import os
import subprocess
import csv
import pymysql
import re
import json
from datetime import datetime

# ================== CONFIGURAZIONE ==================
CONFIG_PATH = os.path.expanduser("~/netgescon/agent_config.json")
with open(CONFIG_PATH) as f:
    config = json.load(f)

MDB_ROOT = config["InputDirectory"]
MYSQL_HOST = config.get("MySQLHost", "localhost")
MYSQL_DB = config.get("MySQLDatabase", "netgescon")
MYSQL_USER = config.get("MySQLUser", "user")
MYSQL_PW = config.get("MySQLPassword", "password")
DEBUG = config.get("Debug", False)
LOG_DIR = config.get("LogDirectory", os.path.expanduser("~/netgescon/log"))
LOG_PATH = os.path.join(LOG_DIR, "import_mdb_to_mysql.log")
os.makedirs(LOG_DIR, exist_ok=True)

# ================== LOGGING ==================
def log(msg):
    """Scrive un messaggio nel file di log e, se attivo, anche a video."""
    ts = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    with open(LOG_PATH, "a", encoding="utf-8") as f:
        f.write(f"[{ts}] {msg}\n")
    if DEBUG:
        print(f"[{ts}] {msg}")

# ================== MYSQL UTILS ==================
def connect_mysql():
    """Restituisce una connessione MySQL."""
    return pymysql.connect(
        host=MYSQL_HOST,
        user=MYSQL_USER,
        password=MYSQL_PW,
        database=MYSQL_DB,
        charset="utf8mb4",
        autocommit=True
    )

def table_exists(cur, name):
    """Verifica se una tabella esiste."""
    cur.execute("SHOW TABLES LIKE %s", (name,))
    return cur.fetchone() is not None

def create_table(cur, tablename, header, samples):
    """Crea la tabella su MySQL con tipi campo proposti."""
    field_types = []
    log(f"Creazione tabella `{tablename}`")
    for h, s in zip(header, samples):
        t = infer_type(s)
        field_types.append((h, t))
    columns_sql = ", ".join(f"`{h}` {t}" for h, t in field_types)
    sql = f"CREATE TABLE IF NOT EXISTS `{tablename}` (id INT AUTO_INCREMENT PRIMARY KEY, {columns_sql}) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"
    cur.execute(sql)
    log(f"Tabella `{tablename}` creata con colonne: {columns_sql}")
    return [h for h, _ in field_types]

def insert_row(cur, tablename, fields, row):
    """Inserisce una riga nella tabella MySQL, gestendo errori di tipo."""
    values = [row.get(f, None) for f in fields]
    placeholders = ", ".join(["%s"] * len(fields))
    sql = f"INSERT INTO `{tablename}` ({', '.join('`'+f+'`' for f in fields)}) VALUES ({placeholders})"
    try:
        cur.execute(sql, values)
    except Exception as e:
        log(f"[ERRORE] Insert in {tablename}: {e} | Valori: {values}")

# ================== TIPO CAMPO ==================
def infer_type(val):
    """Propone un tipo campo MySQL in base al valore di esempio."""
    if val is None or val == "":
        return "VARCHAR(255)"
    if re.fullmatch(r"\d+", val):
        return "INT"
    if re.fullmatch(r"\d+\.\d+", val):
        return "FLOAT"
    if re.fullmatch(r"\d{4}-\d{2}-\d{2}", val):
        return "DATE"
    if len(val) > 255:
        return "TEXT"
    return "VARCHAR(255)"

# ================== MDBTOOLS UTILS ==================
def process_mdb(mdb_path, cur):
    """Importa tutte le tabelle da un file MDB."""
    log(f"Inizio importazione {mdb_path}")
    try:
        # 1. Ottieni la lista tabelle
        tables = subprocess.check_output(["mdb-tables", "-1", mdb_path]).decode().split()
    except Exception as e:
        log(f"[ERRORE] Lettura tabelle MDB: {e}")
        return

    for tab in tables:
        log(f"Import tabella: {tab}")
        # 2. Estrai header e 1 record di esempio
        try:
            proc = subprocess.Popen(["mdb-export", "-H", "csv", mdb_path, tab], stdout=subprocess.PIPE)
            reader = csv.DictReader((line.decode() for line in proc.stdout), delimiter=",")
            sample = next(reader)
        except StopIteration:
            log(f"Tabella {tab} vuota, saltata.")
            continue
        except Exception as e:
            log(f"[ERRORE] Lettura tabella {tab}: {e}")
            continue

        header = list(sample.keys())
        samples = [sample[h] for h in header]
        # 3. Crea tabella se non esiste
        if not table_exists(cur, tab):
            fields = create_table(cur, tab, header, samples)
        else:
            fields = header
            log(f"Tabella `{tab}` già esistente.")

        # 4. Inserisci dati (sample + altri)
        insert_row(cur, tab, fields, sample)
        row_count = 1
        for row in reader:
            insert_row(cur, tab, fields, row)
            row_count += 1
        log(f"Tabella {tab}: {row_count} righe importate.")

def main():
    log("==== AVVIO IMPORT MDB → MYSQL ====")
    conn = connect_mysql()
    cur = conn.cursor()
    file_count = 0
    for root, _, files in os.walk(MDB_ROOT):
        for fname in files:
            if fname.lower().endswith(".mdb"):
                file_count += 1
                process_mdb(os.path.join(root, fname), cur)
    cur.close()
    conn.close()
    log(f"Importazione completata. {file_count} file MDB processati.")

if __name__ == "__main__":
    main()