from __future__ import annotations

import tempfile
import unittest
from pathlib import Path
import shutil

from alembic.runtime.migration import MigrationContext
from sqlalchemy import create_engine, inspect, text

from govoplan_core.db.migrations import migrate_database
from dataclasses import replace

from govoplan_workflow_engine.backend.manifest import get_manifest


class WorkflowMigrationTests(unittest.TestCase):
    def test_migration_creates_definition_tables_and_head(self) -> None:
        with tempfile.TemporaryDirectory(
            prefix="govoplan-workflow-engine-migration-"
        ) as directory:
            url = f"sqlite:///{Path(directory) / 'workflow.db'}"
            migrate_database(
                database_url=url,
                enabled_modules=("workflow_engine",),
                manifest_factories=(get_manifest,),
            )
            engine = create_engine(url)
            try:
                with engine.connect() as connection:
                    self.assertIn(
                        "9e6b3f8a2c7d",
                        set(MigrationContext.configure(connection).get_current_heads()),
                    )
                    self.assertEqual(
                        {
                            "workflow_definition_revisions",
                            "workflow_definitions",
                            "workflow_instance_events",
                            "workflow_instance_steps",
                            "workflow_instances",
                            "workflow_triggers",
                            "workflow_trigger_deliveries",
                            "workflow_wait_states",
                        },
                        {
                            name
                            for name in inspect(connection).get_table_names()
                            if name.startswith("workflow_")
                        },
                    )
                    revision_columns = {
                        item["name"]
                        for item in inspect(connection).get_columns(
                            "workflow_definition_revisions"
                        )
                    }
                    self.assertTrue(
                        {
                            "bpmn_xml",
                            "bpmn_hash",
                            "bpmn_adapter_id",
                            "bpmn_adapter_version",
                            "bpmn_runtime_kind",
                            "bpmn_executable",
                            "execution_mode",
                            "view_id",
                            "view_revision_id",
                        }.issubset(revision_columns)
                    )
                    instance_columns = {
                        item["name"]
                        for item in inspect(connection).get_columns(
                            "workflow_instances"
                        )
                    }
                    self.assertIn("start_origin", instance_columns)
                    indexes = {
                        item["name"]: item["column_names"]
                        for item in inspect(connection).get_indexes("workflow_instances")
                    }
                    self.assertEqual(
                        ["tenant_id", "created_at", "id"],
                        indexes["ix_workflow_instances_tenant_created_id"],
                    )
                    self.assertEqual(
                        ["tenant_id", "definition_id", "created_at", "id"],
                        indexes["ix_workflow_instances_tenant_definition_created_id"],
                    )
                    definition_columns = {
                        item["name"]
                        for item in inspect(connection).get_columns(
                            "workflow_definitions"
                        )
                    }
                    self.assertIn(
                        "standard_origin_module_id",
                        definition_columns,
                    )
            finally:
                engine.dispose()

    def test_existing_workflow_migration_head_transfers_without_replay(self) -> None:
        with tempfile.TemporaryDirectory(
            prefix="govoplan-workflow-engine-upgrade-"
        ) as directory:
            url = f"sqlite:///{Path(directory) / 'workflow.db'}"
            engine_manifest = get_manifest()
            assert engine_manifest.migration_spec is not None
            legacy_revisions = Path(directory) / "legacy-revisions"
            legacy_revisions.mkdir()
            current_revisions = Path(
                engine_manifest.migration_spec.script_location or ""
            )
            for path in current_revisions.glob("*.py"):
                if path.name.startswith(
                    (
                        "0b4e7c9a2d6f_",
                        "b2e4f6a8c0d1_",
                        "e4a1f8c2d7b6_",
                        "8d5a2f7c1b4e_",
                        "9e6b3f8a2c7d_",
                    )
                ):
                    continue
                shutil.copy2(path, legacy_revisions / path.name)
            legacy_manifest = replace(
                engine_manifest,
                id="workflow",
                name="Workflow",
                permission_namespace=None,
                migration_spec=replace(
                    engine_manifest.migration_spec,
                    module_id="workflow",
                    script_location=str(legacy_revisions),
                ),
            )
            migrate_database(
                database_url=url,
                enabled_modules=("workflow",),
                manifest_factories=(lambda: legacy_manifest,),
            )
            engine = create_engine(url)
            try:
                first_tables = set(inspect(engine).get_table_names())
                with engine.connect() as connection:
                    self.assertIn(
                        "f1b7d3e5a9c2",
                        set(MigrationContext.configure(connection).get_current_heads()),
                    )
                self.assertNotIn(
                    "standard_origin_module_id",
                    {
                        item["name"]
                        for item in inspect(engine).get_columns("workflow_definitions")
                    },
                )
            finally:
                engine.dispose()

            result = migrate_database(
                database_url=url,
                enabled_modules=("workflow_engine",),
                manifest_factories=(get_manifest,),
            )

            self.assertIn("9e6b3f8a2c7d", result.current_revision or "")
            engine = create_engine(url)
            try:
                upgraded_tables = set(inspect(engine).get_table_names())
                self.assertTrue(first_tables.issubset(upgraded_tables))
                self.assertTrue(
                    {
                        "workflow_triggers",
                        "workflow_trigger_deliveries",
                        "workflow_wait_states",
                    }.issubset(upgraded_tables)
                )
                self.assertIn(
                    "standard_origin_module_id",
                    {
                        item["name"]
                        for item in inspect(engine).get_columns("workflow_definitions")
                    },
                )
            finally:
                engine.dispose()

    def test_repair_revision_adds_columns_missing_from_applied_parent(self) -> None:
        with tempfile.TemporaryDirectory(
            prefix="govoplan-workflow-engine-repair-"
        ) as directory:
            url = f"sqlite:///{Path(directory) / 'workflow.db'}"
            migrate_database(
                database_url=url,
                enabled_modules=("workflow_engine",),
                manifest_factories=(get_manifest,),
            )
            engine = create_engine(url)
            try:
                with engine.begin() as connection:
                    for index_name in (
                        "ix_workflow_instances_tenant_created_id",
                        "ix_workflow_instances_tenant_definition_created_id",
                        "ix_workflow_instance_steps_work_assignment",
                        "ix_workflow_instance_steps_work_due_at",
                        "ix_workflow_instance_steps_work_assignment_id",
                        "ix_workflow_instance_steps_work_assignment_kind",
                    ):
                        connection.execute(text(f"DROP INDEX {index_name}"))
                    for column_name in (
                        "work_due_at",
                        "work_assignment_label",
                        "work_assignment_id",
                        "work_assignment_kind",
                    ):
                        connection.execute(
                            text(
                                "ALTER TABLE workflow_instance_steps "
                                f"DROP COLUMN {column_name}"
                            )
                        )
                    connection.execute(
                        text(
                            "ALTER TABLE workflow_definition_revisions "
                            "DROP COLUMN bpmn_runtime_kind"
                        )
                    )
                    connection.execute(
                        text(
                            "ALTER TABLE workflow_definition_revisions "
                            "DROP COLUMN bpmn_executable"
                        )
                    )
                    connection.execute(
                        text(
                            "UPDATE alembic_version SET version_num = "
                            "'b2e4f6a8c0d1' WHERE version_num = '9e6b3f8a2c7d'"
                        )
                    )
            finally:
                engine.dispose()

            migrate_database(
                database_url=url,
                enabled_modules=("workflow_engine",),
                manifest_factories=(get_manifest,),
            )

            engine = create_engine(url)
            try:
                columns = {
                    item["name"]
                    for item in inspect(engine).get_columns(
                        "workflow_definition_revisions"
                    )
                }
                self.assertIn("bpmn_runtime_kind", columns)
                self.assertIn("bpmn_executable", columns)
                step_columns = {
                    item["name"]
                    for item in inspect(engine).get_columns(
                        "workflow_instance_steps"
                    )
                }
                self.assertTrue(
                    {
                        "work_assignment_kind",
                        "work_assignment_id",
                        "work_assignment_label",
                        "work_due_at",
                    }.issubset(step_columns)
                )
                with engine.connect() as connection:
                    self.assertIn(
                        "9e6b3f8a2c7d",
                        set(MigrationContext.configure(connection).get_current_heads()),
                    )
            finally:
                engine.dispose()


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