instance
  import qualified Ganeti.HTools.Container as Container
  import qualified Ganeti.Constants as C
  
  {-# ANN module "HLint: ignore Eta reduce" #-}
  
  -- | File method prefix.
  filePrefix :: String
  filePrefix = "file://"
  
  -- | Read an URL via curl and return the body if successful.
  getUrl :: (MonadFail m) => String -> IO (m String)
  
  -- | Connection timeout (when using non-file methods).
  connTimeout :: Long
  connTimeout = 15
  
  -- | The default timeout for queries (when using non-file methods).
  queryTimeout :: Long
  queryTimeout = 60
  
  -- | The curl options we use.
  curlOpts :: [CurlOption]
  curlOpts = [ CurlSSLVerifyPeer False
             , CurlSSLVerifyHost 0
             , CurlTimeout queryTimeout
             , CurlConnectTimeout connTimeout
             ]
  
  getUrl url = do
    (code, !body) <- curlGetString url curlOpts
    return (case code of
              CurlOK -> return body
              _ -> fail $ printf "Curl error for '%s', error %s"
                   url (show code))
  
  -- | Helper to convert I/O errors in 'Bad' values.
  ioErrToResult :: IO a -> IO (Result a)
  ioErrToResult ioaction =
    catchIOError (liftM Ok ioaction) (return . Bad . show)
  
  -- | Append the default port if not passed in.
  formatHost :: String -> String
  formatHost master =
    if ':' `elem` master
      then  master
      else "https://" ++ master ++ ":" ++ show C.defaultRapiPort
  
  -- | Parse a instance list in JSON format.
  getInstances :: NameAssoc
               -> String
               -> Result [(String, Instance.Instance)]
  getInstances ktn body =
    loadJSArray "Parsing instance data" body >>=
    mapM (parseInstance ktn . fromJSObject)
  
  -- | Parse a node list in JSON format.
  getNodes :: NameAssoc -> String -> Result [(String, Node.Node)]
  getNodes ktg body = loadJSArray "Parsing node data" body >>=
                      mapM (parseNode ktg . fromJSObject)
  
  -- | Parse a group list in JSON format.
  getGroups :: String -> Result [(String, Group.Group)]
  getGroups body = loadJSArray "Parsing group data" body >>=
                   mapM (parseGroup . fromJSObject)
  
  -- | Construct an instance from a JSON object.
  parseInstance :: NameAssoc
                -> JSRecord
                -> Result (String, Instance.Instance)
  parseInstance ktn a = do
    name <- tryFromObj "Parsing new instance" a "name"
    let owner_name = "Instance '" ++ name ++ "', error while parsing data"
    let extract s x = tryFromObj owner_name x s
    disk <- extract "disk_usage" a
    dsizes <- extract "disk.sizes" a
    dspindles <- tryArrayMaybeFromObj owner_name a "disk.spindles"
    beparams <- liftM fromJSObject (extract "beparams" a)
    omem <- extract "oper_ram" a
    mem <- case omem of
             JSRational _ _ -> annotateResult owner_name (fromJVal omem)
             _ -> extract "memory" beparams `mplus` extract "maxmem" beparams
    vcpus <- extract "vcpus" beparams
    pnode <- extract "pnode" a >>= lookupNode ktn name
    snodes <- extract "snodes" a
    snode <- case snodes of
               [] -> return Node.noSecondary
               x:_ -> readEitherString x >>= lookupNode ktn name
    running <- extract "status" a
    tags <- extract "tags" a
    auto_balance <- extract "auto_balance" beparams
    dt <- extract "disk_template" a
    su <- extract "spindle_use" beparams
    -- Not forthcoming by default.
    forthcoming <- extract "forthcoming" a `orElse` Ok False
    let disks = zipWith Instance.Disk dsizes dspindles
    let inst = Instance.create name mem disk disks vcpus running tags
               auto_balance pnode snode dt su [] forthcoming
    return (name, inst)
  
  -- | Construct a node from a JSON object.
  parseNode :: NameAssoc -> JSRecord -> Result (String, Node.Node)
  parseNode ktg a = do
    name <- tryFromObj "Parsing new node" a "name"
    let desc = "Node '" ++ name ++ "', error while parsing data"
        extract key = tryFromObj desc a key
        extractDef def key = fromObjWithDefault a key def
    offline <- extract "offline"
    drained <- extract "drained"
    vm_cap  <- annotateResult desc $ maybeFromObj a "vm_capable"
    let vm_cap' = fromMaybe True vm_cap
    ndparams <- extract "ndparams" >>= asJSObject
    excl_stor <- tryFromObj desc (fromJSObject ndparams) "exclusive_storage"
    guuid   <- annotateResult desc $ maybeFromObj a "group.uuid"
    guuid' <-  lookupGroup ktg name (fromMaybe defaultGroupID guuid)
    let live = not offline && vm_cap'
        lvextract def = eitherLive live def . extract
        lvextractDef def = eitherLive live def . extractDef def
    sptotal <- if excl_stor
               then lvextract 0 "sptotal"
               else tryFromObj desc (fromJSObject ndparams) "spindle_count"
    spfree <- lvextractDef 0 "spfree"
    mtotal <- lvextract 0.0 "mtotal"
    mnode <- lvextract 0 "mnode"
    mfree <- lvextract 0 "mfree"
    dtotal <- lvextractDef 0.0 "dtotal"
    dfree <- lvextractDef 0 "dfree"
    ctotal <- lvextract 0.0 "ctotal"
    cnos <- lvextract 0 "cnos"
    tags <- extract "tags"
    let node = flip Node.setNodeTags tags $
               Node.create name mtotal mnode mfree dtotal dfree ctotal cnos
               (not live || drained) sptotal spfree guuid' excl_stor
    return (name, node)
  
  -- | Construct a group from a JSON object.
  parseGroup :: JSRecord -> Result (String, Group.Group)
  parseGroup a = do
    name <- tryFromObj "Parsing new group" a "name"
    let extract s = tryFromObj ("Group '" ++ name ++ "'") a s
    uuid <- extract "uuid"
    apol <- extract "alloc_policy"
    ipol <- extract "ipolicy"
    tags <- extract "tags"
    -- TODO: parse networks to which this group is connected
    return (uuid, Group.create name uuid apol [] ipol tags)
  
  -- | Parse cluster data from the info resource.
  parseCluster :: JSObject JSValue -> Result ([String], IPolicy,
                                              String, Hypervisor)
  parseCluster obj = do
    let obj' = fromJSObject obj
        extract s = tryFromObj "Parsing cluster data" obj' s
    master <- extract "master"
    tags <- extract "tags"
    ipolicy <- extract "ipolicy"
    hypervisor <- extract "default_hypervisor"
    return (tags, ipolicy, master, hypervisor)
  
  -- | Loads the raw cluster data from an URL.
  readDataHttp :: String -- ^ Cluster or URL to use as source
               -> IO (Result String, Result String, Result String, Result String)
  readDataHttp master = do
    let url = formatHost master
    group_body <- getUrl $ printf "%s/2/groups?bulk=1" url
    node_body <- getUrl $ printf "%s/2/nodes?bulk=1" url
    inst_body <- getUrl $ printf "%s/2/instances?bulk=1" url
    info_body <- getUrl $ printf "%s/2/info" url
    return (group_body, node_body, inst_body, info_body)
  
  -- | Loads the raw cluster data from the filesystem.
  readDataFile:: String -- ^ Path to the directory containing the files
               -> IO (Result String, Result String, Result String, Result String)
  readDataFile path = do
    group_body <- ioErrToResult . readFile $ path </> "groups.json"
    node_body <- ioErrToResult . readFile $ path </> "nodes.json"
    inst_body <- ioErrToResult . readFile $ path </> "instances.json"
    info_body <- ioErrToResult . readFile $ path </> "info.json"
    return (group_body, node_body, inst_body, info_body)
  
  -- | Loads data via either 'readDataFile' or 'readDataHttp'.
  readData :: String -- ^ URL to use as source
           -> IO (Result String, Result String, Result String, Result String)
  readData url =
    if filePrefix `isPrefixOf` url
      then readDataFile (drop (length filePrefix) url)
      else readDataHttp url
  
  -- | Builds the cluster data from the raw Rapi content.
  parseData :: (Result String, Result String, Result String, Result String)
            -> Result ClusterData
  parseData (group_body, node_body, inst_body, info_body) = do
    group_data <- group_body >>= getGroups
    let (group_names, group_idx) = assignIndices group_data
    node_data <- node_body >>= getNodes group_names
    let (node_names, node_idx) = assignIndices node_data
    inst_data <- inst_body >>= getInstances node_names
    let (_, inst_idx) = assignIndices inst_data
    (tags, ipolicy, master, hypervisor) <-
      info_body >>=
      (fromJResult "Parsing cluster info" . decodeStrict) >>=
      parseCluster
    node_idx' <- setMaster node_names node_idx master
    let node_idx'' = Container.map (`Node.setHypervisor` hypervisor) node_idx'
    return (ClusterData group_idx node_idx'' inst_idx tags ipolicy)
  
  -- | Top level function for data loading.
  loadData :: String -- ^ Cluster or URL to use as source
           -> IO (Result ClusterData)
  loadData = fmap parseData . readData
  