"""
Deep behavioral tests for state machine patterns.
Tests state transitions, guards, actions,
and workflow state management logic.
"""

from datetime import datetime, timezone


# --- Basic state machine patterns ---


class TestBasicStateMachine:
    """Tests for basic state machine patterns."""

    def _create_state_machine(self, initial_state, transitions):
        """Create a simple state machine."""
        return {
            "current_state": initial_state,
            "transitions": transitions,
            "history": [initial_state],
        }

    def _can_transition(self, machine, event):
        """Check if transition is allowed."""
        current = machine["current_state"]
        transitions = machine["transitions"]
        if current not in transitions:
            return False
        return event in transitions[current]

    def _transition(self, machine, event):
        """Perform state transition."""
        if not self._can_transition(machine, event):
            return False
        current = machine["current_state"]
        new_state = machine["transitions"][current][event]
        machine["current_state"] = new_state
        machine["history"].append(new_state)
        return True

    def test_initial_state(self):
        machine = self._create_state_machine("idle", {})
        assert machine["current_state"] == "idle"

    def test_can_transition(self):
        transitions = {"idle": {"start": "running"}}
        machine = self._create_state_machine("idle", transitions)
        assert self._can_transition(machine, "start") is True

    def test_cannot_transition_invalid_event(self):
        transitions = {"idle": {"start": "running"}}
        machine = self._create_state_machine("idle", transitions)
        assert self._can_transition(machine, "stop") is False

    def test_transition_changes_state(self):
        transitions = {"idle": {"start": "running"}}
        machine = self._create_state_machine("idle", transitions)
        self._transition(machine, "start")
        assert machine["current_state"] == "running"

    def test_history_tracks_states(self):
        transitions = {
            "idle": {"start": "running"},
            "running": {"stop": "stopped"},
        }
        machine = self._create_state_machine("idle", transitions)
        self._transition(machine, "start")
        self._transition(machine, "stop")
        assert machine["history"] == ["idle", "running", "stopped"]


# --- Subscription state patterns ---


class TestSubscriptionStates:
    """Tests for subscription state patterns."""

    def _get_subscription_transitions(self):
        """Get subscription state transitions."""
        return {
            "pending": {"activate": "active", "cancel": "cancelled"},
            "active": {
                "pause": "paused",
                "cancel": "cancelled",
                "expire": "expired",
            },
            "paused": {"resume": "active", "cancel": "cancelled"},
            "expired": {"renew": "active"},
            "cancelled": {},  # Terminal state
        }

    def _is_terminal_state(self, state):
        """Check if state is terminal."""
        transitions = self._get_subscription_transitions()
        return state not in transitions or len(transitions.get(state, {})) == 0

    def _get_available_actions(self, state):
        """Get available actions for state."""
        transitions = self._get_subscription_transitions()
        return list(transitions.get(state, {}).keys())

    def test_pending_can_activate(self):
        actions = self._get_available_actions("pending")
        assert "activate" in actions

    def test_active_can_pause(self):
        actions = self._get_available_actions("active")
        assert "pause" in actions

    def test_cancelled_is_terminal(self):
        assert self._is_terminal_state("cancelled") is True

    def test_active_not_terminal(self):
        assert self._is_terminal_state("active") is False


# --- Card state patterns ---


class TestCardStates:
    """Tests for news card state patterns."""

    def _get_card_transitions(self):
        """Get card state transitions."""
        return {
            "draft": {"publish": "published", "archive": "archived"},
            "published": {"archive": "archived", "feature": "featured"},
            "featured": {"unfeature": "published", "archive": "archived"},
            "archived": {"restore": "published"},
        }

    def _validate_card_state(self, state):
        """Validate card state."""
        valid_states = ["draft", "published", "featured", "archived"]
        return state in valid_states

    def test_draft_can_publish(self):
        transitions = self._get_card_transitions()
        assert "publish" in transitions["draft"]

    def test_published_can_feature(self):
        transitions = self._get_card_transitions()
        assert "feature" in transitions["published"]

    def test_valid_state(self):
        assert self._validate_card_state("published") is True

    def test_invalid_state(self):
        assert self._validate_card_state("unknown") is False


# --- Research state patterns ---


class TestResearchStates:
    """Tests for research task state patterns."""

    def _get_research_transitions(self):
        """Get research state transitions."""
        return {
            "queued": {"start": "running", "cancel": "cancelled"},
            "running": {
                "complete": "completed",
                "fail": "failed",
                "cancel": "cancelled",
            },
            "completed": {"archive": "archived"},
            "failed": {"retry": "queued", "archive": "archived"},
            "cancelled": {"archive": "archived"},
            "archived": {},
        }

    def _can_retry(self, state):
        """Check if research can be retried."""
        return state == "failed"

    def _is_active(self, state):
        """Check if research is active."""
        return state in ["queued", "running"]

    def _is_finished(self, state):
        """Check if research is finished."""
        return state in ["completed", "failed", "cancelled", "archived"]

    def test_failed_can_retry(self):
        assert self._can_retry("failed") is True

    def test_completed_cannot_retry(self):
        assert self._can_retry("completed") is False

    def test_running_is_active(self):
        assert self._is_active("running") is True

    def test_completed_is_finished(self):
        assert self._is_finished("completed") is True

    def test_running_not_finished(self):
        assert self._is_finished("running") is False


# --- Guard condition patterns ---


class TestGuardConditions:
    """Tests for state transition guard conditions."""

    def _check_guard(self, guard_name, context):
        """Check if guard condition passes."""
        guards = {
            "is_authenticated": lambda ctx: ctx.get("user_id") is not None,
            "has_permission": lambda ctx: (
                ctx.get("role") in ["admin", "editor"]
            ),
            "is_valid": lambda ctx: ctx.get("is_valid", False),
            "not_expired": lambda ctx: (
                ctx.get("expires_at", datetime.max) > datetime.now(timezone.utc)
            ),
        }
        guard_func = guards.get(guard_name)
        if not guard_func:
            return True
        return guard_func(context)

    def _transition_with_guard(self, machine, event, guard, context):
        """Transition only if guard passes."""
        if not self._check_guard(guard, context):
            return False, "Guard failed"
        # Perform transition logic would go here
        return True, "Success"

    def test_authenticated_guard_passes(self):
        context = {"user_id": "123"}
        assert self._check_guard("is_authenticated", context) is True

    def test_authenticated_guard_fails(self):
        context = {}
        assert self._check_guard("is_authenticated", context) is False

    def test_permission_guard_admin(self):
        context = {"role": "admin"}
        assert self._check_guard("has_permission", context) is True

    def test_permission_guard_user_fails(self):
        context = {"role": "user"}
        assert self._check_guard("has_permission", context) is False


# --- Action patterns ---


class TestStateActions:
    """Tests for state transition actions."""

    def _execute_entry_action(self, state, context):
        """Execute action when entering state."""
        actions = {
            "running": lambda ctx: ctx.update(
                {"started_at": datetime.now(timezone.utc)}
            ),
            "completed": lambda ctx: ctx.update(
                {"completed_at": datetime.now(timezone.utc)}
            ),
            "paused": lambda ctx: ctx.update(
                {"paused_at": datetime.now(timezone.utc)}
            ),
        }
        action = actions.get(state)
        if action:
            action(context)
        return context

    def _execute_exit_action(self, state, context):
        """Execute action when exiting state."""
        actions = {
            "running": lambda ctx: ctx.update(
                {"duration": self._calculate_duration(ctx)}
            ),
        }
        action = actions.get(state)
        if action:
            action(context)
        return context

    def _calculate_duration(self, context):
        """Calculate duration from started_at."""
        started = context.get("started_at")
        if started:
            return (datetime.now(timezone.utc) - started).total_seconds()
        return 0

    def test_entry_action_sets_timestamp(self):
        context = {}
        self._execute_entry_action("running", context)
        assert "started_at" in context

    def test_completed_entry_action(self):
        context = {}
        self._execute_entry_action("completed", context)
        assert "completed_at" in context


# --- Workflow state patterns ---


class TestWorkflowStates:
    """Tests for multi-step workflow states."""

    def _create_workflow(self, steps):
        """Create a workflow with steps."""
        return {
            "steps": steps,
            "current_step": 0,
            "completed_steps": [],
            "status": "pending",
        }

    def _advance_workflow(self, workflow):
        """Advance to next step."""
        if workflow["current_step"] >= len(workflow["steps"]):
            return False
        current = workflow["steps"][workflow["current_step"]]
        workflow["completed_steps"].append(current)
        workflow["current_step"] += 1
        if workflow["current_step"] >= len(workflow["steps"]):
            workflow["status"] = "completed"
        else:
            workflow["status"] = "in_progress"
        return True

    def _get_current_step(self, workflow):
        """Get current step name."""
        if workflow["current_step"] >= len(workflow["steps"]):
            return None
        return workflow["steps"][workflow["current_step"]]

    def _get_progress(self, workflow):
        """Get workflow progress percentage."""
        if not workflow["steps"]:
            return 100
        return (workflow["current_step"] / len(workflow["steps"])) * 100

    def test_workflow_starts_pending(self):
        workflow = self._create_workflow(["step1", "step2"])
        assert workflow["status"] == "pending"

    def test_advance_changes_step(self):
        workflow = self._create_workflow(["step1", "step2"])
        self._advance_workflow(workflow)
        assert workflow["current_step"] == 1

    def test_advance_completes_workflow(self):
        workflow = self._create_workflow(["step1"])
        self._advance_workflow(workflow)
        assert workflow["status"] == "completed"

    def test_progress_calculation(self):
        workflow = self._create_workflow(["a", "b", "c", "d"])
        self._advance_workflow(workflow)
        self._advance_workflow(workflow)
        assert self._get_progress(workflow) == 50


# --- Hierarchical state patterns ---


class TestHierarchicalStates:
    """Tests for hierarchical state machine patterns."""

    def _get_parent_state(self, state, hierarchy):
        """Get parent state from hierarchy."""
        for parent, children in hierarchy.items():
            if state in children:
                return parent
        return None

    def _get_child_states(self, parent, hierarchy):
        """Get child states of a parent."""
        return hierarchy.get(parent, [])

    def _is_in_state(self, current, target, hierarchy):
        """Check if current state is or is within target state."""
        if current == target:
            return True
        parent = self._get_parent_state(current, hierarchy)
        if parent:
            return self._is_in_state(parent, target, hierarchy)
        return False

    def test_get_parent_state(self):
        hierarchy = {"active": ["running", "paused"]}
        parent = self._get_parent_state("running", hierarchy)
        assert parent == "active"

    def test_get_child_states(self):
        hierarchy = {"active": ["running", "paused"]}
        children = self._get_child_states("active", hierarchy)
        assert "running" in children

    def test_is_in_nested_state(self):
        hierarchy = {"active": ["running", "paused"]}
        assert self._is_in_state("running", "active", hierarchy) is True

    def test_not_in_unrelated_state(self):
        hierarchy = {"active": ["running", "paused"]}
        assert self._is_in_state("running", "idle", hierarchy) is False


# --- Parallel state patterns ---


class TestParallelStates:
    """Tests for parallel/orthogonal state patterns."""

    def _create_parallel_machine(self, regions):
        """Create parallel state machine with multiple regions."""
        return {
            "regions": {
                name: {"state": initial} for name, initial in regions.items()
            },
        }

    def _get_region_state(self, machine, region):
        """Get state of a specific region."""
        return machine["regions"].get(region, {}).get("state")

    def _transition_region(self, machine, region, new_state):
        """Transition a specific region."""
        if region in machine["regions"]:
            machine["regions"][region]["state"] = new_state
            return True
        return False

    def _get_combined_state(self, machine):
        """Get combined state from all regions."""
        return {name: r["state"] for name, r in machine["regions"].items()}

    def test_parallel_initial_states(self):
        machine = self._create_parallel_machine(
            {"audio": "muted", "video": "off"}
        )
        assert self._get_region_state(machine, "audio") == "muted"
        assert self._get_region_state(machine, "video") == "off"

    def test_transition_single_region(self):
        machine = self._create_parallel_machine(
            {"audio": "muted", "video": "off"}
        )
        self._transition_region(machine, "audio", "playing")
        assert self._get_region_state(machine, "audio") == "playing"
        assert self._get_region_state(machine, "video") == "off"

    def test_combined_state(self):
        machine = self._create_parallel_machine({"a": "s1", "b": "s2"})
        combined = self._get_combined_state(machine)
        assert combined == {"a": "s1", "b": "s2"}


# --- State persistence patterns ---


class TestStatePersistence:
    """Tests for state persistence patterns."""

    def _serialize_state(self, machine):
        """Serialize state machine to dict."""
        return {
            "current_state": machine["current_state"],
            "history": machine.get("history", []),
            "context": machine.get("context", {}),
        }

    def _deserialize_state(self, data, transitions):
        """Deserialize state machine from dict."""
        return {
            "current_state": data["current_state"],
            "transitions": transitions,
            "history": data.get("history", [data["current_state"]]),
            "context": data.get("context", {}),
        }

    def test_serialize_preserves_state(self):
        machine = {
            "current_state": "running",
            "history": ["idle", "running"],
            "context": {"user": "test"},
        }
        serialized = self._serialize_state(machine)
        assert serialized["current_state"] == "running"
        assert serialized["history"] == ["idle", "running"]

    def test_deserialize_restores_state(self):
        data = {
            "current_state": "paused",
            "history": ["idle", "running", "paused"],
        }
        transitions = {"paused": {"resume": "running"}}
        machine = self._deserialize_state(data, transitions)
        assert machine["current_state"] == "paused"
        assert machine["transitions"] == transitions


# --- State validation patterns ---


class TestStateValidation:
    """Tests for state validation patterns."""

    def _validate_state(self, state, valid_states):
        """Validate state is in valid states."""
        return state in valid_states

    def _validate_transition(self, from_state, to_state, transitions):
        """Validate transition is allowed."""
        if from_state not in transitions:
            return False
        allowed = transitions[from_state].values()
        return to_state in allowed

    def _validate_machine(self, machine):
        """Validate state machine integrity."""
        errors = []
        current = machine.get("current_state")
        transitions = machine.get("transitions", {})
        # Check current state is valid
        all_states = set(transitions.keys())
        for targets in transitions.values():
            all_states.update(targets.values())
        if current not in all_states:
            errors.append(f"Invalid current state: {current}")
        return len(errors) == 0, errors

    def test_valid_state(self):
        assert (
            self._validate_state("active", ["idle", "active", "done"]) is True
        )

    def test_invalid_state(self):
        assert self._validate_state("unknown", ["idle", "active"]) is False

    def test_valid_transition(self):
        transitions = {"idle": {"start": "running"}}
        assert self._validate_transition("idle", "running", transitions) is True

    def test_invalid_transition(self):
        transitions = {"idle": {"start": "running"}}
        assert (
            self._validate_transition("idle", "stopped", transitions) is False
        )


# --- State timeout patterns ---


class TestStateTimeouts:
    """Tests for state timeout patterns."""

    def _check_timeout(self, entered_at, timeout_seconds):
        """Check if state has timed out."""
        if not entered_at:
            return False
        elapsed = (datetime.now(timezone.utc) - entered_at).total_seconds()
        return elapsed > timeout_seconds

    def _get_timeout_for_state(self, state):
        """Get timeout configuration for state."""
        timeouts = {
            "pending": 3600,  # 1 hour
            "processing": 300,  # 5 minutes
            "waiting": 86400,  # 24 hours
        }
        return timeouts.get(state)

    def _should_auto_transition(self, state, entered_at):
        """Check if state should auto-transition due to timeout."""
        timeout = self._get_timeout_for_state(state)
        if not timeout:
            return False
        return self._check_timeout(entered_at, timeout)

    def test_no_timeout_fresh_state(self):
        entered = datetime.now(timezone.utc)
        assert self._check_timeout(entered, 60) is False

    def test_timeout_expired(self):
        from datetime import timedelta

        entered = datetime.now(timezone.utc) - timedelta(seconds=120)
        assert self._check_timeout(entered, 60) is True

    def test_state_has_timeout(self):
        timeout = self._get_timeout_for_state("pending")
        assert timeout == 3600

    def test_state_no_timeout(self):
        timeout = self._get_timeout_for_state("completed")
        assert timeout is None
