// Copyright (C) Moondance Labs Ltd.
// This file is part of Tanssi.

// Tanssi is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Tanssi is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Tanssi.  If not, see <http://www.gnu.org/licenses/>

use {
    crate::{
        mock::{
            last_event, new_test_ext, run_to_block, run_to_session, ExternalValidators, HookCall,
            Mock, RootAccount, RuntimeEvent, RuntimeOrigin, Session, System, Test,
        },
        traits::{ExternalIndexProvider, ValidatorProvider},
        Error,
    },
    frame_support::{assert_noop, assert_ok},
    sp_runtime::traits::BadOrigin,
};

#[test]
fn basic_setup_works() {
    new_test_ext().execute_with(|| {
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);
    });
}

#[test]
fn add_whitelisted_works() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);
        let new = 3;

        // function runs
        assert_ok!(ExternalValidators::add_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            new
        ));

        System::assert_last_event(RuntimeEvent::ExternalValidators(
            crate::Event::WhitelistedValidatorAdded { account_id: new },
        ));

        // same element cannot be added more than once
        assert_noop!(
            ExternalValidators::add_whitelisted(RuntimeOrigin::signed(RootAccount::get()), new),
            Error::<Test>::AlreadyWhitelisted
        );

        // new element is now part of the invulnerables list
        assert!(ExternalValidators::whitelisted_validators()
            .to_vec()
            .contains(&new));

        // cannot add with non-root
        assert_noop!(
            ExternalValidators::add_whitelisted(RuntimeOrigin::signed(1), new),
            BadOrigin
        );
    });
}

#[test]
fn add_whitelisted_does_not_work_if_not_registered() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);
        let new = 42;

        assert_noop!(
            ExternalValidators::add_whitelisted(RuntimeOrigin::signed(RootAccount::get()), new),
            Error::<Test>::NoKeysRegistered
        );
    });
}

#[test]
fn validator_limit_works() {
    new_test_ext().execute_with(|| {
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);

        // MaxExternalValidators: u32 = 20
        for ii in 3..=21 {
            if ii < 21 {
                assert_ok!(ExternalValidators::add_whitelisted(
                    RuntimeOrigin::signed(RootAccount::get()),
                    ii
                ));
            } else {
                assert_noop!(
                    ExternalValidators::add_whitelisted(
                        RuntimeOrigin::signed(RootAccount::get()),
                        ii
                    ),
                    Error::<Test>::TooManyWhitelisted
                );
            }
        }
        let expected: Vec<u64> = (1..=20).collect();
        assert_eq!(ExternalValidators::whitelisted_validators(), expected);
    });
}

#[test]
fn remove_whitelisted_works() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);

        assert_ok!(ExternalValidators::add_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            4
        ));
        assert_ok!(ExternalValidators::add_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            3
        ));

        assert_eq!(
            ExternalValidators::whitelisted_validators(),
            vec![1, 2, 4, 3]
        );

        assert_ok!(ExternalValidators::remove_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            2
        ));

        System::assert_last_event(RuntimeEvent::ExternalValidators(
            crate::Event::WhitelistedValidatorRemoved { account_id: 2 },
        ));
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 4, 3]);

        // cannot remove invulnerable not in the list
        assert_noop!(
            ExternalValidators::remove_whitelisted(RuntimeOrigin::signed(RootAccount::get()), 2),
            Error::<Test>::NotWhitelisted
        );

        // cannot remove without privilege
        assert_noop!(
            ExternalValidators::remove_whitelisted(RuntimeOrigin::signed(1), 3),
            BadOrigin
        );
    });
}

#[test]
fn whitelisted_and_external_order() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![50, 51],
            1
        ));

        run_to_session(6);
        let validators = Session::validators();
        let external_index = ExternalValidators::get_external_index();
        assert_eq!(validators, vec![1, 2, 50, 51]);
        assert_eq!(external_index, 1);
    });
}

#[test]
fn validator_provider_returns_all_validators() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![50, 51],
            1
        ));

        run_to_session(6);
        let validators_new_session = Session::validators();
        let validators_provider = <ExternalValidators as ValidatorProvider<u64>>::validators();
        assert_eq!(validators_new_session, validators_provider);
    });
}

#[test]
fn can_skip_external_validators() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![50, 51],
            1
        ));
        assert_ok!(ExternalValidators::skip_external_validators(
            RuntimeOrigin::signed(RootAccount::get()),
            true
        ));

        run_to_session(6);
        let validators = Session::validators();
        assert_eq!(validators, vec![1, 2]);
    });
}

#[test]
fn duplicate_validators_are_deduplicated() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![1, 2]);
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![2],
            1
        ));

        run_to_session(6);
        let validators = Session::validators();
        assert_eq!(validators, vec![1, 2]);
    });
}

#[test]
fn duplicate_validator_order_is_preserved() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        // Whitelisted validators have priority, so their ordering should be respected
        // Need to manually remove and add each whitelisted because there is no "set_whitelisted"
        assert_ok!(ExternalValidators::remove_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            1
        ));
        assert_ok!(ExternalValidators::remove_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            2
        ));
        assert_ok!(ExternalValidators::add_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            3
        ));
        assert_ok!(ExternalValidators::add_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            1
        ));
        assert_ok!(ExternalValidators::add_whitelisted(
            RuntimeOrigin::signed(RootAccount::get()),
            2
        ));
        assert_eq!(ExternalValidators::whitelisted_validators(), vec![3, 1, 2]);
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![3, 2, 1, 4],
            1
        ));

        run_to_session(6);
        let validators = Session::validators();
        assert_eq!(validators, vec![3, 1, 2, 4]);
    });
}

#[test]
fn external_index_gets_set_correctly() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![2],
            1
        ));
        let external_index = ExternalValidators::get_external_index();
        assert_eq!(external_index, 0);
        run_to_session(6);

        let external_index = ExternalValidators::get_external_index();
        assert_eq!(external_index, 1);
    });
}

#[test]
fn setting_external_validators_emits_event() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![2, 3],
            1
        ));
        let event = RuntimeEvent::ExternalValidators(crate::Event::ExternalValidatorsSet {
            validators: vec![2, 3],
            external_index: 1,
        });
        assert_eq!(last_event(), event);
    });
}

#[test]
fn setting_external_validators_with_more_than_max_external_validators_emits_correct_event() {
    new_test_ext().execute_with(|| {
        run_to_block(1);
        let max_external_validators = 20u64;
        // Current max external validators is 20 so if we try to set 25 validators
        // We expect only the first 20 to be set as external validators
        assert_ok!(ExternalValidators::set_external_validators_inner(
            (1..(max_external_validators + 5)).collect(),
            1
        ));
        let event = RuntimeEvent::ExternalValidators(crate::Event::ExternalValidatorsSet {
            validators: (1..(max_external_validators + 1)).collect(),
            external_index: 1,
        });
        assert_eq!(last_event(), event);
    });
}

#[test]
fn era_hooks() {
    new_test_ext().execute_with(|| {
        run_to_session(14);

        let expected_calls = vec![
            HookCall::OnEraStart {
                era: 0,
                session: 0,
                external_index: 0,
            },
            HookCall::OnEraEnd { era: 0 },
            HookCall::OnEraStart {
                era: 1,
                session: 6,
                external_index: 0,
            },
            HookCall::OnEraEnd { era: 1 },
            HookCall::OnEraStart {
                era: 2,
                session: 12,
                external_index: 0,
            },
        ];

        assert_eq!(Mock::mock().called_hooks, expected_calls);
    });
}

#[test]
fn era_hooks_with_external_index() {
    new_test_ext().execute_with(|| {
        let first_external_index = 1000;
        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![50, 51],
            first_external_index
        ));

        run_to_session(8);

        let second_external_index = 2000;

        assert_ok!(ExternalValidators::set_external_validators_inner(
            vec![50, 51],
            second_external_index
        ));

        run_to_session(14);

        let expected_calls = vec![
            HookCall::OnEraStart {
                era: 0,
                session: 0,
                external_index: 0,
            },
            HookCall::OnEraEnd { era: 0 },
            HookCall::OnEraStart {
                era: 1,
                session: 6,
                external_index: first_external_index,
            },
            HookCall::OnEraEnd { era: 1 },
            HookCall::OnEraStart {
                era: 2,
                session: 12,
                external_index: second_external_index,
            },
        ];

        assert_eq!(Mock::mock().called_hooks, expected_calls);
    });
}