from sqlglot.optimizer.qualify import qualify
from sqlglot.optimizer.normalize import normalize
from sqlglot.optimizer import optimize
from sqlglot import exp
from sqlglot import parse_one, diff
from sqlglot.errors import ParseError, OptimizeError
import sqlite3
import threading
from ortools.linear_solver import pywraplp
from sqlglot.diff import Insert, Remove, Update, Move, Keep
from sqlglot.expressions import Alias, TableAlias
from utils import SQLITE_DB_DIR


def get_bird_db(db_name):
    return (SQLITE_DB_DIR / db_name / f"{db_name}.sqlite").resolve()

class QueryThread(threading.Thread):
    def __init__(self, query, db_str):
        threading.Thread.__init__(self)
        self.db_str = db_str
        self.query = query
        self.results = 'Failed to run query'
        self.daemon = True # this is maybe needed to ensure that still-alive-threads end when main ends

    def run(self):
        conn = sqlite3.connect(self.db_str)
        cursor = conn.cursor()
        try:
            cursor.execute(self.query)
            self.results = cursor.fetchall()
        except (sqlite3.OperationalError, sqlite3.ProgrammingError) as e:
            self.results = "Failed to run query"
        conn.close()

def execute_sql(query_str, db_str):
    TIMEOUT_SECONDS = 45.0
    try:
        db_location = get_bird_db(db_str)
        # a bit of a hack - using a thread to run queries so that i can set a timeout.
        thread = QueryThread(query_str, db_location)
        thread.start()
        thread.join(TIMEOUT_SECONDS)
        if not thread.is_alive():
            generated_result = set([tuple(str(c) for c in r) for r in thread.results])
        else:
            generated_result = "Failed to run query"
    except (sqlite3.OperationalError, sqlite3.ProgrammingError) as e:
        generated_result = "Failed to run query"
    return generated_result


def normalize_commutative_ordering(expression):
    normalize_types = {exp.Add, exp.SafeMultiply, exp.Select}

    for node in expression.walk(bfs=True):
        if type(node) in normalize_types:

            operands = [node.this, node.args.get('expression')]
            # this sorting isn't so proper/meaningful, we just want _some_ order to be present to make comparisons easier.
            try:
                operands.sort(key=lambda x: x.sql())
                node.set(arg_key='this', value=operands[0])
                node.set(arg_key='expression', value=operands[1])
            except Exception as e:
                # Handle cases where sql() conversion might fail or not be appropriate
                # print(f"Could not sort operands for node {node}: {e}")
                pass
        # continue
        # # print(expression)
        # # print(node)
        # # normalize_commutative_ordering(node)
    return expression


def remove_table_aliases(sql):
    # remove aliases from tables, assign any columns referring to table aliases with direct references to tables
    tab_aliases = {}
    for table_exp in sql.find_all(exp.Table):
        if table_exp.alias:
            tab_aliases[table_exp.alias] = table_exp
    for node in sql.walk():
        if isinstance(node, exp.Table) and node.alias:
            node.set("alias", None)
        elif isinstance(node, exp.Column) and node.table:

            if node.table in tab_aliases:
                node.args['table'] = exp.Table(this=tab_aliases[node.table], quoted=node.args['table'].quoted)

    # re-order any content where the order shouldn't matterg

    return sql


def cleanup_query(query, schema):
    query = query.replace("`", "\"")
    try:
        parse = parse_one(query)
    except ParseError as e:
        return None
    try:
        try:
            qual = qualify(parse, dialect='sqlite', schema=schema)
        except OptimizeError as e:
            qual = qualify(parse, dialect='sqlite')
    except OptimizeError as e:  # OptimizeError,
        return None
    opt_norm = optimize(normalize(qual, dnf=True))

    cleaner_sql = remove_table_aliases(opt_norm)
    cleaner_sql = normalize_commutative_ordering(cleaner_sql)
    return cleaner_sql


def get_nonalias_diff(q1, q2, schema):
    try:
        clean_q1 = cleanup_query(q1, schema)
        clean_q2 = cleanup_query(q2, schema)
    except Exception as e:
        # print(e)
        return None, None
    if clean_q1 is None or clean_q2 is None:
        return None, None
    totalcount = 0
    diffcount = 0
    for d in diff(clean_q1, clean_q2):
        totalcount += 1
        if isinstance(d, Keep):
            continue
        elif isinstance(d, Remove) or isinstance(d, Insert):
            if not (isinstance(d.expression, Alias) or isinstance(d.expression,
                                                                  TableAlias)):  # or isinstance(d.expression, ColumnAlias)):
                diffcount += 1
        elif isinstance(d, Update) or isinstance(d, Move):
            # there is some edge case where we get an update but the source and target are equivalent? if so just ignore.
            if d.source == d.target:
                continue
            if not (isinstance(d.source, Alias) or isinstance(d.source,
                                                              TableAlias)):  # or isinstance(d.source, ColumnAlias)):
                diffcount += 1
            elif not (isinstance(d.target, Alias) or isinstance(d.target,
                                                                TableAlias)):  # or isinstance(d.target, ColumnAlias)):
                diffcount += 1
    return diffcount, totalcount


def sql_diff_sim(q1, q2, schema):
    diff, tot = get_nonalias_diff(q1, q2, schema)
    if diff is None or tot is None:
        return None
    return 1 - (diff / tot)

def solve_optimal_mapping(score_matrix, debug_solver: bool = False):
    # score matrix should be GT x PRED
    solver = pywraplp.Solver.CreateSolver("SCIP")

    var_list = []
    to_gt_constraints = []
    objective_terms = []
    p_list = [[] for _ in range(len(score_matrix[0]))]
    for i in range(len(score_matrix)):
        c_list = []
        for j, scoreval in enumerate(score_matrix[i]):
            new_var = solver.IntVar(0, 1, "")
            var_list.append((new_var, i, j))
            c_list.append(new_var)
            p_list[j].append(new_var)
            objective_terms.append(new_var * scoreval)
        solver.Add(sum(c_list) <= 1)
    for pl in p_list:
        solver.Add(sum(pl) <= 1)
    solver.Maximize(sum(objective_terms))

    status = solver.Solve()

    if debug_solver:
        if status == pywraplp.Solver.INFEASIBLE:
            print("INFEASIBLE")
        elif status == pywraplp.Solver.FEASIBLE:
            print("FEASIBLE")

    soln_gt_to_pred = {}
    for var, gt_ind, pred_ind in var_list:
        if var.solution_value() == 1:
            soln_gt_to_pred[gt_ind] = pred_ind
    soln_total_score = solver.Objective().Value()
    return soln_gt_to_pred