from __future__ import annotations

from pathlib import Path
from typing import Any
from uuid import uuid4

import aiosqlite
from pydantic import BaseModel

from duck_core.tasks.store import utc_now


class Conversation(BaseModel):
    id: int | None = None
    conversation_id: str
    title: str
    workspace: str
    created_at: str
    updated_at: str


class ConversationMessage(BaseModel):
    id: int | None = None
    conversation_id: str
    role: str
    content: str
    reasoning_content: str | None = None
    task_id: str | None = None
    status: str | None = None
    created_at: str


class ConversationStore:
    def __init__(self, db_path: str):
        self.db_path = Path(db_path)

    async def init(self) -> None:
        self.db_path.parent.mkdir(parents=True, exist_ok=True)
        async with aiosqlite.connect(self.db_path) as db:
            await db.execute(
                """
                create table if not exists conversations (
                  id integer primary key autoincrement,
                  conversation_id text not null unique,
                  title text not null,
                  workspace text not null,
                  created_at text not null,
                  updated_at text not null
                )
                """
            )
            await db.execute(
                """
                create table if not exists conversation_messages (
                  id integer primary key autoincrement,
                  conversation_id text not null,
                  role text not null,
                  content text not null,
                  reasoning_content text,
                  task_id text,
                  status text,
                  created_at text not null
                )
                """
            )
            await db.commit()

    async def create(self, title: str, workspace: str) -> Conversation:
        await self.init()
        now = utc_now()
        conversation_id = f"chat_{uuid4().hex[:12]}"
        async with aiosqlite.connect(self.db_path) as db:
            cursor = await db.execute(
                """
                insert into conversations(conversation_id, title, workspace, created_at, updated_at)
                values (?, ?, ?, ?, ?)
                """,
                (conversation_id, title, workspace, now, now),
            )
            await db.commit()
            row_id = cursor.lastrowid
        return Conversation(
            id=row_id,
            conversation_id=conversation_id,
            title=title,
            workspace=workspace,
            created_at=now,
            updated_at=now,
        )

    async def ensure(
        self, conversation_id: str | None, title: str, workspace: str
    ) -> Conversation:
        if conversation_id:
            existing = await self.get(conversation_id)
            if existing is not None:
                return existing
        return await self.create(title, workspace)

    async def get(self, conversation_id: str) -> Conversation | None:
        await self.init()
        async with aiosqlite.connect(self.db_path) as db:
            db.row_factory = aiosqlite.Row
            cursor = await db.execute(
                "select * from conversations where conversation_id = ?", (conversation_id,)
            )
            row = await cursor.fetchone()
        return self._row_to_conversation(row) if row else None

    async def list(self, limit: int = 50) -> list[Conversation]:
        await self.init()
        async with aiosqlite.connect(self.db_path) as db:
            db.row_factory = aiosqlite.Row
            cursor = await db.execute(
                "select * from conversations order by updated_at desc limit ?", (limit,)
            )
            rows = await cursor.fetchall()
        return [self._row_to_conversation(row) for row in rows]

    async def add_message(
        self,
        conversation_id: str,
        role: str,
        content: str,
        reasoning_content: str | None = None,
        task_id: str | None = None,
        status: str | None = None,
    ) -> ConversationMessage:
        await self.init()
        now = utc_now()
        async with aiosqlite.connect(self.db_path) as db:
            cursor = await db.execute(
                """
                insert into conversation_messages(
                  conversation_id, role, content, reasoning_content, task_id, status, created_at
                ) values (?, ?, ?, ?, ?, ?, ?)
                """,
                (conversation_id, role, content, reasoning_content, task_id, status, now),
            )
            await db.execute(
                "update conversations set updated_at = ? where conversation_id = ?",
                (now, conversation_id),
            )
            await db.commit()
            row_id = cursor.lastrowid
        return ConversationMessage(
            id=row_id,
            conversation_id=conversation_id,
            role=role,
            content=content,
            reasoning_content=reasoning_content,
            task_id=task_id,
            status=status,
            created_at=now,
        )

    async def list_messages(
        self, conversation_id: str, limit: int | None = None
    ) -> list[ConversationMessage]:
        await self.init()
        sql = "select * from conversation_messages where conversation_id = ? order by id"
        params: tuple[Any, ...] = (conversation_id,)
        if limit is not None:
            sql = (
                "select * from (select * from conversation_messages where conversation_id = ? "
                "order by id desc limit ?) order by id"
            )
            params = (conversation_id, limit)
        async with aiosqlite.connect(self.db_path) as db:
            db.row_factory = aiosqlite.Row
            cursor = await db.execute(sql, params)
            rows = await cursor.fetchall()
        return [self._row_to_message(row) for row in rows]

    async def get_conversation_id_for_task(self, task_id: str) -> str | None:
        await self.init()
        async with aiosqlite.connect(self.db_path) as db:
            cursor = await db.execute(
                """
                select conversation_id from conversation_messages
                where task_id = ?
                order by id
                limit 1
                """,
                (task_id,),
            )
            row = await cursor.fetchone()
        return row[0] if row else None

    def _row_to_conversation(self, row: aiosqlite.Row) -> Conversation:
        return Conversation(
            id=row["id"],
            conversation_id=row["conversation_id"],
            title=row["title"],
            workspace=row["workspace"],
            created_at=row["created_at"],
            updated_at=row["updated_at"],
        )

    def _row_to_message(self, row: aiosqlite.Row) -> ConversationMessage:
        return ConversationMessage(
            id=row["id"],
            conversation_id=row["conversation_id"],
            role=row["role"],
            content=row["content"],
            reasoning_content=row["reasoning_content"],
            task_id=row["task_id"],
            status=row["status"],
            created_at=row["created_at"],
        )