from psycopg.rows import dict_row, Row
from .connection import g_conn_dict as conn
from .s0_base import *
from .operation import *
from .change_set import ChangeSet

def add_reservoir(name: str, id: str, x: float, y: float, head: float) -> ChangeSet:
    if is_node(name, id):
        return

    with conn[name].cursor() as cur:
        sql = f"insert into _node (id, type) values ('{id}', 'RESERVOIR');"
        sql += f" insert into reservoirs (id, head) values ('{id}', {head});"
        sql += f" insert into coordinates (node, coord) values ('{id}', '({x}, {y})');"
        cur.execute(sql)

        redo = sql.replace("'", '"')
        undo = f'delete from coordinates where node = "{id}";'
        undo += f' delete from reservoirs where id = "{id}";'
        undo += f' delete from _node where id = "{id}";'
        add_operation(name, redo, undo)

    change = ChangeSet()
    change.add('reservoir', id)
    return change

def delete_reservoir(name: str, id: str) -> ChangeSet:
    if not is_reservoir(name, id):
        return

    with conn[name].cursor(row_factory=dict_row) as cur:
        cur.execute(f"select * from reservoirs where id = '{id}'")
        row = cur.fetchone()
        if row == None:
            return

        head = row['head']
        pattern = 'NULL' if row['pattern'] == None else row['pattern']
        pattern = f'"{pattern}"' if pattern != 'NULL' else pattern

        cur.execute(f"select * from coordinates where node = '{id}'")
        row = cur.fetchone()
        if row == None:
            return

        coord = row['coord']

        sql = f"delete from coordinates where node = '{id}';"
        sql += f" delete from reservoirs where id = '{id}';"
        sql += f" delete from _node where id = '{id}';"
        cur.execute(sql)

        redo = sql.replace("'", '"')
        undo = f'insert into _node (id, type) values ("{id}", "RESERVOIR");'
        undo += f' insert into reservoirs (id, head, pattern) values ("{id}", {head}, {pattern});'
        undo += f' insert into coordinates (node, coord) values ("{id}", "{coord}");'
        add_operation(name, redo, undo)

    change = ChangeSet()
    change.delete('reservoir', id)
    return change

def _get_reservoir(name: str, id: str) -> Row | None:
    with conn[name].cursor(row_factory=dict_row) as cur:
        cur.execute(f"select head, pattern from reservoirs where id = '{id}'")
        return cur.fetchone()

def get_reservoir_head(name: str, id: str) -> float | None:
    row = _get_reservoir(name, id)
    return float(row['head']) if row != None else None

def get_reservoir_pattern(name: str, id: str) -> str | None:
    row = _get_reservoir(name, id)
    if row != None:
        return row['pattern'] if row['pattern'] != None else 'NULL'
    else:
        return None

def _to_point(coord: str) -> dict[str, float]:
    coord = coord.removeprefix('(')
    coord = coord.removesuffix(')')
    coord = coord.split(',')
    return { 'x': float(coord[0]), 'y': float(coord[1]) }

def get_reservoir_coord(name: str, id: str) -> dict[str, float] | None:
    with conn[name].cursor(row_factory=dict_row) as cur:
        cur.execute(f"select * from coordinates where node = '{id}'")
        row = cur.fetchone()
        if row == None:
            return None
        
        coord = str(row['coord'])
        return _to_point(coord)

def set_reservoir_head(name: str, id: str, head: float) -> ChangeSet:
    if not is_reservoir(name, id):
        return

    old = get_reservoir_head(name, id)
    if old == None:
        return

    with conn[name].cursor() as cur:
        sql = f"update reservoirs set head = {head} where id = '{id}'"
        cur.execute(sql)
        redo = sql.replace("'", '"')
        undo = f'update reservoirs set head = {old} where id = "{id}"'
        add_operation(name, redo, undo)

    change = ChangeSet()
    change.update('reservoir', id, 'head', 'float', str(head))
    return change

def set_reservoir_pattern(name: str, id: str, pattern: str) -> ChangeSet:
    if not is_reservoir(name, id):
        return
    if not is_pattern(name, id):
        return

    old = get_reservoir_pattern(name, id)
    if old == None:
        return

    old = f'"{old}"' if old != 'NULL' else old

    with conn[name].cursor() as cur:
        sql = f"update reservoirs set pattern = '{pattern}' where id = '{id}'"
        cur.execute(sql)
        redo = sql.replace("'", '"')
        undo = f'update reservoirs set pattern = {old} where id = "{id}"'
        add_operation(name, redo, undo)

    change = ChangeSet()
    change.update('reservoir', id, 'pattern', 'str', str(pattern))
    return change


def set_reservoir_coord(name: str, id: str, x: float, y: float) -> ChangeSet:
    if not is_reservoir(name, id):
        return

    old = get_reservoir_coord(name, id)
    if old == None:
        return
    old_x, old_y = old['x'], old['y']

    with conn[name].cursor() as cur:
        sql = f"update coordinates set coord = '({x},{y})' where node = '{id}'"
        cur.execute(sql)

        redo = sql.replace("'", '"')
        undo = f'update coordinates set coord = "({old_x},{old_y})" where node = "{id}"'
        add_operation(name, redo, undo)

    change = ChangeSet()
    change.update('reservoir', id, 'coord', 'point', str({'x': x, 'y': y}))
    return change