"""Tests for the Command pattern — Create, Update, Delete, Merge contact commands.

Tests cover:
- Permission checks (viewer denied, admin allowed)
- Business logic execution
- Audit log entry creation
- Outbox event enqueuing
- State machine validation
"""

from __future__ import annotations

import pytest
import pytest_asyncio
import uuid as uuid_mod

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.commands.base import CommandResult
from app.commands.contact_commands import (
    CreateContactCommand,
    UpdateContactCommand,
    DeleteContactCommand,
    MergeContactsCommand,
)
from app.core.state_machine import (
    StateMachine,
    StateMachineError,
    contact_state_machine,
    workflow_state_machine,
)
from app.models.audit import AuditLog
from app.models.contact import Contact
from app.models.outbox import EventOutbox

from tests.conftest import ORIGIN_HEADER, login_client, seed_tenant_and_users


# ── State Machine Unit Tests ──


class TestStateMachine:
    """Unit tests for the StateMachine class."""

    def test_can_transition_allowed(self):
        """Allowed transitions return True."""
        assert contact_state_machine.can_transition("lead", "qualified") is True
        assert contact_state_machine.can_transition("qualified", "customer") is True
        assert contact_state_machine.can_transition("customer", "inactive") is True
        assert contact_state_machine.can_transition("inactive", "lead") is True

    def test_can_transition_disallowed(self):
        """Disallowed transitions return False."""
        assert contact_state_machine.can_transition("customer", "lead") is False
        assert contact_state_machine.can_transition("inactive", "customer") is False

    def test_transition_success(self):
        """Valid transition returns the new state."""
        assert contact_state_machine.transition("lead", "qualified") == "qualified"
        assert workflow_state_machine.transition("active", "paused") == "paused"

    def test_transition_invalid_raises(self):
        """Invalid transition raises StateMachineError."""
        with pytest.raises(StateMachineError, match="Invalid state transition"):
            contact_state_machine.transition("customer", "lead")

    def test_transition_unknown_state_raises(self):
        """Transition from unknown state raises StateMachineError."""
        with pytest.raises(StateMachineError, match="Invalid state transition"):
            contact_state_machine.transition("nonexistent", "lead")

    def test_workflow_state_machine_transitions(self):
        """Workflow state machine has correct transitions."""
        assert workflow_state_machine.can_transition("draft", "active") is True
        assert workflow_state_machine.can_transition("active", "paused") is True
        assert workflow_state_machine.can_transition("paused", "active") is True
        assert workflow_state_machine.can_transition("active", "completed") is True
        assert workflow_state_machine.can_transition("active", "cancelled") is True
        assert workflow_state_machine.can_transition("paused", "cancelled") is True
        assert workflow_state_machine.can_transition("draft", "cancelled") is True
        assert workflow_state_machine.can_transition("completed", "active") is False
        assert workflow_state_machine.can_transition("cancelled", "active") is False

    def test_custom_state_machine(self):
        """Custom state machine with own transitions."""
        sm = StateMachine({"a": ["b"], "b": ["c"], "c": []})
        assert sm.can_transition("a", "b") is True
        assert sm.can_transition("b", "c") is True
        assert sm.can_transition("c", "a") is False
        assert sm.transition("a", "b") == "b"
        with pytest.raises(StateMachineError):
            sm.transition("c", "a")


# ── CommandResult Tests ──


class TestCommandResult:
    """Unit tests for CommandResult."""

    def test_ok_result(self):
        """ok() creates a successful result."""
        result = CommandResult.ok(data={"id": "123"})
        assert result.success is True
        assert result.data == {"id": "123"}
        assert result.error is None
        assert result.events == []

    def test_ok_with_events(self):
        """ok() with events creates a successful result with events."""
        events = [{"event": "contact.created"}]
        result = CommandResult.ok(data={}, events=events)
        assert result.events == events

    def test_fail_result(self):
        """fail() creates a failed result."""
        result = CommandResult.fail("Something went wrong")
        assert result.success is False
        assert result.data is None
        assert result.error == "Something went wrong"
        assert result.events == []


# ── CreateContactCommand Tests ──


@pytest.mark.asyncio
class TestCreateContactCommand:
    """Tests for CreateContactCommand."""

    async def test_create_contact_admin_success(
        self, client, db_session: AsyncSession, redis_client
    ):
        """Admin can create a contact, audit log is created, outbox event enqueued."""
        seed = await seed_tenant_and_users(db_session)
        await login_client(client, "admin@tenanta.com")

        # Use command directly with db_session and redis_client
        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        cmd = CreateContactCommand(data={
            "type": "company",
            "name": "Test Company",
            "email_1": "test@example.com",
        })
        result = await cmd.execute(db_session, redis_client, current_user)

        assert result.success is True
        assert result.data is not None
        assert result.data["name"] == "Test Company"
        assert result.data["displayname"] == "Test Company"
        assert len(result.events) >= 1
        assert result.events[0]["event"] == "contact.created"

        # Verify audit log was created
        await db_session.flush()
        audit_q = select(AuditLog).where(
            AuditLog.entity_type == "contact",
            AuditLog.action == "create",
            AuditLog.user_id == seed["admin_a"].id,
        )
        audit_result = await db_session.execute(audit_q)
        audit_entries = audit_result.scalars().all()
        assert len(audit_entries) >= 1
        assert audit_entries[0].entity_id == uuid_mod.UUID(result.data["id"])

        # Verify outbox event was enqueued
        outbox_q = select(EventOutbox).where(
            EventOutbox.event_name == "contact.created"
        )
        outbox_result = await db_session.execute(outbox_q)
        outbox_entries = outbox_result.scalars().all()
        assert len(outbox_entries) >= 1

    async def test_create_contact_viewer_denied(
        self, db_session: AsyncSession, redis_client
    ):
        """Viewer cannot create a contact (permission denied)."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["viewer_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "viewer",
            "is_system_admin": False,
            "permissions": ["contacts:read"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        cmd = CreateContactCommand(data={
            "type": "company",
            "name": "Denied Company",
        })
        result = await cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "Permission denied" in result.error

    async def test_create_contact_with_invalid_status(
        self, db_session: AsyncSession, redis_client
    ):
        """Creating a contact with invalid status fails."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        cmd = CreateContactCommand(data={
            "type": "company",
            "name": "Bad Status Corp",
            "status": "nonexistent",
        })
        result = await cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "Invalid contact status" in result.error


# ── UpdateContactCommand Tests ──


@pytest.mark.asyncio
class TestUpdateContactCommand:
    """Tests for UpdateContactCommand."""

    async def test_update_contact_admin_success(
        self, db_session: AsyncSession, redis_client
    ):
        """Admin can update a contact, audit log created, outbox event enqueued."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        # First create a contact
        create_cmd = CreateContactCommand(data={
            "type": "company",
            "name": "Original Name",
        })
        create_result = await create_cmd.execute(db_session, redis_client, current_user)
        assert create_result.success is True
        contact_id = create_result.data["id"]

        # Update the contact
        update_cmd = UpdateContactCommand(
            contact_id=contact_id,
            data={"name": "Updated Name", "email_1": "updated@example.com"},
        )
        update_result = await update_cmd.execute(db_session, redis_client, current_user)

        assert update_result.success is True
        assert update_result.data["name"] == "Updated Name"
        assert update_result.data["email_1"] == "updated@example.com"
        assert len(update_result.events) >= 1
        assert update_result.events[0]["event"] == "contact.updated"

        # Verify audit log
        await db_session.flush()
        audit_q = select(AuditLog).where(
            AuditLog.entity_type == "contact",
            AuditLog.action == "update",
            AuditLog.entity_id == uuid_mod.UUID(contact_id),
        )
        audit_result = await db_session.execute(audit_q)
        audit_entries = audit_result.scalars().all()
        assert len(audit_entries) >= 1

    async def test_update_contact_not_found(
        self, db_session: AsyncSession, redis_client
    ):
        """Updating a non-existent contact fails gracefully."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        random_id = str(uuid_mod.uuid4())
        update_cmd = UpdateContactCommand(
            contact_id=random_id,
            data={"name": "New Name"},
        )
        result = await update_cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "not found" in result.error.lower()

    async def test_update_contact_viewer_denied(
        self, db_session: AsyncSession, redis_client
    ):
        """Viewer cannot update a contact."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["viewer_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "viewer",
            "is_system_admin": False,
            "permissions": ["contacts:read"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        cmd = UpdateContactCommand(
            contact_id=str(seed["company_a"].id),
            data={"name": "Hacked"},
        )
        result = await cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "Permission denied" in result.error


# ── DeleteContactCommand Tests ──


@pytest.mark.asyncio
class TestDeleteContactCommand:
    """Tests for DeleteContactCommand."""

    async def test_soft_delete_contact_admin_success(
        self, db_session: AsyncSession, redis_client
    ):
        """Admin can soft-delete a contact."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        # Create a contact to delete
        create_cmd = CreateContactCommand(data={
            "type": "company",
            "name": "To Delete",
        })
        create_result = await create_cmd.execute(db_session, redis_client, current_user)
        assert create_result.success is True
        contact_id = create_result.data["id"]

        # Soft-delete it
        delete_cmd = DeleteContactCommand(contact_id=contact_id, hard=False)
        delete_result = await delete_cmd.execute(db_session, redis_client, current_user)

        assert delete_result.success is True
        assert delete_result.data is None
        assert len(delete_result.events) >= 1
        assert delete_result.events[0]["event"] == "contact.deleted"

        # Verify audit log
        await db_session.flush()
        audit_q = select(AuditLog).where(
            AuditLog.entity_type == "contact",
            AuditLog.action == "delete",
            AuditLog.entity_id == uuid_mod.UUID(contact_id),
        )
        audit_result = await db_session.execute(audit_q)
        audit_entries = audit_result.scalars().all()
        assert len(audit_entries) >= 1

    async def test_hard_delete_contact_admin_success(
        self, db_session: AsyncSession, redis_client
    ):
        """Admin can hard-delete a contact."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        # Create a contact to hard-delete
        create_cmd = CreateContactCommand(data={
            "type": "company",
            "name": "Hard Delete Me",
        })
        create_result = await create_cmd.execute(db_session, redis_client, current_user)
        assert create_result.success is True
        contact_id = create_result.data["id"]

        # Hard-delete it
        delete_cmd = DeleteContactCommand(contact_id=contact_id, hard=True)
        delete_result = await delete_cmd.execute(db_session, redis_client, current_user)

        assert delete_result.success is True
        assert len(delete_result.events) >= 1
        assert delete_result.events[0]["event"] == "contact.hard_deleted"

    async def test_delete_contact_not_found(
        self, db_session: AsyncSession, redis_client
    ):
        """Deleting a non-existent contact fails gracefully."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        random_id = str(uuid_mod.uuid4())
        delete_cmd = DeleteContactCommand(contact_id=random_id)
        result = await delete_cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "not found" in result.error.lower()

    async def test_delete_contact_viewer_denied(
        self, db_session: AsyncSession, redis_client
    ):
        """Viewer cannot delete a contact."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["viewer_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "viewer",
            "is_system_admin": False,
            "permissions": ["contacts:read"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        cmd = DeleteContactCommand(contact_id=str(seed["company_a"].id))
        result = await cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "Permission denied" in result.error


# ── MergeContactsCommand Tests ──


@pytest.mark.asyncio
class TestMergeContactsCommand:
    """Tests for MergeContactsCommand."""

    async def test_merge_contacts_admin_success(
        self, db_session: AsyncSession, redis_client
    ):
        """Admin can merge two contacts, audit log created, outbox event enqueued."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        # Create two contacts to merge
        create_cmd1 = CreateContactCommand(data={
            "type": "company",
            "name": "Source Company",
            "email_1": "source@example.com",
        })
        result1 = await create_cmd1.execute(db_session, redis_client, current_user)
        assert result1.success is True
        source_id = result1.data["id"]

        create_cmd2 = CreateContactCommand(data={
            "type": "company",
            "name": "Target Company",
            "email_1": "target@example.com",
        })
        result2 = await create_cmd2.execute(db_session, redis_client, current_user)
        assert result2.success is True
        target_id = result2.data["id"]

        # Merge source → target
        merge_cmd = MergeContactsCommand(
            source_contact_id=source_id,
            target_contact_id=target_id,
            note="Duplicate detected",
        )
        merge_result = await merge_cmd.execute(db_session, redis_client, current_user)

        assert merge_result.success is True
        assert merge_result.data is not None
        assert "history" in merge_result.data
        assert merge_result.data["history"]["source_id"] == source_id
        assert merge_result.data["history"]["target_id"] == target_id
        assert len(merge_result.events) >= 1
        assert merge_result.events[0]["event"] == "contact.merged"

        # Verify audit log
        await db_session.flush()
        audit_q = select(AuditLog).where(
            AuditLog.entity_type == "contact",
            AuditLog.action == "merge",
            AuditLog.entity_id == uuid_mod.UUID(target_id),
        )
        audit_result = await db_session.execute(audit_q)
        audit_entries = audit_result.scalars().all()
        assert len(audit_entries) >= 1

    async def test_merge_same_contact_fails(
        self, db_session: AsyncSession, redis_client
    ):
        """Merging a contact with itself fails."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        # Create a contact
        create_cmd = CreateContactCommand(data={
            "type": "company",
            "name": "Solo Company",
        })
        create_result = await create_cmd.execute(db_session, redis_client, current_user)
        assert create_result.success is True
        contact_id = create_result.data["id"]

        # Try to merge with itself
        merge_cmd = MergeContactsCommand(
            source_contact_id=contact_id,
            target_contact_id=contact_id,
        )
        result = await merge_cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "must be different" in result.error

    async def test_merge_contacts_viewer_denied(
        self, db_session: AsyncSession, redis_client
    ):
        """Viewer cannot merge contacts."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["viewer_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "viewer",
            "is_system_admin": False,
            "permissions": ["contacts:read"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        merge_cmd = MergeContactsCommand(
            source_contact_id=str(seed["company_a"].id),
            target_contact_id=str(seed["company_a"].id),
        )
        result = await merge_cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "Permission denied" in result.error

    async def test_merge_contact_not_found(
        self, db_session: AsyncSession, redis_client
    ):
        """Merging with a non-existent contact fails."""
        seed = await seed_tenant_and_users(db_session)

        current_user = {
            "user_id": str(seed["admin_a"].id),
            "tenant_id": str(seed["tenant_a"].id),
            "role": "admin",
            "is_system_admin": True,
            "permissions": ["*: *"],
            "denied_permissions": [],
            "field_permissions": {},
        }

        random_id = str(uuid_mod.uuid4())
        merge_cmd = MergeContactsCommand(
            source_contact_id=random_id,
            target_contact_id=str(seed["company_a"].id),
        )
        result = await merge_cmd.execute(db_session, redis_client, current_user)

        assert result.success is False
        assert "not found" in result.error.lower()