import time
from typing import Any

from sqlalchemy.orm import Session

from app.config import get_settings
from app.integrations.taiga import TaigaClient
from app.projects.service import ProjectService

MAX_PROJECTS_IN_CONTEXT = 20
MAX_OPEN_PER_PROJECT = 8
PROJECTS_CACHE_SEC = 120

_cache: dict[str, Any] = {"data": None, "expires_at": 0.0}


def invalidate_projects_snapshot_cache() -> None:
    _cache["data"] = None
    _cache["expires_at"] = 0.0


def get_projects_snapshot(db: Session, *, force: bool = False) -> dict[str, Any]:
    now = time.time()
    if not force and _cache["data"] is not None and now < _cache["expires_at"]:
        return _cache["data"]

    snapshot = _fetch_projects_snapshot(db)
    _cache["data"] = snapshot
    _cache["expires_at"] = now + PROJECTS_CACHE_SEC
    return snapshot


def _fetch_projects_snapshot(db: Session) -> dict[str, Any]:
    settings = get_settings()
    service = ProjectService(db)

    if not settings.taiga_configured:
        return {"configured": False, "projects": [], "open_items": [], "taiga_open": []}

    projects = service.list_projects()
    if not projects:
        try:
            projects = service.sync_taiga_projects()
        except Exception as exc:
            return {
                "configured": True,
                "projects": [],
                "open_items": [],
                "taiga_open": [],
                "error": str(exc),
            }

    open_items = service.list_work_items(limit=15, status="open")
    taiga_open: list[dict[str, Any]] = []
    fetch_error: str | None = None

    try:
        client = TaigaClient()
        for proj in projects[:MAX_PROJECTS_IN_CONTEXT]:
            stories = client.list_open_userstories(
                proj["taiga_id"], limit=MAX_OPEN_PER_PROJECT
            )
            tasks = client.list_open_tasks(proj["taiga_id"], limit=MAX_OPEN_PER_PROJECT)
            taiga_open.append(
                {
                    "slug": proj["slug"],
                    "name": proj["name"],
                    "stories": [
                        {
                            "ref": s.get("ref"),
                            "subject": s.get("subject", "")[:120],
                        }
                        for s in stories
                    ],
                    "tasks": [
                        {
                            "ref": t.get("ref"),
                            "subject": t.get("subject", "")[:120],
                        }
                        for t in tasks
                    ],
                }
            )
    except Exception as exc:
        fetch_error = str(exc)

    return {
        "configured": True,
        "projects": projects,
        "open_items": open_items,
        "taiga_open": taiga_open,
        "error": fetch_error,
    }


def format_projects_context(snapshot: dict[str, Any]) -> str:
    if not snapshot.get("configured"):
        return "[Taiga/Gitea]\nНе настроено (нет TAIGA_USERNAME/PASSWORD в .env)."

    lines = ["[Проекты и задачи — снимок на начало ответа]"]

    if snapshot.get("error"):
        lines.append(f"⚠ Ошибка загрузки задач из Taiga: {snapshot['error']}")

    projects = snapshot.get("projects") or []
    if not projects:
        lines.append("Проекты Taiga: кэш пуст. Вызови sync_taiga_projects.")
    else:
        lines.append(f"Проекты Taiga ({len(projects)}):")
        for p in projects[:MAX_PROJECTS_IN_CONTEXT]:
            gitea = (
                f"{p.get('gitea_owner')}/{p.get('gitea_repo')}"
                if p.get("gitea_configured")
                else "Gitea не привязан"
            )
            lines.append(f"- `{p.get('slug')}`: {p.get('name')} · {gitea}")

    taiga_open = snapshot.get("taiga_open") or []
    if taiga_open:
        lines.append("")
        lines.append("Открытые задачи в Taiga (live):")
        for block in taiga_open:
            stories = block.get("stories") or []
            tasks = block.get("tasks") or []
            if not stories and not tasks:
                lines.append(f"  `{block.get('slug')}`: нет открытых")
                continue
            lines.append(f"  `{block.get('slug')}`:")
            for story in stories:
                lines.append(f"    story #{story.get('ref')} {story.get('subject')}")
            for task in tasks:
                lines.append(f"    task #{task.get('ref')} {task.get('subject')}")

    open_items = snapshot.get("open_items") or []
    if open_items:
        lines.append("")
        lines.append("Work items созданные ассистентом (локальная БД):")
        for item in open_items[:10]:
            gitea_part = f", gitea #{item.get('gitea_issue')}" if item.get("gitea_issue") else ""
            lines.append(
                f"- #{item.get('taiga_ref')} {item.get('title')} "
                f"({item.get('taiga_slug')}{gitea_part})"
            )

    lines.append("")
    lines.append(
        "Правила: "
        "«какие задачи» → list_taiga_tasks (Taiga API), НЕ list_work_items. "
        "list_work_items — только созданные через ассистента. "
        "Не пиши «ожидаю систему» — сразу вызывай tool или отвечай из снимка выше. "
        "create_work_item — для новых фич/багов из вольного текста."
    )
    return "\n".join(lines)