import datetime
import logging

import connection, utils
import consts
import queries

PR_NAME = 'KDH-308_nr_data_export'

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)


def main():
    ts = datetime.datetime.now()
    generate_db_pr()
    print(f"Process took {(datetime.datetime.now() - ts).total_seconds()}")


def generate_db_pr():
    dump_queries = generate_dump_queries()
    changesets = []
    for i, query in enumerate(dump_queries, start=1):
        logger.info(f"Generating changeset {i}")
        changesets.append(consts.DB_CHANGESET_TEMPLATE.format(id=PR_NAME, i=i, query=query))
    db_pr_content = consts.DB_PR_TEMPLATE.format(changesets=''.join(changesets))
    with open(f'{PR_NAME}.xml', 'w') as f:
        f.write(db_pr_content)
    logger.info(f"PR file {PR_NAME}.xml generated")


def generate_dump_queries():
    result = []
    for labels in consts.LABELS:
        logger.info(f"Generating dump query for {labels}")
        result.append(_compose_label_dump_query(labels))
    for start_label, relationship, end_label in consts.RELATIONS:
        logger.info(f"Generating dump query for {start_label} {relationship} {end_label}")
        result.append(_compose_relationship_dump_query(start_label, relationship, end_label))
    return result


def dump_node_data(labels):
    ts = datetime.datetime.now()
    query = _compose_label_dump_query(labels)
    with connection.driver.session() as s_source:
        s_source.run(query)
    te = datetime.datetime.now()
    print(f"Dumping {labels} data took {(te - ts).total_seconds()}")


def dump_relationship_data(start_label, relationship, end_label):
    query = _compose_relationship_dump_query(start_label, relationship, end_label)
    with connection.driver.session() as s_source:
        s_source.run(query)


def _compose_relationship_dump_query(start_label, relationship, end_label):
    filename = utils.generate_relationship_json_filename(start_label, relationship, end_label)
    slabel = f':{start_label}'
    relation = f':{relationship}'
    elabel = f':{end_label}'
    properties = _get_relation_properties(slabel, relation, elabel)
    data_query = _compose_relation_data_query(slabel, relation, elabel, properties)
    return queries.DUMP_JSON.format(query=data_query, filename=filename)


def _get_relation_properties(start_label, relationship, end_label):
    with connection.driver.session() as s_source:
        cypher = queries.RELATION_UNIQUE_KEYS.format(
            start_label=start_label, relationship=relationship, end_label=end_label)
        properties_result = s_source.run(cypher)
        properties = properties_result.value()[0]
        return properties


def _compose_relation_data_query(start_label, relationship, end_label, properties):
    """Compose a query to dump the properties of a node."""
    properties_str = 'n.id as startId, k.id as endId, ' + ', '.join([f'r.{p} as {p}' for p in properties])
    cypher = queries.RELATION_DATA.format(
        start_label=start_label, relationship=relationship, end_label=end_label, properties=properties_str)
    return cypher


### Label helpers

# def _get_node_properties(node_labels, exclude_labels):
#     """Find all property names for the given node labels."""
#     with connection.driver.session() as s_source:
#         cypher = queries.LABEL_UNIQUE_KEYS.format(labels=node_labels, exclude_labels=exclude_labels)
#         properties_result = s_source.run(cypher)
#         properties = properties_result.value()[0]
#         return properties


def _compose_node_data_query(node_labels, exclude_node_labels, properties):
    """Compose a query to dump the properties of a node."""
    properties_str = ', '.join([f'n.{p} as {p}' for p in properties])
    cypher = queries.NODE_DATA.format(labels=node_labels, exclude_labels=exclude_node_labels, properties=properties_str)
    return cypher


def _compose_label_dump_query(labels):
    query_labels = labels['labels']
    exclude_labels = labels.get('exclude', [])
    filename = utils.generate_labels_json_filename(query_labels)
    node_labels = ':' + ':'.join(query_labels)
    if exclude_labels:
        exclude_node_labels = '\n                WHERE ' + ' and '.join([f'NOT n:{label}' for label in exclude_labels])
    else:
        exclude_node_labels = ''
    properties = utils.get_node_properties(node_labels, exclude_node_labels)
    node_data_query = _compose_node_data_query(node_labels, exclude_node_labels, properties)
    return queries.DUMP_JSON.format(query=node_data_query, filename=filename)


if __name__ == '__main__':
    main()