# ----------------------------------------------------------------------
#  P2P: central authority for all P2P activities
#
#  This server is the "superpeer" that all workers contact first
#  to join the network.  Clients and workers also contact the authority
#  to handle payments for services.
# ----------------------------------------------------------------------
#  Michael McLennan (mmclennan@purdue.edu)
# ======================================================================
#  Copyright (c) 2008  Purdue Research Foundation
#
#  See the file "license.terms" for information on usage and
#  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
# ======================================================================

# recognize other library files in this same directory
set dir [file dirname [info script]]
lappend auto_path $dir

# handle log file for this authority
log channel debug on
log channel system on

# ======================================================================
#  WORKER OPTIONS
# ======================================================================

# set of connections for authority servers
set worker_options(authority_hosts) \
    {127.0.0.1:9001 127.0.0.1:9002 127.0.0.1:9003}

# register with the central authority at this frequency
set worker_options(time_between_authority_checks) 60000

# workers should try to connect with this many other peers
set worker_options(max_peer_connections) 4

# ======================================================================
#  PROTOCOL: hubzero:authority<-worker/1
#
#  The worker initiates communication with the authority by sending
#  these messages to the authority to request information about
#  other peers.
# ======================================================================
p2p::protocol::register hubzero:authority<-worker/1 {

    # ------------------------------------------------------------------
    #  INCOMING: listening <port>
    #  Workers use this to tell the authority what port they're
    #  listening on.  Other workers should connect to this port.
    # ------------------------------------------------------------------
    define listening {port} {
        global client2address workers
        variable handler
        variable cid

        # register this address on the list of workers
        set addr "$client2address($cid):$port"
        set workers($addr) "--"

        # name this connection for easier debugging
        $handler connectionName $cid $addr

        return ""
    }

    # ------------------------------------------------------------------
    #  INCOMING: peers
    # ------------------------------------------------------------------
    define peers {} {
        global workers
        return [list peers [array names workers]]
    }
}

# ======================================================================
#  PROTOCOL: hubzero:authority<-foreman/1
#
#  The foreman initiates communication with the authority by sending
#  these messages to request information about workers, to estimate
#  requirements for a job, to put funds in escrow, and to finalize
#  the transaction.
# ======================================================================
p2p::protocol::register hubzero:authority<-foreman/1 {
    # ------------------------------------------------------------------
    #  INCOMING: workers
    #  Foremen use this to request the list of known workers, and then
    #  pick one worker to act as their connection to the P2P network.
    # ------------------------------------------------------------------
    define workers {} {
        global workers
        return [list workers [array names workers]]
    }
}

# ======================================================================
# set up a server at the first open port above 9001
set server [p2p::server \
    -port 9001? \
    -protocols {hubzero:authority<-worker hubzero:authority<-foreman} \
    -servername authority \
    -onconnect authority_client_address \
    -onprotocol authority_client_protocol \
]

# ----------------------------------------------------------------------
#  COMMAND: authority_client_address <cid> <addr> <port>
#
#  Invoked automatically whenever a client connects to the server.
#  Adds the client address/port to a list of all known clients.
#  Other clients searching for peers can ask for a list of all known
#  clients.
# ----------------------------------------------------------------------
proc authority_client_address {cid addr port} {
    global client2address
    set client2address($cid) $addr
}

# ----------------------------------------------------------------------
#  COMMAND: authority_client_protocol <cid> <protocol>
#
#  Invoked automatically whenever a client declares its protocol
#  to the server.  Clients speaking the "worker" protocol are
#  kept on a special list.
# ----------------------------------------------------------------------
proc authority_client_protocol {cid protocol} {
    global worker_options client2address
    switch -glob -- $protocol {
        *<-worker* {
            puts $cid [list protocol hubzero:worker<-authority/1]
            puts $cid "options [array get worker_options] ip $client2address($cid)"
        }
        *<-foreman* {
            puts $cid [list protocol hubzero:foreman<-authority/1]
        }
        DEF* {
            # do nothing
        }
        default {
            error "don't recognize protocol \"$protocol\""
        }
    }
}

vwait main-loop