# SPDX-License-Identifier: CC0-1.0

"""
Haketilo unit tests - IndexedDB access
"""

# This file is part of Haketilo
#
# Copyright (C) 2021, Wojtek Kosior <koszko@koszko.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the CC0 1.0 Universal License as published by
# the Creative Commons Corporation.
#
# This program 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
# CC0 1.0 Universal License for more details.

import pytest
import json
from hashlib import sha256
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import WebDriverException

from ..script_loader import load_script

indexeddb_js = lambda: load_script('common/indexeddb.js')
broker_js = lambda: load_script('background/broadcast_broker.js') + ';start();'

def sample_file(contents):
    return {
        'hash_key': f'sha256-{sha256(contents.encode()).digest().hex()}',
        'contents': contents
    }

sample_files = {
    'report.spdx':              sample_file('<!-- dummy report -->'),
    'LICENSES/somelicense.txt': sample_file('Permission is granted...'),
    'hello.js':                 sample_file('console.log("hello!");\n'),
    'bye.js':                   sample_file('console.log("bye!");\n'),
    'combined.js':              sample_file('console.log("hello!\\nbye!");\n'),
    'README.md':                sample_file('# Python Frobnicator\n...')
}

sample_files_by_hash = dict([[file['hash_key'], file['contents']]
                             for file in sample_files.values()])

# Sample resource definitions. They'd normally contain more fields but here we
# use simplified versions.

def make_sample_resource():
    return {
        'source_copyright': [
            file_ref('report.spdx'),
            file_ref('LICENSES/somelicense.txt')
        ],
        'type': 'resource',
        'identifier': 'helloapple',
        'scripts': [file_ref('hello.js'), file_ref('bye.js')]
    }

def make_sample_mapping():
    return {
        'source_copyright': [
            file_ref('report.spdx'),
            file_ref('README.md')
        ],
        'type': 'mapping',
        'identifier': 'helloapple'
    }

def file_ref(file_name):
    return {'file': file_name, 'hash_key': sample_files[file_name]['hash_key']}

@pytest.mark.get_page('https://gotmyowndoma.in')
def test_haketilodb_save_remove(execute_in_page):
    """
    indexeddb.js facilitates operating on Haketilo's internal database.
    Verify database operations work properly.
    """
    execute_in_page(indexeddb_js())
    # Mock some unwanted imports.
    execute_in_page(
        '''{
        initial_data = {};

        const broadcast_mock = {};
        const nop = () => {};
        for (const key in broadcast)
            broadcast_mock[key] = nop;
        broadcast = broadcast_mock;
        }''')

    # Start with no database.
    execute_in_page(
        '''
        async function delete_db() {
            if (db) {
                db.close();
                db = null;
            }
            let resolve, reject;
            const result = new Promise((...cbs) => [resolve, reject] = cbs);
            const request = indexedDB.deleteDatabase("haketilo");
            [request.onsuccess, request.onerror] = [resolve, reject];
            await result;
        }

        returnval(delete_db());
        '''
    )

    # Facilitate retrieving all IndexedDB contents.
    execute_in_page(
        '''
        async function get_database_contents()
        {
            const db = await get_db();

            const transaction = db.transaction(db.objectStoreNames);
            const store_names_reqs = [...db.objectStoreNames]
                .map(sn => [sn, transaction.objectStore(sn).getAll()])

            const promises = store_names_reqs
                .map(([_, req]) => wait_request(req));
            await Promise.all(promises);

            const result = {};
            store_names_reqs.forEach(([sn, req]) => result[sn] = req.result);
            return result;
        }
        ''')

    sample_item = make_sample_resource()
    sample_item['source_copyright'][0]['extra_prop'] = True

    database_contents = execute_in_page(
        '''{
        const promise = start_items_transaction(["resources"], arguments[1])
            .then(ctx => save_item(arguments[0], ctx).then(() => ctx))
            .then(finalize_items_transaction)
            .then(get_database_contents);
        returnval(promise);
        }''',
        sample_item, sample_files_by_hash)
    assert len(database_contents['files']) == 4
    assert all([sample_files_by_hash[file['hash_key']] == file['contents']
                for file in database_contents['files']])
    assert all([len(file) == 2 for file in database_contents['files']])

    assert len(database_contents['file_uses']) == 4
    assert all([uses['uses'] == 1 for uses in database_contents['file_uses']])
    assert set([uses['hash_key'] for uses in database_contents['file_uses']]) \
        == set([file['hash_key'] for file in database_contents['files']])

    assert database_contents['mappings'] == []
    assert database_contents['resources'] == [sample_item]

    # See if trying to add an item without providing all its files ends in an
    # exception and aborts the transaction as it should.
    sample_item['scripts'].append(file_ref('combined.js'))
    incomplete_files = {**sample_files_by_hash}
    incomplete_files.pop(sample_files['combined.js']['hash_key'])
    result = execute_in_page(
        '''{
        const promise = (async () => {
            const context =
                await start_items_transaction(["resources"], arguments[1]);
            try {
                await save_item(arguments[0], context);
                await finalize_items_transaction(context);
                return {};
            } catch(e) {
                var exception = e;
            }

            return {exception, db_contents: await get_database_contents()};
        })();
        returnval(promise);
        }''',
        sample_item, incomplete_files)

    assert result
    assert 'file not present' in result['exception']
    for key, val in database_contents.items():
        keyfun = lambda item: item.get('hash_key') or item['identifier']
        assert sorted(result['db_contents'][key], key=keyfun) \
            == sorted(val,                        key=keyfun)

    # See if adding another item that partially uses first's files works OK.
    sample_item = make_sample_mapping()
    database_contents = execute_in_page(
        '''{
        const promise = start_items_transaction(["mappings"], arguments[1])
            .then(ctx => save_item(arguments[0], ctx).then(() => ctx))
            .then(finalize_items_transaction)
            .then(get_database_contents);
        returnval(promise);
        }''',
        sample_item, sample_files_by_hash)

    names = ['README.md', 'report.spdx', 'LICENSES/somelicense.txt', 'hello.js',
             'bye.js']
    sample_files_list = [sample_files[name] for name in names]
    uses_list = [1, 2, 1, 1, 1]

    uses = dict([(uses['hash_key'], uses['uses'])
                 for uses in database_contents['file_uses']])
    assert uses  == dict([(file['hash_key'], nr)
                          for file, nr in zip(sample_files_list, uses_list)])

    files = dict([(file['hash_key'], file['contents'])
                  for file in database_contents['files']])
    assert files == dict([(file['hash_key'], file['contents'])
                          for file in sample_files_list])

    del database_contents['resources'][0]['source_copyright'][0]['extra_prop']
    assert database_contents['resources'] == [make_sample_resource()]
    assert database_contents['mappings']  == [sample_item]

    # Try removing the items to get an empty database again.
    results = [None, None]
    for i, item_type in enumerate(['resource', 'mapping']):
         results[i] = execute_in_page(
            f'''{{
            const remover = remove_{item_type};
            const promise =
                start_items_transaction(["{item_type}s"], {{}})
                .then(ctx => remover('helloapple', ctx).then(() => ctx))
                .then(finalize_items_transaction)
                .then(get_database_contents);
            returnval(promise);
            }}''')

    names = ['README.md', 'report.spdx']
    sample_files_list = [sample_files[name] for name in names]
    uses_list = [1, 1]

    uses = dict([(uses['hash_key'], uses['uses'])
                 for uses in results[0]['file_uses']])
    assert uses  == dict([(file['hash_key'], 1) for file in sample_files_list])

    files = dict([(file['hash_key'], file['contents'])
                  for file in results[0]['files']])
    assert files == dict([(file['hash_key'], file['contents'])
                          for file in sample_files_list])

    assert results[0]['resources'] == []
    assert results[0]['mappings'] == [sample_item]

    assert results[1] == dict([(key, []) for key in  results[0].keys()])

    # Try initializing an empty database with sample initial data object.
    sample_resource = make_sample_resource()
    sample_mapping = make_sample_mapping()
    initial_data = {
        'resources': {
            'helloapple': {
                '1.12':   sample_resource,
                '0.9':    'something_that_should_get_ignored',
                '1':      'something_that_should_get_ignored',
                '1.1':    'something_that_should_get_ignored',
                '1.11.1': 'something_that_should_get_ignored',
            }
        },
        'mappings': {
            'helloapple': {
                '0.1.1': sample_mapping
            }
        },
        'files': sample_files_by_hash
    }
    database_contents = execute_in_page(
        '''
        initial_data = arguments[0];
        returnval(delete_db().then(() => get_database_contents()));
        ''',
        initial_data)
    assert database_contents['resources'] == [sample_resource]
    assert database_contents['mappings']  == [sample_mapping]

test_page_html = '''
<!DOCTYPE html>
<script src="/testpage.js"></script>
<h2>resources</h2>
<ul id="resources"></ul>
<h2>mappings</h2>
<ul id="mappings"></ul>
'''

@pytest.mark.ext_data({
    'background_script': broker_js,
    'test_page':         test_page_html,
    'extra_files': {
        'testpage.js':   indexeddb_js
    }
})
@pytest.mark.usefixtures('webextension')
def test_haketilodb_track(driver, execute_in_page, wait_elem_text):
    """
    Verify IndexedDB object change notifications are correctly broadcasted
    through extension's background script and allow for object store contents
    to be tracked in any execution context.
    """
    # Let's open the same extension's test page in a second window. Window 0
    # will be used to make changed to IndexedDB and window 1 to "track" those
    # changes.
    driver.execute_script('window.open(window.location.href, "_blank");')
    windows = [*driver.window_handles]
    assert len(windows) == 2

    # Mock initial_data.
    sample_resource = make_sample_resource()
    sample_mapping = make_sample_mapping()
    initial_data = {
        'resources': {
            'helloapple': {
                '1.0': sample_resource
            }
        },
        'mappings': {
            'helloapple': {
                '0.1.1': sample_mapping
            }
        },
        'files': sample_files_by_hash
    }
    for window in reversed(windows):
        driver.switch_to.window(window)
        execute_in_page('initial_data = arguments[0];', initial_data)

    # See if track_*() functions properly return the already-existing items.
    execute_in_page(
        '''
        function update_item(store_name, change)
        {
            console.log('update', ...arguments);
            const elem_id = `${store_name}_${change.identifier}`;
            let elem = document.getElementById(elem_id);
            elem = elem || document.createElement("li");
            elem.id = elem_id;
            elem.innerText = JSON.stringify(change.new_val);
            document.getElementById(store_name).append(elem);
            if (change.new_val === undefined)
                elem.remove();
        }

        let resource_tracking, resource_items, mapping_tracking, mapping_items;

        async function start_tracking()
        {
            const update_resource = change => update_item("resources", change);
            const update_mapping  = change => update_item("mappings",  change);

            [resource_tracking, resource_items] =
                await track_resources(update_resource);
            [mapping_tracking, mapping_items] =
                await track_mappings(update_mapping);

            for (const item of resource_items)
                update_resource({identifier: item.identifier, new_val: item});
            for (const item of mapping_items)
                update_mapping({identifier: item.identifier, new_val: item});
        }

        returnval(start_tracking());
        ''')

    item_counts = driver.execute_script(
        '''
        const childcount = id => document.getElementById(id).childElementCount;
        return ["resources", "mappings"].map(childcount);
        ''')
    assert item_counts == [1, 1]
    resource_json = driver.find_element_by_id('resources_helloapple').text
    mapping_json =  driver.find_element_by_id('mappings_helloapple').text
    assert json.loads(resource_json) == sample_resource
    assert json.loads(mapping_json)  == sample_mapping

    # See if item additions get tracked properly.
    driver.switch_to.window(windows[1])
    sample_resource2 = make_sample_resource()
    sample_resource2['identifier'] = 'helloapple-copy'
    sample_mapping2 = make_sample_mapping()
    sample_mapping2['identifier'] = 'helloapple-copy'
    sample_data = {
        'resources': {
            'helloapple-copy': {
                '1.0': sample_resource2
            }
        },
        'mappings': {
            'helloapple-copy': {
                '0.1.1': sample_mapping2
            }
        },
        'files': sample_files_by_hash
    }
    execute_in_page('returnval(save_items(arguments[0]));', sample_data)

    driver.switch_to.window(windows[0])
    driver.implicitly_wait(10)
    resource_json = driver.find_element_by_id('resources_helloapple-copy').text
    mapping_json =  driver.find_element_by_id('mappings_helloapple-copy').text
    driver.implicitly_wait(0)
    assert json.loads(resource_json) == sample_resource2
    assert json.loads(mapping_json)  == sample_mapping2

    # See if item deletions get tracked properly.
    driver.switch_to.window(windows[1])
    execute_in_page(
        '''{
        async function remove_items()
        {
            const store_names = ["resources", "mappings"];
            const ctx = await start_items_transaction(store_names, {});
            await remove_resource("helloapple", ctx);
            await remove_mapping("helloapple-copy", ctx);
            await finalize_items_transaction(ctx);
        }
        returnval(remove_items());
        }''')

    removed_ids = ['mappings_helloapple-copy', 'resources_helloapple']
    def condition_items_absent(driver):
        for id in removed_ids:
            try:
                driver.find_element_by_id(id)
                return False
            except WebDriverException:
                pass
        return True

    driver.switch_to.window(windows[0])
    WebDriverWait(driver, 10).until(condition_items_absent)