# -*- coding: utf-8 -*-

import os
import json
import unittest
from tempfile import NamedTemporaryFile
from pgbouncemgr.logger import *
from pgbouncemgr.state import *
from pgbouncemgr.state_store import *


def make_test_file_path(filename):
    testfiles_path = os.path.dirname(os.path.realpath(__file__))
    return os.path.join(testfiles_path, "testfiles", filename)

class StateStoreTests(unittest.TestCase):
    def test_GivenNonExistingStateFile_OnLoad_StateStoreDoesNotLoadState(self):
        state = State(Logger())
        before = state.export()
        StateStore("/non-existent/state.json", state)
        after = state.export()

        self.assertEqual(before, after)

    def test_GivenExistingStateFile_ContainingInvalidJson_OnLoad_StateStoreDoesNotLoadState(self):
        state = State(Logger())
        before = state.export()
        StateStore(make_test_file_path("invalid.json"), state)
        after = state.export()

        self.assertEqual(before, after)

    def test_GivenExistingStateFile_OnLoad_StateStoreUpdatesState(self):
        state = State(Logger())

        # These are the fields as defined in the state.json file.
        expected = state.export()
        expected["system_id"] = "A"
        expected["timeline_id"] = 42
        expected["leader_node_id"] = None # because leader node id 'nodeA' does not exist.
        expected["active_pgbouncer_config"] = None # because stored /my/config.ini does not exist.

        StateStore(make_test_file_path("state.json"), state)

        self.assertEqual(expected, state.export())

    def test_GivenState_OnSave_StateStoreStoresState(self):
        try:
            state = State(Logger())
            tmpfile = NamedTemporaryFile(delete=False)
            StateStore(tmpfile.name, state).store()

            with open(tmpfile.name, 'r') as stream:
                stored = json.load(stream)
            self.assertEqual(state.export(), stored)
        except Exception as exception:
            self.fail("Unexpected exception: %s" % str(exception))
        finally:
            if tmpfile and os.path.exists(tmpfile.name):
                os.unlink(tmpfile.name)

    def test_GivenError_OnSave_ExceptionIsRaised(self):
        state = State(Logger())
        with self.assertRaises(StateStoreException) as context:
            StateStore("/tmp/path/that/does/not/exist/fofr/statefile", state).store()
        self.assertIn("Storing state to file", str(context.exception))
        self.assertIn("failed: FileNotFoundError", str(context.exception))