"""One persistent persona for all configured chat/agent providers on this AI Core."""
from contextlib import closing
from pydantic import BaseModel, ConfigDict, Field
from app.database.db import connect


class DialoguePair(BaseModel):
    model_config = ConfigDict(extra="forbid")
    user: str = Field(default="", max_length=8000)
    assistant: str = Field(default="", max_length=8000)


class PersonaSettings(BaseModel):
    model_config = ConfigDict(extra="forbid")
    version: int = Field(default=0, ge=0, le=9007199254740991)
    revision: str = Field(default="", pattern=r"^(?:[0-9a-f]{64})?$")
    name: str = Field(default="", max_length=128)
    system_prompt: str = Field(default="", max_length=16000)
    dialogue_pairs: list[DialoguePair] = Field(default_factory=list, max_length=20)


def connection():
    conn = connect()
    conn.execute("CREATE TABLE IF NOT EXISTS global_persona (id INTEGER PRIMARY KEY CHECK(id=1), data TEXT NOT NULL)")
    return conn


def _desktop():
    from app.config import get_settings
    return get_settings().environment == 'desktop'


def load_persona():
    if _desktop():
        from app.services.desktop_notes import call
        document = call('persona.get', id='default')
        if document is None:
            return PersonaSettings()
        return PersonaSettings.model_validate({**document['record']['data'], 'revision': document['hash']})
    with closing(connection()) as conn:
        row = conn.execute("SELECT data FROM global_persona WHERE id=1").fetchone()
        return PersonaSettings.model_validate_json(row[0]) if row else PersonaSettings()


def legacy_persona_preview():
    """Explicit read-only import source; no automatic Vault ownership inference."""
    from app.errors import ApiError
    from app.services.desktop_notes import call
    if not _desktop():
        raise ApiError(404, 'RESOURCE_NOT_FOUND', '此入口仅用于桌面人设导入。')
    call('persona.get', id='default')  # Revalidate the authenticated Vault at Host.
    with closing(connection()) as conn:
        row = conn.execute("SELECT data FROM global_persona WHERE id=1").fetchone()
        if not row:
            return {'available': False, 'persona': None}
        source = PersonaSettings.model_validate_json(row[0])
        return {'available': True, 'persona': source.model_dump(exclude={'revision'})}


def save_persona(settings):
    if _desktop():
        from uuid import uuid4
        from app import host_bridge
        from app.services.desktop_notes import call
        from app.errors import ApiError
        if settings.version >= 9007199254740991:
            raise ApiError(409, 'PERSONA_VERSION_EXHAUSTED', '人设版本已达到上限。')
        data = settings.model_dump(exclude={'revision'})
        data['version'] += 1
        operation = host_bridge.operation_id.get() or str(uuid4())
        try:
            receipt = call('persona.write', record={'schema': 1, 'kind': 'persona', 'id': 'default', 'data': data},
                           expected=settings.revision, operation_id=operation)
        except ApiError as error:
            if error.code == 'REVISION_CONFLICT':
                raise ApiError(409, 'PERSONA_VERSION_CONFLICT', '当前工作区人设已被修改，请重新打开表单后保存。') from None
            raise
        return PersonaSettings.model_validate({**receipt['record']['data'], 'revision': receipt['hash']})
    from app.errors import ApiError
    with closing(connection()) as conn:
        conn.execute("BEGIN IMMEDIATE")
        try:
            row = conn.execute("SELECT data FROM global_persona WHERE id=1").fetchone()
            current = PersonaSettings.model_validate_json(row[0]) if row else PersonaSettings()
            if current.version != settings.version:
                raise ApiError(409, "PERSONA_VERSION_CONFLICT", "全局人设已被修改，请重新打开表单后保存。")
            updated = settings.model_copy(update={"version": current.version + 1})
            conn.execute("INSERT OR REPLACE INTO global_persona(id,data) VALUES(1,?)", (updated.model_dump_json(),))
            conn.commit()
            return updated
        except BaseException:
            conn.rollback()
            raise


def apply_global_persona(request):
    settings = load_persona()
    parts = [request.system or ""]
    if settings.system_prompt.strip():
        parts.append("全局人设 / Global persona\n" + settings.system_prompt.strip())
    examples = []
    for pair in settings.dialogue_pairs:
        lines = []
        if pair.user.strip(): lines.append("User: " + pair.user.strip())
        if pair.assistant.strip(): lines.append("Assistant: " + pair.assistant.strip())
        if lines: examples.append("\n".join(lines))
    if examples:
        parts.append("预设对话示例 / Example dialogue\n" + "\n\n".join(examples))
    system = "\n\n".join(part for part in parts if part.strip())
    return request.model_copy(update={"system": system or None})