"""InvalidateCacheTool -- clear validation cache for a subject.

Wraps the KV API ``/api/truth/subjects/:subject/invalidate`` endpoint,
which clears all cached validation results for a specific subject
(e.g., "economics", "terminology", "safety").
"""

from __future__ import annotations

import os
from typing import Any, ClassVar

import httpx

from ..base import Tool, ToolParameter, ToolResult

# Read from KV_API_URL environment variable, fallback to localhost
_DEFAULT_KV_API_URL = os.environ.get("KV_API_URL", "http://localhost:41233")
_REQUEST_TIMEOUT = 30.0


class InvalidateCacheTool(Tool):
    """Clear validation cache for a specific subject.

    Forces revalidation of all content related to a subject by clearing
    the cache. Use this after updating documentation for a subject to ensure
    that subsequent validations reflect the latest knowledge.
    """

    name: ClassVar[str] = "invalidate_cache"
    description: ClassVar[str] = (
        "Clear validation cache for a specific subject (e.g., 'economics', "
        "'terminology', 'safety'). Forces fresh validation on next check. "
        "Use this after updating documentation to ensure validations reflect "
        "the latest knowledge base state."
    )
    parameters: ClassVar[list[ToolParameter]] = [
        ToolParameter(
            name="subject",
            type="string",
            description=(
                "Subject identifier to invalidate (e.g., 'economics', 'terminology', "
                "'safety', 'competitors', 'jurisdiction'). Matches the subject "
                "categories used in content validation."
            ),
        ),
        ToolParameter(
            name="kv_api_url",
            type="string",
            description="KV API base URL",
            required=False,
            default=_DEFAULT_KV_API_URL,
        ),
    ]

    async def execute(self, **kwargs: Any) -> ToolResult:
        subject: str = kwargs["subject"]
        kv_api_url: str = kwargs.get("kv_api_url", _DEFAULT_KV_API_URL)

        if not subject:
            return ToolResult.fail("Subject identifier is required")

        async with httpx.AsyncClient(
            base_url=kv_api_url, timeout=_REQUEST_TIMEOUT
        ) as client:
            try:
                resp = await client.post(
                    f"/api/truth/subjects/{subject}/invalidate",
                    json={},
                )
            except httpx.ConnectError:
                return ToolResult.fail(
                    f"Cannot connect to KV API at {kv_api_url}. "
                    "Start it with: cd codebase/tools/platform-knowledge-ai && ./run start"
                )
            except httpx.TimeoutException:
                return ToolResult.fail(
                    f"Cache invalidation timed out after {_REQUEST_TIMEOUT}s"
                )

        if resp.status_code == 404:
            return ToolResult.fail(
                f"Subject '{subject}' not found. Available subjects are determined "
                "by the content classification system."
            )

        if resp.status_code == 400:
            error_data = resp.json() if resp.headers.get("content-type", "").startswith("application/json") else {}
            error_msg = error_data.get("error", "Invalid request")
            return ToolResult.fail(f"Bad request: {error_msg}")

        if resp.status_code >= 500:
            return ToolResult.fail(
                f"KV API internal error (HTTP {resp.status_code}). "
                "Check service logs for details."
            )

        if resp.status_code != 200:
            return ToolResult.fail(
                f"KV API returned unexpected status {resp.status_code}"
            )

        data = resp.json()
        success = data.get("success", False)

        if not success:
            return ToolResult.fail(
                f"Cache invalidation for subject '{subject}' failed. "
                "Check KV API logs for details."
            )

        keys_invalidated = data.get("keysInvalidated", 0)
        affected_locale_files = data.get("affectedLocaleFiles", [])

        return ToolResult.success(
            {
                "subject": subject,
                "keys_invalidated": keys_invalidated,
                "affected_locale_files": affected_locale_files,
                "success": True,
            },
            subject=subject,
            keys_invalidated=keys_invalidated,
        )