// XXX lib/utils/tar.js and this file need to be rewritten.

// URL-to-cache folder mapping:
// : -> !
// @ -> _
// http://registry.npmjs.org/foo/version -> cache/http!/...
//

/*
fetching a URL:
1. Check for URL in inflight URLs.  If present, add cb, and return.
2. Acquire lock at {cache}/{sha(url)}.lock
   retries = {cache-lock-retries, def=3}
   stale = {cache-lock-stale, def=30000}
   wait = {cache-lock-wait, def=100}
3. if lock can't be acquired, then fail
4. fetch url, clear lock, call cbs

cache folders:
1. urls: http!/server.com/path/to/thing
2. c:\path\to\thing: file!/c!/path/to/thing
3. /path/to/thing: file!/path/to/thing
4. git@ private: git_github.com!npm/npm
5. git://public: git!/github.com/npm/npm
6. git+blah:// git-blah!/server.com/foo/bar

adding a folder:
1. tar into tmp/random/package.tgz
2. untar into tmp/random/contents/package, stripping one dir piece
3. tar tmp/random/contents/package to cache/n/v/package.tgz
4. untar cache/n/v/package.tgz into cache/n/v/package
5. rm tmp/random

Adding a url:
1. fetch to tmp/random/package.tgz
2. goto folder(2)

adding a name@version:
1. registry.get(name/version)
2. if response isn't 304, add url(dist.tarball)

adding a name@range:
1. registry.get(name)
2. Find a version that satisfies
3. add name@version

adding a local tarball:
1. untar to tmp/random/{blah}
2. goto folder(2)

adding a namespaced package:
1. lookup registry for @namespace
2. namespace_registry.get('name')
3. add url(namespace/latest.tarball)
*/

exports = module.exports = cache

cache.unpack = unpack
cache.clean = clean
cache.read = read

var npm = require("./npm.js")
  , fs = require("graceful-fs")
  , writeFileAtomic = require("write-file-atomic")
  , assert = require("assert")
  , rm = require("./utils/gently-rm.js")
  , readJson = require("read-package-json")
  , log = require("npmlog")
  , path = require("path")
  , asyncMap = require("slide").asyncMap
  , tar = require("./utils/tar.js")
  , fileCompletion = require("./utils/completion/file-completion.js")
  , deprCheck = require("./utils/depr-check.js")
  , addNamed = require("./cache/add-named.js")
  , addLocal = require("./cache/add-local.js")
  , addRemoteTarball = require("./cache/add-remote-tarball.js")
  , addRemoteGit = require("./cache/add-remote-git.js")
  , inflight = require("inflight")
  , realizePackageSpecifier = require("realize-package-specifier")
  , npa = require("npm-package-arg")
  , getStat = require("./cache/get-stat.js")
  , cachedPackageRoot = require("./cache/cached-package-root.js")
  , mapToRegistry = require("./utils/map-to-registry.js")

cache.usage = "npm cache add <tarball file>"
            + "\nnpm cache add <folder>"
            + "\nnpm cache add <tarball url>"
            + "\nnpm cache add <git url>"
            + "\nnpm cache add <name>@<version>"
            + "\nnpm cache ls [<path>]"
            + "\nnpm cache clean [<pkg>[@<version>]]"

cache.completion = function (opts, cb) {

  var argv = opts.conf.argv.remain
  if (argv.length === 2) {
    return cb(null, ["add", "ls", "clean"])
  }

  switch (argv[2]) {
    case "clean":
    case "ls":
      // cache and ls are easy, because the completion is
      // what ls_ returns anyway.
      // just get the partial words, minus the last path part
      var p = path.dirname(opts.partialWords.slice(3).join("/"))
      if (p === ".") p = ""
      return ls_(p, 2, cb)
    case "add":
      // Same semantics as install and publish.
      return npm.commands.install.completion(opts, cb)
  }
}

function cache (args, cb) {
  var cmd = args.shift()
  switch (cmd) {
    case "rm": case "clear": case "clean": return clean(args, cb)
    case "list": case "sl": case "ls": return ls(args, cb)
    case "add": return add(args, npm.prefix, cb)
    default: return cb("Usage: "+cache.usage)
  }
}

// if the pkg and ver are in the cache, then
// just do a readJson and return.
// if they're not, then fetch them from the registry.
function read (name, ver, forceBypass, cb) {
  assert(typeof name === "string", "must include name of module to install")
  assert(typeof cb === "function", "must include callback")

  if (forceBypass === undefined || forceBypass === null) forceBypass = true

  var root = cachedPackageRoot({name : name, version : ver})
  function c (er, data) {
    if (er) log.verbose("cache", "addNamed error for", name+"@"+ver, er)
    if (data) deprCheck(data)

    return cb(er, data)
  }

  if (forceBypass && npm.config.get("force")) {
    log.verbose("using force", "skipping cache")
    return addNamed(name, ver, null, c)
  }

  readJson(path.join(root, "package", "package.json"), function (er, data) {
    if (er && er.code !== "ENOENT" && er.code !== "ENOTDIR") return cb(er)

    if (data) {
      if (!data.name) return cb(new Error("No name provided"))
      if (!data.version) return cb(new Error("No version provided"))
    }

    if (er) return addNamed(name, ver, null, c)
    else c(er, data)
  })
}

function normalize (args) {
  var normalized = ""
  if (args.length > 0) {
    var a = npa(args[0])
    if (a.name) normalized = a.name
    if (a.rawSpec) normalized = [normalized, a.rawSpec].join("/")
    if (args.length > 1) normalized = [normalized].concat(args.slice(1)).join("/")
  }

  if (normalized.substr(-1) === "/") {
    normalized = normalized.substr(0, normalized.length - 1)
  }
  normalized = path.normalize(normalized)
  log.silly("ls", "normalized", normalized)

  return normalized
}

// npm cache ls [<path>]
function ls (args, cb) {
  var prefix = npm.config.get("cache")
  if (prefix.indexOf(process.env.HOME) === 0) {
    prefix = "~" + prefix.substr(process.env.HOME.length)
  }
  ls_(normalize(args), npm.config.get("depth"), function (er, files) {
    console.log(files.map(function (f) {
      return path.join(prefix, f)
    }).join("\n").trim())
    cb(er, files)
  })
}

// Calls cb with list of cached pkgs matching show.
function ls_ (req, depth, cb) {
  return fileCompletion(npm.cache, req, depth, cb)
}

// npm cache clean [<path>]
function clean (args, cb) {
  assert(typeof cb === "function", "must include callback")

  if (!args) args = []

  var f = path.join(npm.cache, normalize(args))
  if (f === npm.cache) {
    fs.readdir(npm.cache, function (er, files) {
      if (er) return cb()
      asyncMap( files.filter(function (f) {
                  return npm.config.get("force") || f !== "-"
                }).map(function (f) {
                  return path.join(npm.cache, f)
                })
              , rm, cb )
    })
  }
  else {
    rm(f, cb)
  }
}

// npm cache add <tarball-url>
// npm cache add <pkg> <ver>
// npm cache add <tarball>
// npm cache add <folder>
cache.add = function (pkg, ver, where, scrub, cb) {
  assert(typeof pkg === "string", "must include name of package to install")
  assert(typeof cb === "function", "must include callback")

  if (scrub) {
    return clean([], function (er) {
      if (er) return cb(er)
      add([pkg, ver], where, cb)
    })
  }
  return add([pkg, ver], where, cb)
}


var adding = 0
function add (args, where, cb) {
  // this is hot code.  almost everything passes through here.
  // the args can be any of:
  // ["url"]
  // ["pkg", "version"]
  // ["pkg@version"]
  // ["pkg", "url"]
  // This is tricky, because urls can contain @
  // Also, in some cases we get [name, null] rather
  // that just a single argument.

  var usage = "Usage:\n"
            + "    npm cache add <tarball-url>\n"
            + "    npm cache add <pkg>@<ver>\n"
            + "    npm cache add <tarball>\n"
            + "    npm cache add <folder>\n"
    , spec

  log.silly("cache add", "args", args)

  if (args[1] === undefined) args[1] = null

  // at this point the args length must ==2
  if (args[1] !== null) {
    spec = args[0]+"@"+args[1]
  } else if (args.length === 2) {
    spec = args[0]
  }

  log.verbose("cache add", "spec", spec)

  if (!spec) return cb(usage)

  if (adding <= 0) {
    npm.spinner.start()
  }
  adding++
  cb = afterAdd(cb)

  realizePackageSpecifier(spec, where, function (err, p) {
    if (err) return cb(err)

    log.silly("cache add", "parsed spec", p)

    switch (p.type) {
      case "local":
      case "directory":
        addLocal(p, null, cb)
        break
      case "remote":
        // get auth, if possible
        mapToRegistry(spec, npm.config, function (err, uri, auth) {
          if (err) return cb(err)

          addRemoteTarball(p.spec, {name : p.name}, null, auth, cb)
        })
        break
      case "git":
      case "hosted":
        addRemoteGit(p.rawSpec, cb)
        break
      default:
        if (p.name) return addNamed(p.name, p.spec, null, cb)

        cb(new Error("couldn't figure out how to install " + spec))
    }
  })
}

function unpack (pkg, ver, unpackTarget, dMode, fMode, uid, gid, cb) {
  if (typeof cb !== "function") cb = gid, gid = null
  if (typeof cb !== "function") cb = uid, uid = null
  if (typeof cb !== "function") cb = fMode, fMode = null
  if (typeof cb !== "function") cb = dMode, dMode = null

  read(pkg, ver, false, function (er) {
    if (er) {
      log.error("unpack", "Could not read data for %s", pkg + "@" + ver)
      return cb(er)
    }
    npm.commands.unbuild([unpackTarget], true, function (er) {
      if (er) return cb(er)
      tar.unpack( path.join(cachedPackageRoot({name : pkg, version : ver}), "package.tgz")
                , unpackTarget
                , dMode, fMode
                , uid, gid
                , cb )
    })
  })
}

function afterAdd (cb) { return function (er, data) {
  adding--
  if (adding <= 0) npm.spinner.stop()

  if (er || !data || !data.name || !data.version) return cb(er, data)
  log.silly("cache", "afterAdd", data.name+"@"+data.version)

  // Save the resolved, shasum, etc. into the data so that the next
  // time we load from this cached data, we have all the same info.
  var pj = path.join(cachedPackageRoot(data), "package", "package.json")

  var done = inflight(pj, cb)
  if (!done) return log.verbose("afterAdd", pj, "already in flight; not writing")
  log.verbose("afterAdd", pj, "not in flight; writing")

  getStat(function (er, cs) {
    if (er) return done(er)
    writeFileAtomic(pj, JSON.stringify(data), {chown : cs}, function (er) {
      if (!er) log.verbose("afterAdd", pj, "written")
      return done(er, data)
    })
  })
}}
