from __future__ import annotations

from yuxi.channels.models import ChatType

TARGET_PREFIX_MAP: dict[str, str] = {
    "chat_id:": "chat_id",
    "chat_guid:": "chat_guid",
    "chat_identifier:": "chat_identifier",
    "handle:": "handle",
    "phone:": "phone",
    "email:": "email",
}

EXPLICIT_TARGET_RE_PREFIXES = (
    "chat_id:",
    "chat_guid:",
    "chat_identifier:",
    "iMessage;",
    "iMessage",
    "handle:",
    "phone:",
    "email:",
)

IMESSAGE_TARGET_PREFIXES = (
    "chat_id:",
    "chat_guid:",
    "chat_identifier:",
    "iMessage;",
    "iMessage",
    "handle:",
    "phone:",
    "email:",
    "tel:",
    "mailto:",
    "+",
)


def parse_target(raw_target: str) -> dict[str, str]:
    """解析目标字符串，返回 {type, value}。

    支持的类型：
    - chat_id:<value>   → chat_id
    - chat_guid:<value> → chat_guid
    - chat_identifier:<value> → chat_identifier (chat_id 或 chat_guid)
    - handle:<value>    → handle
    - phone:<value>     → phone (E.164)
    - email:<value>     → email
    - 其他：自动推断为 handle
    """
    if not raw_target:
        return {"type": "unknown", "value": ""}

    raw_lower = raw_target.lower()
    for prefix, type_name in TARGET_PREFIX_MAP.items():
        if raw_lower.startswith(prefix):
            return {"type": type_name, "value": raw_target[len(prefix) :]}

    if looks_like_explicit_target_id(raw_target):
        if ";-;" in raw_target or "@chat" in raw_target:
            return {"type": "chat_guid", "value": raw_target}
        if raw_target.startswith("iMessage;"):
            return {"type": "chat_id", "value": raw_target}

    if "@" in raw_target and "." in raw_target.split("@")[-1]:
        return {"type": "email", "value": raw_target}

    return {"type": "handle", "value": raw_target}


def looks_like_explicit_target_id(target: str) -> bool:
    return any(target.lower().startswith(p.lower()) for p in EXPLICIT_TARGET_RE_PREFIXES)


def looks_like_imessage_target_id(target: str) -> bool:
    return any(target.lower().startswith(p.lower()) for p in IMESSAGE_TARGET_PREFIXES)


def resolve_chat_type_from_target(target: str) -> ChatType:
    parsed = parse_target(target)
    value = parsed["value"]
    if ";-;" in value or "@chat" in value:
        return ChatType.GROUP
    return ChatType.DIRECT