/*
 * Copyright (C) 2015 ScyllaDB
 */

/*
 * This file is part of Scylla.
 *
 * Scylla is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Scylla 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 Scylla.  If not, see <http://www.gnu.org/licenses/>.
 */


#include <boost/test/unit_test.hpp>
#include <boost/range/irange.hpp>

#include "tests/test-utils.hh"
#include "tests/mutation_assertions.hh"
#include "tests/mutation_reader_assertions.hh"

#include "mutation_reader.hh"
#include "core/do_with.hh"
#include "core/thread.hh"
#include "schema_builder.hh"

#include "disk-error-handler.hh"

thread_local disk_error_signal_type commit_error;
thread_local disk_error_signal_type general_disk_error;

static schema_ptr make_schema() {
    return schema_builder("ks", "cf")
        .with_column("pk", bytes_type, column_kind::partition_key)
        .with_column("v", bytes_type, column_kind::regular_column)
        .build();
}

SEASTAR_TEST_CASE(test_combining_two_readers_with_the_same_row) {
    return seastar::async([] {
        auto s = make_schema();

        mutation m1(partition_key::from_single_value(*s, "key1"), s);
        m1.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v1")), 1);

        mutation m2(partition_key::from_single_value(*s, "key1"), s);
        m2.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v2")), 2);

        assert_that(make_combined_reader(make_reader_returning(m1), make_reader_returning(m2)))
            .produces(m2)
            .produces_end_of_stream();
    });
}

SEASTAR_TEST_CASE(test_combining_two_non_overlapping_readers) {
    return seastar::async([] {
        auto s = make_schema();

        mutation m1(partition_key::from_single_value(*s, "keyB"), s);
        m1.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v1")), 1);

        mutation m2(partition_key::from_single_value(*s, "keyA"), s);
        m2.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v2")), 2);

        auto cr = make_combined_reader(make_reader_returning(m1), make_reader_returning(m2));
        assert_that(std::move(cr))
            .produces(m2)
            .produces(m1)
            .produces_end_of_stream();
    });
}

SEASTAR_TEST_CASE(test_combining_two_partially_overlapping_readers) {
    return seastar::async([] {
        auto s = make_schema();

        mutation m1(partition_key::from_single_value(*s, "keyA"), s);
        m1.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v1")), 1);

        mutation m2(partition_key::from_single_value(*s, "keyB"), s);
        m2.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v2")), 1);

        mutation m3(partition_key::from_single_value(*s, "keyC"), s);
        m3.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v3")), 1);

        assert_that(make_combined_reader(make_reader_returning_many({m1, m2}), make_reader_returning_many({m2, m3})))
            .produces(m1)
            .produces(m2)
            .produces(m3)
            .produces_end_of_stream();
    });
}

SEASTAR_TEST_CASE(test_combining_one_reader_with_many_partitions) {
    return seastar::async([] {
        auto s = make_schema();

        mutation m1(partition_key::from_single_value(*s, "keyA"), s);
        m1.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v1")), 1);

        mutation m2(partition_key::from_single_value(*s, "keyB"), s);
        m2.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v2")), 1);

        mutation m3(partition_key::from_single_value(*s, "keyC"), s);
        m3.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v3")), 1);

        std::vector<mutation_reader> v;
        v.push_back(make_reader_returning_many({m1, m2, m3}));
        assert_that(make_combined_reader(std::move(v)))
            .produces(m1)
            .produces(m2)
            .produces(m3)
            .produces_end_of_stream();
    });
}

static mutation make_mutation_with_key(schema_ptr s, dht::decorated_key dk) {
    mutation m(std::move(dk), s);
    m.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v1")), 1);
    return m;
}

static mutation make_mutation_with_key(schema_ptr s, const char* key) {
    return make_mutation_with_key(s, dht::global_partitioner().decorate_key(*s, partition_key::from_single_value(*s, bytes(key))));
}

SEASTAR_TEST_CASE(test_filtering) {
    return seastar::async([] {
        auto s = make_schema();

        auto m1 = make_mutation_with_key(s, "key1");
        auto m2 = make_mutation_with_key(s, "key2");
        auto m3 = make_mutation_with_key(s, "key3");
        auto m4 = make_mutation_with_key(s, "key4");

        // All pass
        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
                 [] (const streamed_mutation& m) { return true; }))
            .produces(m1)
            .produces(m2)
            .produces(m3)
            .produces(m4)
            .produces_end_of_stream();

        // None pass
        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
                 [] (const streamed_mutation& m) { return false; }))
            .produces_end_of_stream();

        // Trim front
        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
                [&] (const streamed_mutation& m) { return !m.key().equal(*s, m1.key()); }))
            .produces(m2)
            .produces(m3)
            .produces(m4)
            .produces_end_of_stream();

        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
            [&] (const streamed_mutation& m) { return !m.key().equal(*s, m1.key()) && !m.key().equal(*s, m2.key()); }))
            .produces(m3)
            .produces(m4)
            .produces_end_of_stream();

        // Trim back
        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
                 [&] (const streamed_mutation& m) { return !m.key().equal(*s, m4.key()); }))
            .produces(m1)
            .produces(m2)
            .produces(m3)
            .produces_end_of_stream();

        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
                 [&] (const streamed_mutation& m) { return !m.key().equal(*s, m4.key()) && !m.key().equal(*s, m3.key()); }))
            .produces(m1)
            .produces(m2)
            .produces_end_of_stream();

        // Trim middle
        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
                 [&] (const streamed_mutation& m) { return !m.key().equal(*s, m3.key()); }))
            .produces(m1)
            .produces(m2)
            .produces(m4)
            .produces_end_of_stream();

        assert_that(make_filtering_reader(make_reader_returning_many({m1, m2, m3, m4}),
                 [&] (const streamed_mutation& m) { return !m.key().equal(*s, m2.key()) && !m.key().equal(*s, m3.key()); }))
            .produces(m1)
            .produces(m4)
            .produces_end_of_stream();
    });
}

SEASTAR_TEST_CASE(test_combining_two_readers_with_one_reader_empty) {
    return seastar::async([] {
        auto s = make_schema();
        mutation m1(partition_key::from_single_value(*s, "key1"), s);
        m1.set_clustered_cell(clustering_key::make_empty(), "v", data_value(bytes("v1")), 1);

        assert_that(make_combined_reader(make_reader_returning(m1), make_empty_reader()))
            .produces(m1)
            .produces_end_of_stream();
    });
}

SEASTAR_TEST_CASE(test_combining_two_empty_readers) {
    return seastar::async([] {
        assert_that(make_combined_reader(make_empty_reader(), make_empty_reader()))
            .produces_end_of_stream();
    });
}

SEASTAR_TEST_CASE(test_combining_one_empty_reader) {
    return seastar::async([] {
        std::vector<mutation_reader> v;
        v.push_back(make_empty_reader());
        assert_that(make_combined_reader(std::move(v)))
            .produces_end_of_stream();
    });
}

std::vector<dht::decorated_key> generate_keys(schema_ptr s, int count) {
    auto keys = boost::copy_range<std::vector<dht::decorated_key>>(
        boost::irange(0, count) | boost::adaptors::transformed([s] (int key) {
            auto pk = partition_key::from_single_value(*s, int32_type->decompose(data_value(key)));
            return dht::global_partitioner().decorate_key(*s, std::move(pk));
        }));
    return std::move(boost::range::sort(keys, dht::decorated_key::less_comparator(s)));
}

std::vector<dht::ring_position> to_ring_positions(const std::vector<dht::decorated_key>& keys) {
    return boost::copy_range<std::vector<dht::ring_position>>(keys | boost::adaptors::transformed([] (const dht::decorated_key& key) {
        return dht::ring_position(key);
    }));
}

SEASTAR_TEST_CASE(test_fast_forwarding_combining_reader) {
    return seastar::async([] {
        auto s = make_schema();

        auto keys = generate_keys(s, 7);
        auto ring = to_ring_positions(keys);

        std::vector<std::vector<mutation>> mutations {
            {
                make_mutation_with_key(s, keys[0]),
                make_mutation_with_key(s, keys[1]),
                make_mutation_with_key(s, keys[2]),
            },
            {
                make_mutation_with_key(s, keys[2]),
                make_mutation_with_key(s, keys[3]),
                make_mutation_with_key(s, keys[4]),
            },
            {
                make_mutation_with_key(s, keys[1]),
                make_mutation_with_key(s, keys[3]),
                make_mutation_with_key(s, keys[5]),
            },
            {
                make_mutation_with_key(s, keys[0]),
                make_mutation_with_key(s, keys[5]),
                make_mutation_with_key(s, keys[6]),
            },
        };

        auto make_reader = [&] (const dht::partition_range& pr) {
            std::vector<mutation_reader> readers;
            boost::range::transform(mutations, std::back_inserter(readers), [&pr] (auto& ms) {
                return make_reader_returning_many(ms, pr);
            });
            return make_combined_reader(std::move(readers));
        };

        auto pr = dht::partition_range::make_open_ended_both_sides();
        assert_that(make_reader(pr))
            .produces(keys[0])
            .produces(keys[1])
            .produces(keys[2])
            .produces(keys[3])
            .produces(keys[4])
            .produces(keys[5])
            .produces(keys[6])
            .produces_end_of_stream();

        pr = dht::partition_range::make(ring[0], ring[0]);
            assert_that(make_reader(pr))
                    .produces(keys[0])
                    .produces_end_of_stream()
                    .fast_forward_to(dht::partition_range::make(ring[1], ring[1]))
                    .produces(keys[1])
                    .produces_end_of_stream()
                    .fast_forward_to(dht::partition_range::make(ring[3], ring[4]))
                    .produces(keys[3])
            .fast_forward_to(dht::partition_range::make({ ring[4], false }, ring[5]))
                    .produces(keys[5])
                    .produces_end_of_stream()
            .fast_forward_to(dht::partition_range::make_starting_with(ring[6]))
                    .produces(keys[6])
                    .produces_end_of_stream();
    });
}

SEASTAR_TEST_CASE(test_multi_range_reader) {
        return seastar::async([] {
            auto s = make_schema();

            auto keys = generate_keys(s, 10);
            auto ring = to_ring_positions(keys);

            auto ms = boost::copy_range<std::vector<mutation>>(keys | boost::adaptors::transformed([s] (auto& key) {
                return make_mutation_with_key(s, key);
            }));

            auto source = mutation_source([&] (schema_ptr, const dht::partition_range& range) {
                return make_reader_returning_many(std::move(ms), range);
            });

            auto ranges = dht::partition_range_vector {
                    dht::partition_range::make(ring[1], ring[2]),
                    dht::partition_range::make_singular(ring[4]),
                    dht::partition_range::make(ring[6], ring[8]),
            };
            auto fft_range = dht::partition_range::make_starting_with(ring[9]);

            assert_that(make_multi_range_reader(s, std::move(source), ranges, query::full_slice))
                    .produces(keys[1])
                    .produces(keys[2])
                    .produces(keys[4])
                    .produces(keys[6])
                    .fast_forward_to(fft_range)
                    .produces(keys[9])
                    .produces_end_of_stream();
        });
}