from enum import StrEnum
from typing import Literal, Set
from uuid import UUID

import nh3
from pydantic import BaseModel, Field, field_validator

from constants import (
    CHAMP_RAG_ENABLED,
    MAX_COMMENT_LENGTH,
    MAX_FILE_NAME_LENGTH,
    MAX_ID_LENGTH,
    MAX_MESSAGE_LENGTH,
    MAX_RESPONSE_LENGTH,
)


class AgeGroup(StrEnum):
    AGE_0_17 = "0-17"
    AGE_18_24 = "18-24"
    AGE_25_34 = "25-34"
    AGE_35_44 = "35-44"
    AGE_45_54 = "45-54"
    AGE_55_64 = "55-64"
    AGE_65_PLUS = "65+"


class Gender(StrEnum):
    MALE = "male"
    FEMALE = "female"
    NON_BINARY = "non-binary"
    OTHER = "other"
    PREFER_NOT = "prefer-not"


class Role(StrEnum):
    PATIENT = "patient"
    CLINICIAN = "clinician"
    COMPUTER_SCIENTIST = "computer-scientist"
    RESEARCHER = "researcher"
    OTHER = "other"


ModelType = Literal[
    "champ",
    "openai",
    "google-conservative",
    "google-creative",
    "fake",
    "skills_wiki",
]


class IdentifierBase(BaseModel):
    # Participant ID could be in ProfileBase instead. It doesn't really matter.
    participant_id: str = Field(
        pattern="^[a-zA-Z0-9_-]+$", min_length=1, max_length=MAX_ID_LENGTH
    )


class ProfileBase(BaseModel):
    consent: bool
    age_group: AgeGroup
    gender: Gender
    roles: Set[Role] = Field(min_length=1, max_length=5)


class ChatRequest(IdentifierBase, ProfileBase):
    conversation_id: str = Field(
        pattern="^[a-zA-Z0-9_-]+$", min_length=1, max_length=MAX_ID_LENGTH
    )
    lang: Literal["en", "fr"]
    human_message: str = Field(min_length=1, max_length=MAX_MESSAGE_LENGTH)

    @field_validator("human_message")
    def sanitize_human_message(cls, human_message: str):
        """Remove HTML tags to prevent XSS"""
        return nh3.clean(human_message)


class StartConversationRequest(BaseModel):
    model_type: ModelType

    @field_validator("model_type")
    def refuse_rag_champ_when_off(cls, model_type: str) -> str:
        """Refuse the RAG model type (champ) unless CHAMP_RAG_ENABLED turned it on.

        Args:
            model_type (str): The model type asked for.

        Raises:
            ValueError: When it is the RAG model type and that is off; answered with a 422.

        Returns:
            str: The model type.
        """
        if model_type == "champ" and not CHAMP_RAG_ENABLED:
            raise ValueError(
                "the RAG model type 'champ' is turned off (CHAMP_RAG_ENABLED is not true)"
            )
        return model_type


class ClearConversationRequest(BaseModel):
    conversation_id: str = Field(
        pattern="^[a-zA-Z0-9_-]+$", min_length=1, max_length=MAX_ID_LENGTH
    )


class RestoredTurn(BaseModel):
    """A turn as the user saw it, with the figures its reply showed."""

    human_message: str
    reply: str
    reply_id: str
    gwp_kgcoeq: float
    water_L: float
    electricity_kWh: float
    n_tokens: int


class CurrentConversation(BaseModel):
    """A conversation to show again: its turns as the user saw them, and its files' names."""

    conversation_id: str
    model_type: str
    turns: list[RestoredTurn]
    file_names: list[str]


class FeedbackRequest(IdentifierBase, ProfileBase):
    conversation_id: str = Field(
        pattern="^[a-zA-Z0-9_-]+$", min_length=1, max_length=MAX_ID_LENGTH
    )
    message_index: int = Field(ge=0, le=10_000)
    rating: Literal["like", "dislike", "mixed"]
    comment: str = Field(min_length=0, max_length=MAX_COMMENT_LENGTH)
    reply_content: str = Field(min_length=1, max_length=MAX_RESPONSE_LENGTH)
    reply_id: UUID

    @field_validator("comment")
    def sanitize_comment(cls, comment: str):
        """Remove HTML tags to prevent XSS"""
        return nh3.clean(comment)

    @field_validator("reply_content")
    def sanitize_reply_content(cls, reply_content: str):
        """Remove HTML tags to prevent XSS"""
        return nh3.clean(reply_content)


class CommentRequest(IdentifierBase, ProfileBase):
    comment: str = Field(min_length=1, max_length=MAX_COMMENT_LENGTH)
    # The conversation on screen; None when the user hasn't sent a message yet.
    conversation_id: str | None = Field(
        default=None, pattern="^[a-zA-Z0-9_-]+$", min_length=1, max_length=MAX_ID_LENGTH
    )

    @field_validator("comment")
    def sanitize_comment(cls, comment: str):
        """Remove HTML tags to prevent XSS"""
        return nh3.clean(comment)


class DeleteFileRequest(IdentifierBase, ProfileBase):
    conversation_id: str = Field(
        pattern="^[a-zA-Z0-9_-]+$", min_length=1, max_length=MAX_ID_LENGTH
    )
    file_name: str = Field(
        # Matches is_valid_filename in helpers/file_helper.py: block only
        # control characters, path separators, and HTML/attribute-injection
        # characters — everything else a real filename can contain (commas,
        # apostrophes, colons, etc.) is allowed, so anything accepted on
        # upload can also be deleted. The "." / ".." exclusion lives in the
        # validator below — pydantic-core's regex engine has no look-ahead.
        pattern=r'^[^\x00-\x1f\\/<>"]+$',
        min_length=1,
        max_length=MAX_FILE_NAME_LENGTH,
    )

    @field_validator("file_name")
    def reject_dot_names(cls, file_name: str):
        if file_name in {".", ".."}:
            raise ValueError('file_name cannot be "." or ".."')
        return file_name