module.exports = owner

owner.usage = "npm owner add <username> <pkg>"
            + "\nnpm owner rm <username> <pkg>"
            + "\nnpm owner ls <pkg>"

var npm = require("./npm.js")
  , log = require("npmlog")
  , mapToRegistry = require("./utils/map-to-registry.js")
  , readLocalPkg = require("./utils/read-local-package.js")

owner.completion = function (opts, cb) {
  var argv = opts.conf.argv.remain
  if (argv.length > 4) return cb()
  if (argv.length <= 2) {
    var subs = ["add", "rm"]
    if (opts.partialWord === "l") subs.push("ls")
    else subs.push("ls", "list")
    return cb(null, subs)
  }

  npm.commands.whoami([], true, function (er, username) {
    if (er) return cb()

    var un = encodeURIComponent(username)
    var byUser, theUser
    switch (argv[2]) {
      case "ls":
        // FIXME: there used to be registry completion here, but it stopped
        // making sense somewhere around 50,000 packages on the registry
        return cb()

      case "rm":
        if (argv.length > 3) {
          theUser = encodeURIComponent(argv[3])
          byUser = "-/by-user/" + theUser + "|" + un
          return mapToRegistry(byUser, npm.config, function (er, uri, auth) {
            if (er) return cb(er)

            console.error(uri)
            npm.registry.get(uri, { auth : auth }, function (er, d) {
              if (er) return cb(er)
              // return the intersection
              return cb(null, d[theUser].filter(function (p) {
                // kludge for server adminery.
                return un === "isaacs" || d[un].indexOf(p) === -1
              }))
            })
          })
        }
        // else fallthrough
      case "add":
        if (argv.length > 3) {
          theUser = encodeURIComponent(argv[3])
          byUser = "-/by-user/" + theUser + "|" + un
          return mapToRegistry(byUser, npm.config, function (er, uri, auth) {
            if (er) return cb(er)

            console.error(uri)
            npm.registry.get(uri, { auth : auth }, function (er, d) {
              console.error(uri, er || d)
              // return mine that they're not already on.
              if (er) return cb(er)
              var mine = d[un] || []
                , theirs = d[theUser] || []
              return cb(null, mine.filter(function (p) {
                return theirs.indexOf(p) === -1
              }))
            })
          })
        }
        // just list all users who aren't me.
        return mapToRegistry("-/users", npm.config, function (er, uri, auth) {
          if (er) return cb(er)

          npm.registry.get(uri, { auth : auth }, function (er, list) {
            if (er) return cb()
            return cb(null, Object.keys(list).filter(function (n) {
              return n !== un
            }))
          })
        })

      default:
        return cb()
    }
  })
}

function owner (args, cb) {
  var action = args.shift()
  switch (action) {
    case "ls": case "list": return ls(args[0], cb)
    case "add": return add(args[0], args[1], cb)
    case "rm": case "remove": return rm(args[0], args[1], cb)
    default: return unknown(action, cb)
  }
}

function ls (pkg, cb) {
  if (!pkg) return readLocalPkg(function (er, pkg) {
    if (er) return cb(er)
    if (!pkg) return cb(owner.usage)
    ls(pkg, cb)
  })

  mapToRegistry(pkg, npm.config, function (er, uri, auth) {
    if (er) return cb(er)

    npm.registry.get(uri, { auth : auth }, function (er, data) {
      var msg = ""
      if (er) {
        log.error("owner ls", "Couldn't get owner data", pkg)
        return cb(er)
      }
      var owners = data.maintainers
      if (!owners || !owners.length) msg = "admin party!"
      else msg = owners.map(function (o) {
        return o.name + " <" + o.email + ">"
      }).join("\n")
      console.log(msg)
      cb(er, owners)
    })
  })
}

function add (user, pkg, cb) {
  if (!user) return cb(owner.usage)
  if (!pkg) return readLocalPkg(function (er, pkg) {
    if (er) return cb(er)
    if (!pkg) return cb(new Error(owner.usage))
    add(user, pkg, cb)
  })

  log.verbose("owner add", "%s to %s", user, pkg)
  mutate(pkg, user, function (u, owners) {
    if (!owners) owners = []
    for (var i = 0, l = owners.length; i < l; i ++) {
      var o = owners[i]
      if (o.name === u.name) {
        log.info( "owner add"
                , "Already a package owner: " + o.name + " <" + o.email + ">")
        return false
      }
    }
    owners.push(u)
    return owners
  }, cb)
}

function rm (user, pkg, cb) {
  if (!pkg) return readLocalPkg(function (er, pkg) {
    if (er) return cb(er)
    if (!pkg) return cb(new Error(owner.usage))
    rm(user, pkg, cb)
  })

  log.verbose("owner rm", "%s from %s", user, pkg)
  mutate(pkg, user, function (u, owners) {
    var found = false
      , m = owners.filter(function (o) {
          var match = (o.name === user)
          found = found || match
          return !match
        })
    if (!found) {
      log.info("owner rm", "Not a package owner: " + user)
      return false
    }
    if (!m.length) return new Error(
      "Cannot remove all owners of a package.  Add someone else first.")
    return m
  }, cb)
}

function mutate (pkg, user, mutation, cb) {
  if (user) {
    var byUser = "-/user/org.couchdb.user:" + user
    mapToRegistry(byUser, npm.config, function (er, uri, auth) {
      if (er) return cb(er)

      npm.registry.get(uri, { auth : auth }, mutate_)
    })
  } else {
    mutate_(null, null)
  }

  function mutate_ (er, u) {
    if (!er && user && (!u || u.error)) er = new Error(
      "Couldn't get user data for " + user + ": " + JSON.stringify(u))

    if (er) {
      log.error("owner mutate", "Error getting user data for %s", user)
      return cb(er)
    }

    if (u) u = { "name" : u.name, "email" : u.email }
    mapToRegistry(pkg, npm.config, function (er, uri, auth) {
      if (er) return cb(er)

      npm.registry.get(uri, { auth : auth }, function (er, data) {
        if (er) {
          log.error("owner mutate", "Error getting package data for %s", pkg)
          return cb(er)
        }

        // save the number of maintainers before mutation so that we can figure
        // out if maintainers were added or removed
        var beforeMutation = data.maintainers.length

        var m = mutation(u, data.maintainers)
        if (!m) return cb() // handled
        if (m instanceof Error) return cb(m) // error

        data = {
          _id : data._id,
          _rev : data._rev,
          maintainers : m
        }
        var dataPath = pkg.replace("/", "%2f") + "/-rev/" + data._rev
        mapToRegistry(dataPath, npm.config, function (er, uri, auth) {
          if (er) return cb(er)

          var params = {
            method : "PUT",
            body : data,
            auth : auth
          }
          npm.registry.request(uri, params, function (er, data) {
            if (!er && data.error) {
              er = new Error("Failed to update package metadata: "+JSON.stringify(data))
            }

            if (er) {
              log.error("owner mutate", "Failed to update package metadata")
            }
            else if (m.length > beforeMutation) {
              console.log("+ %s (%s)", user, pkg)
            }
            else if (m.length < beforeMutation) {
              console.log("- %s (%s)", user, pkg)
            }

            cb(er, data)
          })
        })
      })
    })
  }
}

function unknown (action, cb) {
  cb("Usage: \n" + owner.usage)
}