import time

from sanic import Blueprint, response

from .decorators import auth_route
from .streaming import OP
from ..snowflake import get_snowflake


bp = Blueprint(__name__)

# since sqlite uses bigints, we make sure
# we get the same type being sent over.
# (yes, I know sqlite can accept floats
#  in a bigint column, but having a float
#  would cause API inconsistency).
_time = lambda: int(time.time())


def fetch_incident(conn, incident_id: dict) -> tuple:
    """Fetch a single incident's row."""
    cur = conn.cursor()

    cur.execute("""
    SELECT id, incident_type, title, content, ongoing,
        start_timestamp, end_timestamp
    FROM incidents
    WHERE id = ?
    """, (incident_id,))

    return cur.fetchone()


def fetch_stages(conn, incident_id: int) -> list:
    """Fetch all the stages for an incident"""
    cur = conn.cursor()

    cur.execute("""
    SELECT title, content, timestamp
    FROM incident_stages
    WHERE parent_id = ?
    ORDER BY timestamp ASC
    """, (incident_id,))

    stage_rows = cur.fetchall()

    def stage_obj(stage_row) -> dict:
        """give a stage dict, given the stage row."""
        return {
            'title': stage_row[0],
            'content': stage_row[1],
            'created_at': stage_row[2],
        }

    return list(map(stage_obj, stage_rows))


def publish_update(manager, incident_id: int):
    """Publish an update to an incident.

    This makes sure the data being published is the latest
    by requering the database.
    """
    full = fetch_dict(manager.conn, incident_id)
    manager.publish_incident(OP.INC_UPDATE, full)


def incident_dict(conn, row) -> dict:
    """make an incident dict, given incident row."""
    return {
        'id': str(row[0]),
        'type': row[1],
        'title': row[2],
        'content': row[3],
        'ongoing': row[4],

        'start_date': row[5],
        'end_date': row[6],

        'stages': fetch_stages(conn, row[0])
    }


def fetch_dict(conn, incident_id) -> dict:
    """Fetch an incident and return a dictionary."""
    row = fetch_incident(conn, incident_id)
    return incident_dict(conn, row)


@bp.get('/api/incidents/current')
async def get_current_incident(request):
    """Get the current incident, if any."""
    manager = request.app.manager
    cur = manager.conn.cursor()

    cur.execute("""
    SELECT id, incident_type, title, content, ongoing,
        start_timestamp, end_timestamp
    FROM incidents
    ORDER BY id ASC
    LIMIT 1
    """)

    rows = cur.fetchall()

    try:
        row = next(iter(rows))
        drow = incident_dict(manager.conn, row)
    except StopIteration:
        row = None
        drow = {}

    return response.json({
        'all_good': not drow.get('ongoing'),
        'current_incident': None if drow == {} else drow
    })


@bp.get('/api/incidents/<page:int>')
async def get_incidents(request, page: int):
    """Get a list of incidents."""
    manager = request.app.manager
    cur = manager.conn.cursor()

    cur.execute(f"""
    SELECT id, incident_type, title, content, ongoing,
        start_timestamp, end_timestamp
    FROM incidents
    ORDER BY id DESC

    LIMIT 10
    OFFSET ({page} * 10)
    """)

    rows = cur.fetchall()

    res = []

    for row in rows:
        res.append(incident_dict(manager.conn, row))

    return response.json(res)


@bp.put('/api/incidents')
@auth_route
async def create_incident(request):
    """Create a new incident and put it as ongoing by default."""
    incident = request.json
    manager = request.app.manager

    incident_id = get_snowflake()
    start_timestamp = _time()

    manager.conn.execute("""
    INSERT INTO incidents (id, incident_type, title, content,
        ongoing, start_timestamp, end_timestamp)
    VALUES (?, ?, ?, ?, true, ?, NULL)
    """, (
        incident_id,
        incident['type'],
        incident['title'],
        incident['content'],
        start_timestamp,
    ))
    manager.conn.commit()

    # refetch so we know we have the good stuff
    incident = fetch_dict(manager.conn, incident_id)
    manager.publish_incident(OP.INCIDENT_NEW, incident)
    return response.json(incident)


@bp.patch('/api/incidents/<incident_id:int>')
@auth_route
async def patch_incident(request, incident_id):
    """Patch an existing incident."""
    incident = request.json
    manager = request.app.manager

    if 'end_timestamp' not in incident and not incident['ongoing']:
        incident['end_timestamp'] = _time()

    orig = fetch_dict(manager.conn, incident_id)

    def _get(field):
        return incident.get(field, orig[field])

    manager.conn.execute("""
    UPDATE incidents
    SET
        incident_type = ?,
        title = ?,
        content = ?,
        ongoing = ?,
        start_timestamp = ?,
        end_timestamp = ?
    WHERE
        id = ?
    """, (
        _get('type'),
        _get('title'),
        _get('content'),
        _get('ongoing'),
        _get('start_date'),
        _get('end_date'),
        incident_id,
    ))

    manager.conn.commit()

    if incident['ongoing']:
        publish_update(manager, incident_id)
    else:
        manager.publish_incident(OP.INCIDENT_CLOSE, {**incident, **{
            'id': str(incident_id)
        }})

    return response.text('', status=204)


@bp.post('/api/incidents/<incident_id:int>/stages')
@auth_route
async def new_stage(request, incident_id):
    """Create a new stage in an incident."""
    stage = request.json
    manager = request.app.manager

    timestamp = _time()

    manager.conn.execute("""
    INSERT INTO incident_stages (parent_id, timestamp, title, content)
    VALUES (?, ?, ?, ?)
    """, (incident_id, timestamp, stage['title'], stage['content']))
    manager.conn.commit()

    publish_update(manager, incident_id)

    return response.json({**{
        'parent_id': str(incident_id),
        'created_at': timestamp,
    }, **stage})