import pyodbc
import json


def connect():
    c = pyodbc.connect("DSN=Autoline_direkt64;UID=kcc;PWD=kcc123")
    return c.cursor()


def convert_desc(col):
    nullable = "NULL" if col.nullable == 1 else "NOT NULL"
    if col.type_name == "CHAR":
        return f"   [{col.column_name}] [varchar]({col.length}) {nullable}"
    if col.type_name == "HEX":
        return f"   [{col.column_name}] [binary]({col.length}) {nullable}"
    if col.type_name == "INTEGER":
        return f"   [{col.column_name}] [int] {nullable}"
    if col.type_name == "DATE":
        return f"   [{col.column_name}] [datetime] {nullable}"
    if col.type_name == "NUMERIC":
        return f"   [{col.column_name}] [decimal]({col.length},{col.scale}) {nullable}"
    if col.type_name == "BIT":
        return f"   [{col.column_name}] [boolean] {nullable}"
    if col.type_name == "MEMO":
        return f"   [{col.column_name}] [text] {nullable}"
    return ", ".join(list(map(str, col)))


def convert_desc2(col):
    return ", ".join(list(map(str, col)))


# table_name = [x[2] for x in crsr.tables(tableType='VIEW')]
# open("views.txt", "w").write("\n".join(table_name))


with open("tables.txt", "r") as rh:
    tables = rh.read().split("\n")
res = {}


def tables_cols():
    crsr = connect()
    for t in tables:
        try:
            cols = crsr.columns(table=t)
            # print([x[0] for x in crsr.description])
            res[t] = [convert_desc(c) for c in cols]
            crsr.cancel()
        except pyodbc.Error as e:
            print(e)
            if t != "":
                res[t] = []
            crsr = connect()

    json.dump(res, open("schema.json", "w"), indent=2)


def pkeys():
    crsr = connect()
    for t in tables:
        try:
            cols = crsr.primaryKeys(table=t)
            # print([x[0] for x in crsr.description])
            if res.get(t) is None:
                res[t] = []
            res[t].append(
                f"   CONSTRAINT [{t}$0] PRIMARY KEY CLUSTERED (["
                + "], [".join([c.column_name for c in cols])
                + "])"
            )
            crsr.cancel()
        except pyodbc.Error as e:
            print(e)
            if t != "":
                res[t] = []
            crsr = connect()
    json.dump(res, open("pkeys.json", "w"), indent=2)


def fkeys():
    crsr = connect()
    for t in tables:
        try:
            cols = crsr.foreignKeys(table=t)
            print([x[0] for x in crsr.description])
            if res.get(t) is None:
                res[t] = []
            res[t].append([convert_desc2(c) for c in cols])
            crsr.cancel()
        except pyodbc.Error as e:
            print(e)
            if t != "":
                res[t] = []
            crsr = connect()


def tables_create():
    for t, cols in res.items():
        with open("../sql_load/schema/AUTOLINE/tables/import." + t + ".sql", "w") as wh:
            wh.write(f"CREATE TABLE [import].[{t}] (\n")
            wh.write(",\n".join(cols))
            wh.write(")\n\nGO\n")


def schema():
    tables_cols()
    pkeys()
    # fkeys()
    tables_create()