import os

import frappe
from frappe.database.db_manager import DbManager

expected_settings_10_2_earlier = {
	"innodb_file_format": "Barracuda",
	"innodb_file_per_table": "ON",
	"innodb_large_prefix": "ON",
	"character_set_server": "utf8mb4",
	"collation_server": "utf8mb4_unicode_ci",
}

expected_settings_10_3_later = {
	"character_set_server": "utf8mb4",
	"collation_server": "utf8mb4_unicode_ci",
}


def get_mariadb_versions():
	# MariaDB classifies their versions as Major (1st and 2nd number), and Minor (3rd number)
	# Example: Version 10.3.13 is Major Version = 10.3, Minor Version = 13
	mariadb_variables = frappe._dict(frappe.db.sql("""show variables"""))
	version_string = mariadb_variables.get("version").split("-")[0]
	versions = {}
	versions["major"] = version_string.split(".")[0] + "." + version_string.split(".")[1]
	versions["minor"] = version_string.split(".")[2]
	return versions


def setup_database(force, source_sql, verbose, no_mariadb_socket=False):
	frappe.local.session = frappe._dict({"user": "Administrator"})

	db_name = frappe.local.conf.db_name
	root_conn = get_root_connection(frappe.flags.root_login, frappe.flags.root_password)
	dbman = DbManager(root_conn)
	dbman_kwargs = {}
	if no_mariadb_socket:
		dbman_kwargs["host"] = "%"

	if force or (db_name not in dbman.get_database_list()):
		dbman.delete_user(db_name, **dbman_kwargs)
		dbman.drop_database(db_name)
	else:
		raise Exception(f"Database {db_name} already exists")

	dbman.create_user(db_name, frappe.conf.db_password, **dbman_kwargs)
	if verbose:
		print("Created user %s" % db_name)

	dbman.create_database(db_name)
	if verbose:
		print("Created database %s" % db_name)

	dbman.grant_all_privileges(db_name, db_name, **dbman_kwargs)
	dbman.flush_privileges()
	if verbose:
		print(f"Granted privileges to user {db_name} and database {db_name}")

	# close root connection
	root_conn.close()

	bootstrap_database(db_name, verbose, source_sql)


def drop_user_and_database(db_name, root_login, root_password):
	frappe.local.db = get_root_connection(root_login, root_password)
	dbman = DbManager(frappe.local.db)
	dbman.drop_database(db_name)
	dbman.delete_user(db_name, host="%")
	dbman.delete_user(db_name)


def bootstrap_database(db_name, verbose, source_sql=None):
	import sys

	frappe.connect(db_name=db_name)
	if not check_database_settings():
		print("Database settings do not match expected values; stopping database setup.")
		sys.exit(1)

	import_db_from_sql(source_sql, verbose)

	frappe.connect(db_name=db_name)
	if "tabDefaultValue" not in frappe.db.get_tables(cached=False):
		from click import secho

		secho(
			"Table 'tabDefaultValue' missing in the restored site. "
			"Database not installed correctly, this can due to lack of "
			"permission, or that the database name exists. Check your mysql"
			" root password, validity of the backup file or use --force to"
			" reinstall",
			fg="red",
		)
		sys.exit(1)


def import_db_from_sql(source_sql=None, verbose=False):
	if verbose:
		print("Starting database import...")
	db_name = frappe.conf.db_name
	if not source_sql:
		source_sql = os.path.join(os.path.dirname(__file__), "framework_mariadb.sql")
	DbManager(frappe.local.db).restore_database(db_name, source_sql, db_name, frappe.conf.db_password)
	if verbose:
		print("Imported from database %s" % source_sql)


def check_database_settings():
	versions = get_mariadb_versions()
	if versions["major"] <= "10.2":
		expected_variables = expected_settings_10_2_earlier
	else:
		expected_variables = expected_settings_10_3_later

	mariadb_variables = frappe._dict(frappe.db.sql("show variables"))
	# Check each expected value vs. actuals:
	result = True
	for key, expected_value in expected_variables.items():
		if mariadb_variables.get(key) != expected_value:
			print(
				"For key %s. Expected value %s, found value %s"
				% (key, expected_value, mariadb_variables.get(key))
			)
			result = False
	if not result:
		print(
			(
				"=" * 80 + "\n"
				"Creation of your site - {x} failed because MariaDB is not properly {sep}"
				"configured.  If using version 10.2.x or earlier, make sure you use the {sep}"
				"the Barracuda storage engine. {sep}{sep}"
				"Please verify the settings above in MariaDB's my.cnf.  Restart MariaDB.  And {sep}"
				"then run `bench new-site {x}` again.{sep2}"
				""
				"=" * 80
			).format(x=frappe.local.site, sep2="\n" * 2, sep="\n")
		)

	return result


def get_root_connection(root_login, root_password):
	import getpass

	if not frappe.local.flags.root_connection:
		if not root_login:
			root_login = "root"

		if not root_password:
			root_password = frappe.conf.get("root_password") or None

		if not root_password:
			root_password = getpass.getpass("MySQL root password: ")

		frappe.local.flags.root_connection = frappe.database.get_db(
			user=root_login, password=root_password
		)

	return frappe.local.flags.root_connection