# -*- coding: utf-8 -*-
# Copyright (c) 2018, Frappe Technologies Pvt. Ltd. and Contributors
# MIT License. See license.txt
from __future__ import unicode_literals

from collections import Counter
import datetime
import inspect
import json
import re
import time
import traceback
import frappe
import sqlparse
from pygments import highlight
from pygments.lexers import PythonLexer
from pygments.formatters import HtmlFormatter

from frappe import _

RECORDER_INTERCEPT_FLAG = "recorder-intercept"
RECORDER_REQUEST_SPARSE_HASH = "recorder-requests-sparse"
RECORDER_REQUEST_HASH = "recorder-requests"


def sql(*args, **kwargs):
	start_time = time.time()
	result = frappe.db._sql(*args, **kwargs)
	end_time = time.time()

	stack = list(get_current_stack_frames())

	if frappe.db.db_type == 'postgres':
		query = frappe.db._cursor.query
	else:
		query = frappe.db._cursor._executed

	query = sqlparse.format(query.strip(), keyword_case="upper", reindent=True)

	# Collect EXPLAIN for executed query
	if query.lower().strip().split()[0] in ("select", "update", "delete"):
		# Only SELECT/UPDATE/DELETE queries can be "EXPLAIN"ed
		explain_result = frappe.db._sql("EXPLAIN {}".format(query), as_dict=True)
	else:
		explain_result = []

	data = {
		"query": query,
		"stack": stack,
		"explain_result": explain_result,
		"time": start_time,
		"duration": float("{:.3f}".format((end_time - start_time) * 1000)),
	}

	frappe.local._recorder.register(data)
	return result


def get_current_stack_frames():
	current = inspect.currentframe()
	frames = inspect.getouterframes(current, context=10)
	for frame, filename, lineno, function, context, index in list(reversed(frames))[:-2]:
		if "/apps/" in filename:
			yield {
				"filename": re.sub(".*/apps/", "", filename),
				"lineno": lineno,
				"function": function,
				"context": "".join(context),
				"index": index,
				"locals": json.dumps(frame.f_locals, skipkeys=True, default=str)
			}


def record():
	if __debug__:
		if frappe.cache().get_value(RECORDER_INTERCEPT_FLAG):
			frappe.local._recorder = Recorder()


def dump():
	if __debug__:
		if hasattr(frappe.local, "_recorder"):
			frappe.local._recorder.dump()


class Recorder():
	def __init__(self):
		self.uuid = frappe.generate_hash(length=10)
		self.time = datetime.datetime.now()
		self.calls = []
		self.path = frappe.request.path
		self.cmd = frappe.local.form_dict.cmd or ""
		self.method = frappe.request.method
		self.headers = dict(frappe.local.request.headers)
		self.form_dict = frappe.local.form_dict
		_patch()

	def register(self, data):
		self.calls.append(data)

	def dump(self):
		request_data = {
			"uuid": self.uuid,
			"path": self.path,
			"cmd": self.cmd,
			"time": self.time,
			"queries": len(self.calls),
			"time_queries": float("{:0.3f}".format(sum(call["duration"] for call in self.calls))),
			"duration": float("{:0.3f}".format((datetime.datetime.now() - self.time).total_seconds() * 1000)),
			"method": self.method,
		}
		frappe.cache().hset(RECORDER_REQUEST_SPARSE_HASH, self.uuid, request_data)
		frappe.publish_realtime(event="recorder-dump-event", message=json.dumps(request_data, default=str))

		self.mark_duplicates()

		request_data["calls"] = self.calls
		request_data["headers"] = self.headers
		request_data["form_dict"] = self.form_dict
		frappe.cache().hset(RECORDER_REQUEST_HASH, self.uuid, request_data)

	def mark_duplicates(self):
		counts = Counter([call["query"] for call in self.calls])
		for index, call in enumerate(self.calls):
			call["index"] = index
			call["exact_copies"] = counts[call["query"]]


def _patch():
	frappe.db._sql = frappe.db.sql
	frappe.db.sql = sql


def do_not_record(function):
	def wrapper(*args, **kwargs):
		if hasattr(frappe.local, "_recorder"):
			del frappe.local._recorder
			frappe.db.sql = frappe.db._sql
		return function(*args, **kwargs)
	return wrapper


def administrator_only(function):
	def wrapper(*args, **kwargs):
		if frappe.session.user != "Administrator":
			frappe.throw(_("Only Administrator is allowed to use Recorder"))
		return function(*args, **kwargs)
	return wrapper


@frappe.whitelist()
@do_not_record
@administrator_only
def status(*args, **kwargs):
	return bool(frappe.cache().get_value(RECORDER_INTERCEPT_FLAG))


@frappe.whitelist()
@do_not_record
@administrator_only
def start(*args, **kwargs):
	frappe.cache().set_value(RECORDER_INTERCEPT_FLAG, 1)


@frappe.whitelist()
@do_not_record
@administrator_only
def stop(*args, **kwargs):
	frappe.cache().delete_value(RECORDER_INTERCEPT_FLAG)


@frappe.whitelist()
@do_not_record
@administrator_only
def get(uuid=None, *args, **kwargs):
	if uuid:
		result = frappe.cache().hget(RECORDER_REQUEST_HASH, uuid)
		lexer = PythonLexer(tabsize=4)
		for call in result["calls"]:
			for stack in call["stack"]:
				formatter = HtmlFormatter(noclasses=True, hl_lines=[stack["index"] + 1])
				stack["context"] = highlight(stack["context"], lexer, formatter)
	else:
		result = list(frappe.cache().hgetall(RECORDER_REQUEST_SPARSE_HASH).values())
	return result


@frappe.whitelist()
@do_not_record
@administrator_only
def delete(*args, **kwargs):
	frappe.cache().delete_value(RECORDER_REQUEST_SPARSE_HASH)
	frappe.cache().delete_value(RECORDER_REQUEST_HASH)