module.exports = owner

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

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)
  }
  var un = encodeURIComponent(npm.config.get("username"))
  switch (argv[2]) {
    case "ls":
      if (argv.length > 3) return cb()
      else return registry.get("/-/short", cb)

    case "rm":
      if (argv.length > 3) {
        var theUser = encodeURIComponent(argv[3])
          , uri = "/-/by-user/"+theUser+"|"+un
        console.error(uri)
        return registry.get(uri, 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) {
        var theUser = encodeURIComponent(argv[3])
          , uri = "/-/by-user/"+theUser+"|"+un
        console.error(uri)
        return registry.get(uri, 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 registry.get("/-/users", function (er, list) {
        if (er) return cb()
        return cb(null, Object.keys(list).filter(function (n) {
          return n !== un
        }))
      })

    default:
      return cb()
  }
}

var npm = require("./npm.js")
  , registry = npm.registry
  , log = require("npmlog")
  , readJson = require("read-package-json")

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 cb(owner.usage)
  registry.get(pkg, 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 (!pkg) 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) 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, null, 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) {
    registry.get("/-/user/org.couchdb.user:"+user, 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 }
    registry.get(pkg, function (er, data) {
      if (er) {
        log.error("owner mutate", "Error getting package data for %s", pkg)
        return cb(er)
      }
      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
             }
      registry.request("PUT"
          , pkg+"/-rev/"+data._rev, data
          , 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")
        }
        cb(er, data)
      })
    })
  }
}

function readLocalPkg (cb) {
  if (npm.config.get("global")) return cb()
  var path = require("path")
  readJson(path.resolve(npm.prefix, "package.json"), function (er, d) {
    return cb(er, d && d.name)
  })
}

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