import json
import unittest
from datetime import UTC, datetime
from typing import Any
from unittest.mock import MagicMock, Mock

import pytest

from core.trigger.constants import TRIGGER_SCHEDULE_NODE_TYPE
from core.workflow.nodes.trigger_schedule.entities import VisualConfig
from core.workflow.nodes.trigger_schedule.exc import ScheduleConfigError
from libs.schedule_utils import calculate_next_run_at, convert_12h_to_24h
from models.workflow import Workflow, WorkflowType
from services.trigger.schedule_service import ScheduleService


class TestScheduleService(unittest.TestCase):
    """Test cases for ScheduleService class."""

    def test_calculate_next_run_at_valid_cron(self):
        """Test calculating next run time with valid cron expression."""
        # Test daily cron at 10:30 AM
        cron_expr = "30 10 * * *"
        timezone = "UTC"
        base_time = datetime(2025, 8, 29, 9, 0, 0, tzinfo=UTC)

        next_run = calculate_next_run_at(cron_expr, timezone, base_time)

        assert next_run is not None
        assert next_run.hour == 10
        assert next_run.minute == 30
        assert next_run.day == 29

    def test_calculate_next_run_at_with_timezone(self):
        """Test calculating next run time with different timezone."""
        cron_expr = "0 9 * * *"  # 9:00 AM
        timezone = "America/New_York"
        base_time = datetime(2025, 8, 29, 12, 0, 0, tzinfo=UTC)  # 8:00 AM EDT

        next_run = calculate_next_run_at(cron_expr, timezone, base_time)

        assert next_run is not None
        # 9:00 AM EDT = 13:00 UTC (during EDT)
        expected_utc_hour = 13
        assert next_run.hour == expected_utc_hour

    def test_calculate_next_run_at_with_last_day_of_month(self):
        """Test calculating next run time with 'L' (last day) syntax."""
        cron_expr = "0 10 L * *"  # 10:00 AM on last day of month
        timezone = "UTC"
        base_time = datetime(2025, 2, 15, 9, 0, 0, tzinfo=UTC)

        next_run = calculate_next_run_at(cron_expr, timezone, base_time)

        assert next_run is not None
        # February 2025 has 28 days
        assert next_run.day == 28
        assert next_run.month == 2

    def test_calculate_next_run_at_invalid_cron(self):
        """Test calculating next run time with invalid cron expression."""
        cron_expr = "invalid cron"
        timezone = "UTC"

        with pytest.raises(ValueError):
            calculate_next_run_at(cron_expr, timezone)

    def test_calculate_next_run_at_invalid_timezone(self):
        """Test calculating next run time with invalid timezone."""
        from pytz import UnknownTimeZoneError

        cron_expr = "30 10 * * *"
        timezone = "Invalid/Timezone"

        with pytest.raises(UnknownTimeZoneError):
            calculate_next_run_at(cron_expr, timezone)


class TestVisualToCron(unittest.TestCase):
    """Test cases for visual configuration to cron conversion."""

    def test_visual_to_cron_hourly(self):
        """Test converting hourly visual config to cron."""
        visual_config = VisualConfig(on_minute=15)
        result = ScheduleService.visual_to_cron("hourly", visual_config)
        assert result == "15 * * * *"

    def test_visual_to_cron_daily(self):
        """Test converting daily visual config to cron."""
        visual_config = VisualConfig(time="2:30 PM")
        result = ScheduleService.visual_to_cron("daily", visual_config)
        assert result == "30 14 * * *"

    def test_visual_to_cron_weekly(self):
        """Test converting weekly visual config to cron."""
        visual_config = VisualConfig(
            time="10:00 AM",
            weekdays=["mon", "wed", "fri"],
        )
        result = ScheduleService.visual_to_cron("weekly", visual_config)
        assert result == "0 10 * * 1,3,5"

    def test_visual_to_cron_monthly_with_specific_days(self):
        """Test converting monthly visual config with specific days."""
        visual_config = VisualConfig(
            time="11:30 AM",
            monthly_days=[1, 15],
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        assert result == "30 11 1,15 * *"

    def test_visual_to_cron_monthly_with_last_day(self):
        """Test converting monthly visual config with last day using 'L' syntax."""
        visual_config = VisualConfig(
            time="11:30 AM",
            monthly_days=[1, "last"],
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        assert result == "30 11 1,L * *"

    def test_visual_to_cron_monthly_only_last_day(self):
        """Test converting monthly visual config with only last day."""
        visual_config = VisualConfig(
            time="9:00 PM",
            monthly_days=["last"],
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        assert result == "0 21 L * *"

    def test_visual_to_cron_monthly_with_end_days_and_last(self):
        """Test converting monthly visual config with days 29, 30, 31 and 'last'."""
        visual_config = VisualConfig(
            time="3:45 PM",
            monthly_days=[29, 30, 31, "last"],
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        # Should have 29,30,31,L - the L handles all possible last days
        assert result == "45 15 29,30,31,L * *"

    def test_visual_to_cron_invalid_frequency(self):
        """Test converting with invalid frequency."""
        with pytest.raises(ScheduleConfigError, match="Unsupported frequency: invalid"):
            ScheduleService.visual_to_cron("invalid", VisualConfig())

    def test_visual_to_cron_weekly_no_weekdays(self):
        """Test converting weekly with no weekdays specified."""
        visual_config = VisualConfig(time="10:00 AM")
        with pytest.raises(ScheduleConfigError, match="Weekdays are required for weekly schedules"):
            ScheduleService.visual_to_cron("weekly", visual_config)

    def test_visual_to_cron_hourly_no_minute(self):
        """Test converting hourly with no on_minute specified."""
        visual_config = VisualConfig()  # on_minute defaults to 0
        result = ScheduleService.visual_to_cron("hourly", visual_config)
        assert result == "0 * * * *"  # Should use default value 0

    def test_visual_to_cron_daily_no_time(self):
        """Test converting daily with no time specified."""
        visual_config = VisualConfig(time=None)
        with pytest.raises(ScheduleConfigError, match="time is required for daily schedules"):
            ScheduleService.visual_to_cron("daily", visual_config)

    def test_visual_to_cron_weekly_no_time(self):
        """Test converting weekly with no time specified."""
        visual_config = VisualConfig(weekdays=["mon"])
        visual_config.time = None  # Override default
        with pytest.raises(ScheduleConfigError, match="time is required for weekly schedules"):
            ScheduleService.visual_to_cron("weekly", visual_config)

    def test_visual_to_cron_monthly_no_time(self):
        """Test converting monthly with no time specified."""
        visual_config = VisualConfig(monthly_days=[1])
        visual_config.time = None  # Override default
        with pytest.raises(ScheduleConfigError, match="time is required for monthly schedules"):
            ScheduleService.visual_to_cron("monthly", visual_config)

    def test_visual_to_cron_monthly_duplicate_days(self):
        """Test monthly with duplicate days should be deduplicated."""
        visual_config = VisualConfig(
            time="10:00 AM",
            monthly_days=[1, 15, 1, 15, 31],  # Duplicates
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        assert result == "0 10 1,15,31 * *"  # Should be deduplicated

    def test_visual_to_cron_monthly_unsorted_days(self):
        """Test monthly with unsorted days should be sorted."""
        visual_config = VisualConfig(
            time="2:30 PM",
            monthly_days=[20, 5, 15, 1, 10],  # Unsorted
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        assert result == "30 14 1,5,10,15,20 * *"  # Should be sorted

    def test_visual_to_cron_weekly_all_weekdays(self):
        """Test weekly with all weekdays."""
        visual_config = VisualConfig(
            time="8:00 AM",
            weekdays=["sun", "mon", "tue", "wed", "thu", "fri", "sat"],
        )
        result = ScheduleService.visual_to_cron("weekly", visual_config)
        assert result == "0 8 * * 0,1,2,3,4,5,6"

    def test_visual_to_cron_hourly_boundary_values(self):
        """Test hourly with boundary minute values."""
        # Minimum value
        visual_config = VisualConfig(on_minute=0)
        result = ScheduleService.visual_to_cron("hourly", visual_config)
        assert result == "0 * * * *"

        # Maximum value
        visual_config = VisualConfig(on_minute=59)
        result = ScheduleService.visual_to_cron("hourly", visual_config)
        assert result == "59 * * * *"

    def test_visual_to_cron_daily_midnight_noon(self):
        """Test daily at special times (midnight and noon)."""
        # Midnight
        visual_config = VisualConfig(time="12:00 AM")
        result = ScheduleService.visual_to_cron("daily", visual_config)
        assert result == "0 0 * * *"

        # Noon
        visual_config = VisualConfig(time="12:00 PM")
        result = ScheduleService.visual_to_cron("daily", visual_config)
        assert result == "0 12 * * *"

    def test_visual_to_cron_monthly_mixed_with_last_and_duplicates(self):
        """Test monthly with mixed days, 'last', and duplicates."""
        visual_config = VisualConfig(
            time="11:45 PM",
            monthly_days=[15, 1, "last", 15, 30, 1, "last"],  # Mixed with duplicates
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        assert result == "45 23 1,15,30,L * *"  # Deduplicated and sorted with L at end

    def test_visual_to_cron_weekly_single_day(self):
        """Test weekly with single weekday."""
        visual_config = VisualConfig(
            time="6:30 PM",
            weekdays=["sun"],
        )
        result = ScheduleService.visual_to_cron("weekly", visual_config)
        assert result == "30 18 * * 0"

    def test_visual_to_cron_monthly_all_possible_days(self):
        """Test monthly with all 31 days plus 'last'."""
        all_days = list(range(1, 32)) + ["last"]
        visual_config = VisualConfig(
            time="12:01 AM",
            monthly_days=all_days,
        )
        result = ScheduleService.visual_to_cron("monthly", visual_config)
        expected_days = ",".join([str(i) for i in range(1, 32)]) + ",L"
        assert result == f"1 0 {expected_days} * *"

    def test_visual_to_cron_monthly_no_days(self):
        """Test monthly without any days specified should raise error."""
        visual_config = VisualConfig(time="10:00 AM", monthly_days=[])
        with pytest.raises(ScheduleConfigError, match="Monthly days are required for monthly schedules"):
            ScheduleService.visual_to_cron("monthly", visual_config)

    def test_visual_to_cron_weekly_empty_weekdays_list(self):
        """Test weekly with empty weekdays list should raise error."""
        visual_config = VisualConfig(time="10:00 AM", weekdays=[])
        with pytest.raises(ScheduleConfigError, match="Weekdays are required for weekly schedules"):
            ScheduleService.visual_to_cron("weekly", visual_config)


class TestParseTime(unittest.TestCase):
    """Test cases for time parsing function."""

    def test_parse_time_am(self):
        """Test parsing AM time."""
        hour, minute = convert_12h_to_24h("9:30 AM")
        assert hour == 9
        assert minute == 30

    def test_parse_time_pm(self):
        """Test parsing PM time."""
        hour, minute = convert_12h_to_24h("2:45 PM")
        assert hour == 14
        assert minute == 45

    def test_parse_time_noon(self):
        """Test parsing 12:00 PM (noon)."""
        hour, minute = convert_12h_to_24h("12:00 PM")
        assert hour == 12
        assert minute == 0

    def test_parse_time_midnight(self):
        """Test parsing 12:00 AM (midnight)."""
        hour, minute = convert_12h_to_24h("12:00 AM")
        assert hour == 0
        assert minute == 0

    def test_parse_time_invalid_format(self):
        """Test parsing invalid time format."""
        with pytest.raises(ValueError, match="Invalid time format"):
            convert_12h_to_24h("25:00")

    def test_parse_time_invalid_hour(self):
        """Test parsing invalid hour."""
        with pytest.raises(ValueError, match="Invalid hour: 13"):
            convert_12h_to_24h("13:00 PM")

    def test_parse_time_invalid_minute(self):
        """Test parsing invalid minute."""
        with pytest.raises(ValueError, match="Invalid minute: 60"):
            convert_12h_to_24h("10:60 AM")

    def test_parse_time_empty_string(self):
        """Test parsing empty string."""
        with pytest.raises(ValueError, match="Time string cannot be empty"):
            convert_12h_to_24h("")

    def test_parse_time_invalid_period(self):
        """Test parsing invalid period."""
        with pytest.raises(ValueError, match="Invalid period"):
            convert_12h_to_24h("10:30 XM")


class TestExtractScheduleConfig(unittest.TestCase):
    """Test cases for extracting schedule configuration from workflow."""

    def test_extract_schedule_config_with_cron_mode(self):
        """Test extracting schedule config in cron mode."""
        workflow = Mock(spec=Workflow)
        workflow.graph_dict = {
            "nodes": [
                {
                    "id": "schedule-node",
                    "data": {
                        "type": "trigger-schedule",
                        "mode": "cron",
                        "cron_expression": "0 10 * * *",
                        "timezone": "America/New_York",
                    },
                }
            ]
        }

        config = ScheduleService.extract_schedule_config(workflow)

        assert config is not None
        assert config.node_id == "schedule-node"
        assert config.cron_expression == "0 10 * * *"
        assert config.timezone == "America/New_York"

    def test_extract_schedule_config_with_visual_mode(self):
        """Test extracting schedule config in visual mode."""
        workflow = Mock(spec=Workflow)
        workflow.graph_dict = {
            "nodes": [
                {
                    "id": "schedule-node",
                    "data": {
                        "type": "trigger-schedule",
                        "mode": "visual",
                        "frequency": "daily",
                        "visual_config": {"time": "10:30 AM"},
                        "timezone": "UTC",
                    },
                }
            ]
        }

        config = ScheduleService.extract_schedule_config(workflow)

        assert config is not None
        assert config.node_id == "schedule-node"
        assert config.cron_expression == "30 10 * * *"
        assert config.timezone == "UTC"

    def test_extract_schedule_config_no_schedule_node(self):
        """Test extracting config when no schedule node exists."""
        workflow = Mock(spec=Workflow)
        workflow.graph_dict = {
            "nodes": [
                {
                    "id": "other-node",
                    "data": {"type": "llm"},
                }
            ]
        }

        config = ScheduleService.extract_schedule_config(workflow)
        assert config is None

    def test_extract_schedule_config_invalid_graph(self):
        """Test extracting config with invalid graph data."""
        workflow = Mock(spec=Workflow)
        workflow.graph_dict = None

        with pytest.raises(ScheduleConfigError, match="Workflow graph is empty"):
            ScheduleService.extract_schedule_config(workflow)


class TestScheduleWithTimezone(unittest.TestCase):
    """Test cases for schedule with timezone handling."""

    def test_visual_schedule_with_timezone_integration(self):
        """Test complete flow: visual config → cron → execution in different timezones.

        This test verifies that when a user in Shanghai sets a schedule for 10:30 AM,
        it runs at 10:30 AM Shanghai time, not 10:30 AM UTC.
        """
        # User in Shanghai wants to run a task at 10:30 AM local time
        visual_config = VisualConfig(
            time="10:30 AM",  # This is Shanghai time
            monthly_days=[1],
        )

        # Convert to cron expression
        cron_expr = ScheduleService.visual_to_cron("monthly", visual_config)
        assert cron_expr is not None

        assert cron_expr == "30 10 1 * *"  # Direct conversion

        # Now test execution with Shanghai timezone
        shanghai_tz = "Asia/Shanghai"
        # Base time: 2025-01-01 00:00:00 UTC (08:00:00 Shanghai)
        base_time = datetime(2025, 1, 1, 0, 0, 0, tzinfo=UTC)

        next_run = calculate_next_run_at(cron_expr, shanghai_tz, base_time)

        assert next_run is not None

        # Should run at 10:30 AM Shanghai time on Jan 1
        # 10:30 AM Shanghai = 02:30 AM UTC (Shanghai is UTC+8)
        assert next_run.year == 2025
        assert next_run.month == 1
        assert next_run.day == 1
        assert next_run.hour == 2  # 02:30 UTC
        assert next_run.minute == 30

    def test_visual_schedule_different_timezones_same_local_time(self):
        """Test that same visual config in different timezones runs at different UTC times.

        This verifies that a schedule set for "9:00 AM" runs at 9 AM local time
        regardless of the timezone.
        """
        visual_config = VisualConfig(
            time="9:00 AM",
            weekdays=["mon"],
        )

        cron_expr = ScheduleService.visual_to_cron("weekly", visual_config)
        assert cron_expr is not None
        assert cron_expr == "0 9 * * 1"

        # Base time: Sunday 2025-01-05 12:00:00 UTC
        base_time = datetime(2025, 1, 5, 12, 0, 0, tzinfo=UTC)

        # Test New York (UTC-5 in January)
        ny_next = calculate_next_run_at(cron_expr, "America/New_York", base_time)
        assert ny_next is not None
        # Monday 9 AM EST = Monday 14:00 UTC
        assert ny_next.day == 6
        assert ny_next.hour == 14  # 9 AM EST = 2 PM UTC

        # Test Tokyo (UTC+9)
        tokyo_next = calculate_next_run_at(cron_expr, "Asia/Tokyo", base_time)
        assert tokyo_next is not None
        # Monday 9 AM JST = Monday 00:00 UTC
        assert tokyo_next.day == 6
        assert tokyo_next.hour == 0  # 9 AM JST = 0 AM UTC

    def test_visual_schedule_daily_across_dst_change(self):
        """Test that daily schedules adjust correctly during DST changes.

        A schedule set for "10:00 AM" should always run at 10 AM local time,
        even when DST changes.
        """
        visual_config = VisualConfig(
            time="10:00 AM",
        )

        cron_expr = ScheduleService.visual_to_cron("daily", visual_config)
        assert cron_expr is not None

        assert cron_expr == "0 10 * * *"

        # Test before DST (EST - UTC-5)
        winter_base = datetime(2025, 2, 1, 0, 0, 0, tzinfo=UTC)
        winter_next = calculate_next_run_at(cron_expr, "America/New_York", winter_base)
        assert winter_next is not None
        # 10 AM EST = 15:00 UTC
        assert winter_next.hour == 15

        # Test during DST (EDT - UTC-4)
        summer_base = datetime(2025, 6, 1, 0, 0, 0, tzinfo=UTC)
        summer_next = calculate_next_run_at(cron_expr, "America/New_York", summer_base)
        assert summer_next is not None
        # 10 AM EDT = 14:00 UTC
        assert summer_next.hour == 14


def _workflow(**kwargs: Any) -> Workflow:
    graph_dict = kwargs.pop("graph_dict", {})
    workflow = Workflow.new(
        tenant_id="tenant-1",
        app_id="app-1",
        type=WorkflowType.WORKFLOW,
        version="draft",
        graph=json.dumps(graph_dict),
        features="{}",
        created_by="account-1",
        environment_variables=[],
        conversation_variables=[],
        rag_pipeline_variables=[],
    )
    for key, value in kwargs.items():
        setattr(workflow, key, value)
    return workflow


def test_to_schedule_config_should_build_from_cron_mode() -> None:
    # Arrange
    node_config: dict[str, Any] = {
        "id": "node-1",
        "data": {
            "mode": "cron",
            "cron_expression": "0 12 * * *",
            "timezone": "Asia/Kolkata",
        },
    }

    # Act
    result = ScheduleService.to_schedule_config(node_config=node_config)

    # Assert
    assert result.node_id == "node-1"
    assert result.cron_expression == "0 12 * * *"
    assert result.timezone == "Asia/Kolkata"


def test_to_schedule_config_should_raise_for_cron_mode_without_expression() -> None:
    # Arrange
    node_config = {"id": "node-1", "data": {"mode": "cron", "cron_expression": ""}}

    # Act / Assert
    with pytest.raises(ScheduleConfigError, match="Cron expression is required for cron mode"):
        ScheduleService.to_schedule_config(node_config=node_config)


def test_to_schedule_config_should_build_from_visual_mode(monkeypatch: pytest.MonkeyPatch) -> None:
    # Arrange
    node_config = {
        "id": "node-1",
        "data": {
            "mode": "visual",
            "frequency": "daily",
            "visual_config": {"time": "9:30 AM"},
            "timezone": "UTC",
        },
    }
    monkeypatch.setattr(ScheduleService, "visual_to_cron", MagicMock(return_value="30 9 * * *"))

    # Act
    result = ScheduleService.to_schedule_config(node_config=node_config)

    # Assert
    assert result.cron_expression == "30 9 * * *"


def test_to_schedule_config_should_raise_for_invalid_mode() -> None:
    # Arrange
    node_config = {"id": "node-1", "data": {"mode": "manual"}}

    # Act / Assert
    with pytest.raises(ScheduleConfigError, match="Invalid schedule mode: manual"):
        ScheduleService.to_schedule_config(node_config=node_config)


def test_extract_schedule_config_should_raise_when_graph_is_empty() -> None:
    # Arrange
    workflow = _workflow(graph_dict={})

    # Act / Assert
    with pytest.raises(ScheduleConfigError, match="Workflow graph is empty"):
        ScheduleService.extract_schedule_config(workflow=workflow)


def test_extract_schedule_config_should_raise_when_mode_invalid() -> None:
    # Arrange
    workflow = _workflow(
        graph_dict={
            "nodes": [
                {
                    "id": "schedule-1",
                    "data": {
                        "type": TRIGGER_SCHEDULE_NODE_TYPE,
                        "mode": "invalid",
                    },
                }
            ]
        }
    )

    # Act / Assert
    with pytest.raises(ScheduleConfigError, match="Invalid schedule mode: invalid"):
        ScheduleService.extract_schedule_config(workflow=workflow)


if __name__ == "__main__":
    unittest.main()