"""Interaction commands and user intent for Dvādaśa UX."""

import re
from enum import Enum

from pydantic import BaseModel, Field

from fusionagi.schemas.head import HeadId


class UserIntent(str, Enum):
    """User intent derived from commands or natural input."""

    NORMAL = "normal"
    HEAD_STRATEGY = "head_strategy"
    SHOW_DISSENT = "show_dissent"
    RERUN_RISK = "rerun_risk"
    EXPLAIN_REASONING = "explain_reasoning"
    SOURCES = "sources"


# Command patterns: /command [arg] or /command \n prompt
_COMMAND_PATTERNS: list[tuple[re.Pattern[str], UserIntent]] = [
    (re.compile(r"^/head\s+(\w+)(?:\s+(.+))?\s*$", re.I | re.DOTALL), UserIntent.HEAD_STRATEGY),
    (re.compile(r"^/show\s+dissent(?:\s+(.+))?\s*$", re.I | re.DOTALL), UserIntent.SHOW_DISSENT),
    (re.compile(r"^/rerun\s+risk(?:\s+(.+))?\s*$", re.I | re.DOTALL), UserIntent.RERUN_RISK),
    (re.compile(r"^/explain\s+reasoning(?:\s+(.+))?\s*$", re.I | re.DOTALL), UserIntent.EXPLAIN_REASONING),
    (re.compile(r"^/sources(?:\s+(.+))?\s*$", re.I | re.DOTALL), UserIntent.SOURCES),
]


class ParsedCommand(BaseModel):
    """Parsed user command with intent and optional arguments."""

    intent: UserIntent = Field(..., description="Detected intent")
    head_id: HeadId | None = Field(default=None, description="For HEAD_STRATEGY: which head")
    raw_input: str = Field(default="", description="Original user input")
    cleaned_prompt: str = Field(default="", description="Prompt with command stripped if applicable")


def parse_user_input(text: str) -> ParsedCommand:
    """
    Parse user input to detect commands and extract intent.

    Examples:
        "/head strategy" -> HEAD_STRATEGY, head_id=STRATEGY
        "/show dissent" -> SHOW_DISSENT
        "What is X?" -> NORMAL, cleaned_prompt="What is X?"
    """
    stripped = (text or "").strip()
    if not stripped:
        return ParsedCommand(
            intent=UserIntent.NORMAL,
            raw_input=stripped,
            cleaned_prompt=stripped,
        )

    for pattern, intent in _COMMAND_PATTERNS:
        match = pattern.match(stripped)
        if match:
            head_id = None
            cleaned = ""
            if intent == UserIntent.HEAD_STRATEGY:
                arg = (match.group(1) or "").lower()
                rest = match.group(2) if match.lastindex and match.lastindex >= 2 else None
                cleaned = (rest or "").strip()
                try:
                    head_id = HeadId(arg)
                except ValueError:
                    head_id = None
            else:
                rest = match.group(1) if match.lastindex and match.lastindex >= 1 else None
                cleaned = (rest or "").strip()
            return ParsedCommand(
                intent=intent,
                head_id=head_id,
                raw_input=stripped,
                cleaned_prompt=cleaned,
            )

    return ParsedCommand(
        intent=UserIntent.NORMAL,
        raw_input=stripped,
        cleaned_prompt=stripped,
    )


__all__ = [
    "UserIntent",
    "ParsedCommand",
    "parse_user_input",
]