from pathlib import Path
from types import SimpleNamespace
from datetime import datetime
import json
import tempfile
import unittest
from unittest.mock import AsyncMock, patch

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

from backend.agent import api
from backend.agent.models import WorkflowDefinition, WorkflowRun
from backend.agent.schemas import WorkflowRunRequest
from backend.agent.workflows.builtins import seed_builtin_workflows
from backend.database import Base
from backend.models import ChatMessage, ChatSession


class WorkflowApiTests(unittest.IsolatedAsyncioTestCase):
    async def asyncSetUp(self):
        self.temp = tempfile.TemporaryDirectory()
        self.engine = create_engine(
            f"sqlite:///{Path(self.temp.name) / 'api.db'}",
            connect_args={"check_same_thread": False},
        )
        Base.metadata.create_all(self.engine)
        self.Session = sessionmaker(bind=self.engine)
        db = self.Session()
        seed_builtin_workflows(db)
        direct = db.query(WorkflowDefinition).filter_by(slug="input-output").one()
        chat = ChatSession(session_id="regenerate-chat")
        db.add(chat)
        db.flush()
        user = ChatMessage(session_pk=chat.id, role="user", content="original")
        db.add(user)
        db.flush()
        assistant = ChatMessage(
            session_pk=chat.id,
            role="assistant",
            content="old answer",
            workflow_id=direct.id,
            workflow_revision_id=direct.current_revision_id,
        )
        db.add(assistant)
        db.flush()
        db.commit()
        self.user_message_id = user.message_id
        self.assistant_message_id = assistant.message_id
        self.direct_workflow_id = direct.id
        self.direct_revision_id = direct.current_revision_id
        db.close()

    async def asyncTearDown(self):
        self.engine.dispose()
        self.temp.cleanup()

    async def test_regeneration_reuses_user_row_and_prunes_old_answer(self):
        started = []
        fake_runtime = SimpleNamespace(start=started.append)
        request = WorkflowRunRequest(
            session_id="regenerate-chat",
            message="edited",
            model="test-model",
            selection_mode="direct",
            workflow_revision_id=self.direct_revision_id,
            regenerate_index=0,
        )
        with patch.object(api, "SessionLocal", self.Session), patch.object(api, "runtime", fake_runtime):
            response = await api.create_workflow_run(request)

        self.assertEqual(started, [response["run_id"]])
        db = self.Session()
        rows = db.query(ChatMessage).order_by(ChatMessage.id.asc()).all()
        self.assertEqual(len(rows), 1)
        self.assertEqual(rows[0].message_id, self.user_message_id)
        self.assertEqual(rows[0].content, "edited")
        run = db.query(WorkflowRun).filter_by(id=response["run_id"]).one()
        self.assertEqual(run.user_message_id, self.user_message_id)
        db.close()

    async def test_run_resolves_previous_assistant_and_message_url_targets(self):
        fake_runtime = SimpleNamespace(start=lambda _run_id: None)
        request = WorkflowRunRequest(
            session_id="regenerate-chat",
            message="Save https://example.com/source for later.",
            model="test-model",
            selection_mode="explicit",
            workflow_id=self.direct_workflow_id,
        )
        with patch.object(api, "SessionLocal", self.Session), patch.object(api, "runtime", fake_runtime):
            response = await api.create_workflow_run(request)

        db = self.Session()
        run = db.query(WorkflowRun).filter_by(id=response["run_id"]).one()
        run_values = json.loads(run.inputs_json)["run"]
        self.assertEqual(run_values["target_message_id"], self.assistant_message_id)
        self.assertEqual(run_values["target_url"], "https://example.com/source")
        db.close()

    async def test_automatic_run_persists_router_web_search_inputs(self):
        db = self.Session()
        web = db.query(WorkflowDefinition).filter_by(slug="web-answer").one()
        web_id = web.id
        db.close()
        started = []
        fake_runtime = SimpleNamespace(start=started.append)
        router_result = {
            "workflow_id": web_id,
            "workflow_slug": "web-answer",
            "confidence": 0.95,
            "reason": "current information",
            "inputs": {"web_search_query": "Iran news today", "web_search_queries": ["Iran news today", "Iran latest news"]},
            "fallback": False,
        }
        request = WorkflowRunRequest(
            session_id=None,
            message="what happened in iran today",
            model="test-model",
            selection_mode="automatic",
        )
        with (
            patch.object(api, "SessionLocal", self.Session),
            patch.object(api, "runtime", fake_runtime),
            patch.object(api, "select_workflow", new=AsyncMock(return_value=router_result)),
        ):
            response = await api.create_workflow_run(request)

        self.assertEqual(started, [response["run_id"]])
        db = self.Session()
        run = db.query(WorkflowRun).filter_by(id=response["run_id"]).one()
        run_values = json.loads(run.inputs_json)["run"]
        self.assertEqual(run_values["web_search_query"], "Iran news today")
        self.assertEqual(run_values["web_search_queries"], ["Iran news today", "Iran latest news"])
        db.close()

    async def test_interrupted_run_event_stream_emits_terminal_event(self):
        db = self.Session()
        workflow = db.query(WorkflowDefinition).filter_by(slug="research").one()
        run = WorkflowRun(
            workflow_id=workflow.id,
            workflow_revision_id=workflow.current_revision_id,
            status="interrupted",
            selection_mode="automatic",
            inputs_json=json.dumps({"input": {"prompt": "x"}, "run": {}}),
            error_json=json.dumps({"message": "Backend restarted before the workflow completed."}),
            finished_at=datetime.utcnow(),
        )
        db.add(run)
        db.commit()
        run_id = run.id
        db.close()

        with patch.object(api, "SessionLocal", self.Session):
            response = api.get_workflow_events(run_id)
            body = b""
            async for chunk in response.body_iterator:
                body += chunk.encode("utf-8") if isinstance(chunk, str) else chunk

        events = [json.loads(line) for line in body.decode("utf-8").splitlines() if line.strip()]
        interrupted = next(event for event in events if event["type"] == "run_interrupted")
        self.assertEqual(interrupted["payload"]["message"], "Backend restarted before the workflow completed.")