from __future__ import annotations

from datetime import datetime
from enum import Enum
from typing import Optional

from pydantic import BaseModel, Field


# ── Enums ──────────────────────────────────────────────────────────────────────

class ChannelType(str, Enum):
    telegram = "telegram"
    whatsapp = "whatsapp"
    sms = "sms"


class MessageStatus(str, Enum):
    pending = "pending"
    sent = "sent"
    delivered = "delivered"
    read = "read"
    failed = "failed"


class MessageDirection(str, Enum):
    inbound = "inbound"
    outbound = "outbound"


# ── Contact ────────────────────────────────────────────────────────────────────

class ContactCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=255)
    phone: Optional[str] = None
    email: Optional[str] = None
    telegram_id: Optional[str] = None
    telegram_username: Optional[str] = None
    whatsapp_phone: Optional[str] = None
    notes: Optional[str] = None


class ContactUpdate(BaseModel):
    name: Optional[str] = Field(None, min_length=1, max_length=255)
    phone: Optional[str] = None
    email: Optional[str] = None
    telegram_id: Optional[str] = None
    telegram_username: Optional[str] = None
    whatsapp_phone: Optional[str] = None
    notes: Optional[str] = None


class ContactResponse(BaseModel):
    model_config = {"from_attributes": True}

    id: str
    name: str
    phone: Optional[str] = None
    email: Optional[str] = None
    telegram_id: Optional[str] = None
    telegram_username: Optional[str] = None
    whatsapp_phone: Optional[str] = None
    notes: Optional[str] = None
    created_at: datetime
    updated_at: Optional[datetime] = None


# ── Message ────────────────────────────────────────────────────────────────────

class SendMessageRequest(BaseModel):
    channel: ChannelType
    # Empfänger – je nach Kanal eines der Felder befüllen
    recipient_phone: Optional[str] = Field(None, description="Telefonnummer für WhatsApp/SMS (E.164: +49…)")
    recipient_telegram_id: Optional[str] = Field(None, description="Telegram Chat-ID")
    # Optional: Kontakt-ID aus der DB
    contact_id: Optional[str] = None
    text: str = Field(..., min_length=1, max_length=4096)
    reply_to_id: Optional[str] = None


class MessageResponse(BaseModel):
    model_config = {"from_attributes": True}

    id: str
    conversation_id: str
    sender_id: Optional[str] = None
    channel: ChannelType
    channel_message_id: Optional[str] = None
    direction: MessageDirection
    text: str
    status: MessageStatus
    error_message: Optional[str] = None
    created_at: datetime
    sent_at: Optional[datetime] = None
    delivered_at: Optional[datetime] = None
    read_at: Optional[datetime] = None


# ── Conversation ───────────────────────────────────────────────────────────────

class ConversationResponse(BaseModel):
    model_config = {"from_attributes": True}

    id: str
    channel: ChannelType
    channel_conversation_id: Optional[str] = None
    title: Optional[str] = None
    is_group: bool
    is_archived: bool
    last_message_at: Optional[datetime] = None
    created_at: datetime
    last_message: Optional[MessageResponse] = None
    unread_count: int = 0
    contact_id: Optional[str] = None


# ── Channel Status ─────────────────────────────────────────────────────────────

class ChannelStatusResponse(BaseModel):
    channel: ChannelType
    enabled: bool
    connected: bool
    detail: Optional[str] = None


class SystemStatusResponse(BaseModel):
    channels: list[ChannelStatusResponse]
    database: bool
    timestamp: datetime

# ── Auth / User ─────────────────────────────────────────────────────────────

class UserRole(str, Enum):
    admin = "admin"
    user = "user"


class LoginRequest(BaseModel):
    username: str = Field(..., min_length=1, max_length=64)
    password: str = Field(..., min_length=1)


class TokenResponse(BaseModel):
    access_token: str
    token_type: str = "bearer"
    username: str
    role: UserRole


class UserCreate(BaseModel):
    username: str = Field(..., min_length=1, max_length=64)
    password: str = Field(..., min_length=6)
    role: UserRole = UserRole.user


class UserUpdate(BaseModel):
    password: Optional[str] = Field(None, min_length=6)
    role: Optional[UserRole] = None
    is_active: Optional[bool] = None


class UserResponse(BaseModel):
    model_config = {"from_attributes": True}

    id: str
    username: str
    role: UserRole
    is_active: bool
    created_at: datetime