#!/usr/bin/env python3
#
#  Copyright (c) 2023, The OpenThread Authors.
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from cli import verify
from cli import verify_within
import cli
import time

# -----------------------------------------------------------------------------------------------------------------------
# Test description:

# This test covers behavior of leader take over (an already attached device
# trying to form their own partition and taking over the leader role).
#

test_name = __file__[:-3] if __file__.endswith('.py') else __file__
print('-' * 120)
print('Starting \'{}\''.format(test_name))

# -----------------------------------------------------------------------------------------------------------------------
# Creating `cli.Nodes` instances

speedup = 25
cli.Node.set_time_speedup_factor(speedup)

node1 = cli.Node()
node2 = cli.Node()
node3 = cli.Node()
child2 = cli.Node()

# -----------------------------------------------------------------------------------------------------------------------
# Form topology

node1.form('lto')
node2.join(node1)
node3.join(node1)

child2.allowlist_node(node2)
child2.join(node2, cli.JOIN_TYPE_REED)

verify(node1.get_state() == 'leader')
verify(node2.get_state() == 'router')
verify(node3.get_state() == 'router')
verify(child2.get_state() == 'child')

# -----------------------------------------------------------------------------------------------------------------------
# Test Implementation

node1.set_router_selection_jitter(1)

n1_weight = int(node1.get_leader_weight())

node2.set_leader_weight(n1_weight)

#- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Make sure we get `NonCapable` if local leader weight same as current leader's weight

error = None
try:
    node2.cli('state leader')
except cli.CliError as e:
    error = e

verify(error.message == 'NotCapable')

#- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Update local leader weight and try to take over the leader role on `node2`.

node2.set_leader_weight(n1_weight + 1)

old_partition_id = int(node2.get_partition_id())

node2.cli('state leader')

new_partition_id = int(node2.get_partition_id())
verify(new_partition_id != old_partition_id)


def check_leader_switch():
    for node in [node1, node2, node3, child2]:
        verify(int(node.get_partition_id()) == new_partition_id)
    verify(node1.get_state() == 'router')
    verify(node2.get_state() == 'leader')
    verify(node3.get_state() == 'router')
    verify(child2.get_state() == 'child')


verify_within(check_leader_switch, 30)

# -----------------------------------------------------------------------------------------------------------------------
# Test finished

cli.Node.finalize_all_nodes()

print('\'{}\' passed.'.format(test_name))