from __future__ import annotations

import json
from dataclasses import dataclass
from typing import Any, Awaitable, Callable, Optional

from sqlalchemy import and_, func, select
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.tld_prices import get_trending_tlds
from app.models.auction import DomainAuction
from app.models.domain import Domain
from app.models.listing import DomainListing, ListingStatus
from app.models.subscription import Subscription, SubscriptionTier
from app.models.user import User
from app.services.analyze.service import get_domain_analysis
from app.services.zone_file import get_dropped_domains


ToolHandler = Callable[[AsyncSession, User, dict[str, Any]], Awaitable[dict[str, Any]]]


@dataclass(frozen=True)
class ToolDef:
    name: str
    description: str
    json_schema: dict[str, Any]
    min_tier: SubscriptionTier = SubscriptionTier.TRADER
    handler: ToolHandler | None = None


def _tier_level(tier: SubscriptionTier) -> int:
    if tier == SubscriptionTier.TYCOON:
        return 3
    if tier == SubscriptionTier.TRADER:
        return 2
    return 1


async def _get_subscription(db: AsyncSession, user: User) -> Subscription | None:
    res = await db.execute(select(Subscription).where(Subscription.user_id == user.id))
    return res.scalar_one_or_none()


def _require_tier(user_tier: SubscriptionTier, tool_tier: SubscriptionTier) -> None:
    if _tier_level(user_tier) < _tier_level(tool_tier):
        raise PermissionError(f"Tool requires {tool_tier.value} tier.")


def _clamp_int(value: Any, *, lo: int, hi: int, default: int) -> int:
    try:
        v = int(value)
    except Exception:
        return default
    return max(lo, min(hi, v))


def _clamp_float(value: Any, *, lo: float, hi: float, default: float) -> float:
    try:
        v = float(value)
    except Exception:
        return default
    return max(lo, min(hi, v))


# ============================================================================
# TOOL IMPLEMENTATIONS (READ-ONLY)
# ============================================================================


async def tool_get_subscription(db: AsyncSession, user: User, args: dict[str, Any]) -> dict[str, Any]:
    sub = await _get_subscription(db, user)
    if not sub:
        return {"tier": "scout", "features": {}, "limits": {}}
    cfg = sub.config
    return {
        "tier": sub.tier.value,
        "tier_name": cfg.get("name"),
        "features": cfg.get("features", {}),
        "limits": {
            "watchlist": sub.domain_limit,
            "portfolio": cfg.get("portfolio_limit"),
            "listings": cfg.get("listing_limit"),
            "sniper": cfg.get("sniper_limit"),
            "history_days": cfg.get("history_days"),
            "check_frequency": cfg.get("check_frequency"),
        },
    }


async def tool_get_dashboard_summary(db: AsyncSession, user: User, args: dict[str, Any]) -> dict[str, Any]:
    # Similar to /dashboard/summary but kept lightweight and tool-friendly.
    now = args.get("now")  # ignored (server time used)
    _ = now
    from datetime import datetime, timedelta

    t = datetime.utcnow()
    active = and_(DomainAuction.is_active == True, DomainAuction.end_time > t)
    total_auctions = (await db.execute(select(func.count(DomainAuction.id)).where(active))).scalar() or 0

    cutoff = t + timedelta(hours=24)
    ending = and_(DomainAuction.is_active == True, DomainAuction.end_time > t, DomainAuction.end_time <= cutoff)
    ending_soon_count = (await db.execute(select(func.count(DomainAuction.id)).where(ending))).scalar() or 0

    ending_rows = (
        await db.execute(select(DomainAuction).where(ending).order_by(DomainAuction.end_time.asc()).limit(10))
    ).scalars().all()

    # Listings counts
    listing_counts = (
        await db.execute(
            select(DomainListing.status, func.count(DomainListing.id))
            .where(DomainListing.user_id == user.id)
            .group_by(DomainListing.status)
        )
    ).all()
    by_status = {str(status): int(count) for status, count in listing_counts}

    trending = await get_trending_tlds(db)

    return {
        "market": {
            "total_auctions": total_auctions,
            "ending_soon_24h": ending_soon_count,
            "ending_soon_preview": [
                {
                    "domain": a.domain,
                    "current_bid": a.current_bid,
                    "platform": a.platform,
                    "end_time": a.end_time.isoformat() if a.end_time else None,
                    "auction_url": a.auction_url,
                }
                for a in ending_rows
            ],
        },
        "listings": {
            "active": by_status.get(ListingStatus.ACTIVE.value, 0),
            "sold": by_status.get(ListingStatus.SOLD.value, 0),
            "draft": by_status.get(ListingStatus.DRAFT.value, 0),
            "total": sum(by_status.values()),
        },
        "tlds": trending,
        "timestamp": t.isoformat(),
    }


async def tool_list_watchlist(db: AsyncSession, user: User, args: dict[str, Any]) -> dict[str, Any]:
    page = _clamp_int(args.get("page"), lo=1, hi=50, default=1)
    per_page = _clamp_int(args.get("per_page"), lo=1, hi=50, default=20)
    offset = (page - 1) * per_page
    total = (await db.execute(select(func.count(Domain.id)).where(Domain.user_id == user.id))).scalar() or 0
    rows = (
        await db.execute(
            select(Domain)
            .where(Domain.user_id == user.id)
            .order_by(Domain.created_at.desc())
            .offset(offset)
            .limit(per_page)
        )
    ).scalars().all()
    return {
        "page": page,
        "per_page": per_page,
        "total": int(total),
        "domains": [
            {
                "id": d.id,
                "name": d.name,
                "status": getattr(d.status, "value", d.status),
                "is_available": bool(d.is_available),
                "registrar": d.registrar,
                "created_at": d.created_at.isoformat() if d.created_at else None,
                "updated_at": d.updated_at.isoformat() if d.updated_at else None,
            }
            for d in rows
        ],
    }


async def tool_analyze_domain(db: AsyncSession, user: User, args: dict[str, Any]) -> dict[str, Any]:
    domain = (args.get("domain") or "").strip()
    if not domain:
        return {"error": "Missing domain"}
    fast = bool(args.get("fast", False))
    refresh = bool(args.get("refresh", False))
    res = await get_domain_analysis(db, domain, fast=fast, refresh=refresh)
    return res.model_dump(mode="json")


async def tool_market_feed(db: AsyncSession, user: User, args: dict[str, Any]) -> dict[str, Any]:
    # Read-only query against DomainAuction similar to /auctions/feed; keep it capped.
    from datetime import datetime, timedelta

    limit = _clamp_int(args.get("limit"), lo=1, hi=50, default=20)
    source = (args.get("source") or "all").lower()
    keyword = (args.get("keyword") or "").strip().lower() or None
    tld = (args.get("tld") or "").strip().lower().lstrip(".") or None
    sort_by = (args.get("sort_by") or "time").lower()
    ending_within = args.get("ending_within_hours")
    ending_within_h = _clamp_int(ending_within, lo=1, hi=168, default=0) if ending_within is not None else None

    now = datetime.utcnow()
    q = select(DomainAuction).where(DomainAuction.is_active == True, DomainAuction.end_time > now)

    if source in ("pounce", "external"):
        q = q.where(DomainAuction.source == source)
    if keyword:
        q = q.where(DomainAuction.domain.ilike(f"%{keyword}%"))
    if tld:
        q = q.where(DomainAuction.domain.ilike(f"%.{tld}"))
    if ending_within_h:
        q = q.where(DomainAuction.end_time <= (now + timedelta(hours=ending_within_h)))

    if sort_by == "score":
        q = q.order_by(DomainAuction.score.desc().nullslast(), DomainAuction.end_time.asc())
    else:
        q = q.order_by(DomainAuction.end_time.asc())

    auctions = (await db.execute(q.limit(limit))).scalars().all()
    return {
        "items": [
            {
                "domain": a.domain,
                "current_bid": a.current_bid,
                "platform": a.platform,
                "end_time": a.end_time.isoformat() if a.end_time else None,
                "bids": a.bids,
                "score": a.score,
                "auction_url": a.auction_url,
                "source": a.source,
            }
            for a in auctions
        ],
        "count": len(auctions),
        "timestamp": now.isoformat(),
    }


async def tool_get_drops(db: AsyncSession, user: User, args: dict[str, Any]) -> dict[str, Any]:
    tld = (args.get("tld") or None)
    hours = _clamp_int(args.get("hours"), lo=1, hi=48, default=24)
    limit = _clamp_int(args.get("limit"), lo=1, hi=100, default=50)
    offset = _clamp_int(args.get("offset"), lo=0, hi=10000, default=0)
    keyword = (args.get("keyword") or None)
    min_length = args.get("min_length")
    max_length = args.get("max_length")
    exclude_numeric = bool(args.get("exclude_numeric", False))
    exclude_hyphen = bool(args.get("exclude_hyphen", False))

    result = await get_dropped_domains(
        db=db,
        tld=(tld.lower().lstrip(".") if isinstance(tld, str) and tld.strip() else None),
        hours=hours,
        min_length=int(min_length) if min_length is not None else None,
        max_length=int(max_length) if max_length is not None else None,
        exclude_numeric=exclude_numeric,
        exclude_hyphen=exclude_hyphen,
        keyword=(str(keyword).strip() if keyword else None),
        limit=limit,
        offset=offset,
    )
    return result


def get_tool_defs() -> list[ToolDef]:
    return [
        ToolDef(
            name="get_subscription",
            description="Get current user's subscription tier, features and limits.",
            json_schema={"type": "object", "properties": {}, "additionalProperties": False},
            min_tier=SubscriptionTier.TRADER,
            handler=tool_get_subscription,
        ),
        ToolDef(
            name="get_dashboard_summary",
            description="Get a compact snapshot: ending auctions, listing stats, trending TLDs.",
            json_schema={"type": "object", "properties": {}, "additionalProperties": False},
            min_tier=SubscriptionTier.TRADER,
            handler=tool_get_dashboard_summary,
        ),
        ToolDef(
            name="list_watchlist",
            description="List user's watchlist domains (monitored domains).",
            json_schema={
                "type": "object",
                "properties": {
                    "page": {"type": "integer", "minimum": 1, "maximum": 50},
                    "per_page": {"type": "integer", "minimum": 1, "maximum": 50},
                },
                "additionalProperties": False,
            },
            min_tier=SubscriptionTier.TRADER,
            handler=tool_list_watchlist,
        ),
        ToolDef(
            name="analyze_domain",
            description="Run Pounce domain analysis (Authority/Market/Risk/Value) for a given domain.",
            json_schema={
                "type": "object",
                "properties": {
                    "domain": {"type": "string"},
                    "fast": {"type": "boolean"},
                    "refresh": {"type": "boolean"},
                },
                "required": ["domain"],
                "additionalProperties": False,
            },
            min_tier=SubscriptionTier.TRADER,
            handler=tool_analyze_domain,
        ),
        ToolDef(
            name="market_feed",
            description="Get current auction feed (filters: source, keyword, tld, ending window).",
            json_schema={
                "type": "object",
                "properties": {
                    "source": {"type": "string", "enum": ["all", "pounce", "external"]},
                    "keyword": {"type": "string"},
                    "tld": {"type": "string"},
                    "sort_by": {"type": "string", "enum": ["time", "score"]},
                    "ending_within_hours": {"type": "integer", "minimum": 1, "maximum": 168},
                    "limit": {"type": "integer", "minimum": 1, "maximum": 50},
                },
                "additionalProperties": False,
            },
            min_tier=SubscriptionTier.TRADER,
            handler=tool_market_feed,
        ),
        ToolDef(
            name="get_drops",
            description="Get recently dropped domains from zone files (auth required).",
            json_schema={
                "type": "object",
                "properties": {
                    "tld": {"type": "string"},
                    "hours": {"type": "integer", "minimum": 1, "maximum": 48},
                    "min_length": {"type": "integer", "minimum": 1, "maximum": 63},
                    "max_length": {"type": "integer", "minimum": 1, "maximum": 63},
                    "exclude_numeric": {"type": "boolean"},
                    "exclude_hyphen": {"type": "boolean"},
                    "keyword": {"type": "string"},
                    "limit": {"type": "integer", "minimum": 1, "maximum": 100},
                    "offset": {"type": "integer", "minimum": 0, "maximum": 10000},
                },
                "additionalProperties": False,
            },
            min_tier=SubscriptionTier.TRADER,
            handler=tool_get_drops,
        ),
    ]


def tools_for_path(path: str) -> list[str]:
    """
    Limit the visible tool list depending on the current Terminal page.
    This keeps prompts smaller and makes the model more decisive.
    """
    p = (path or "").split("?")[0]
    if p.startswith("/terminal/hunt"):
        return ["get_subscription", "get_dashboard_summary", "market_feed", "get_drops", "analyze_domain", "list_watchlist"]
    if p.startswith("/terminal/market"):
        return ["get_subscription", "market_feed", "analyze_domain"]
    if p.startswith("/terminal/watchlist"):
        return ["get_subscription", "list_watchlist", "analyze_domain"]
    # default: allow a safe minimal set
    return ["get_subscription", "get_dashboard_summary", "analyze_domain"]


async def execute_tool(db: AsyncSession, user: User, name: str, args: dict[str, Any], *, path: str) -> dict[str, Any]:
    defs = {t.name: t for t in get_tool_defs()}
    tool = defs.get(name)
    if tool is None or tool.handler is None:
        return {"error": f"Unknown tool: {name}"}

    # Enforce tool allowed on this page
    allowed = set(tools_for_path(path))
    if name not in allowed:
        return {"error": f"Tool not allowed for path: {name}"}

    sub = await _get_subscription(db, user)
    user_tier = sub.tier if sub else SubscriptionTier.SCOUT
    try:
        _require_tier(user_tier, tool.min_tier)
    except PermissionError as e:
        return {"error": str(e)}

    try:
        return await tool.handler(db, user, args or {})
    except Exception as e:
        return {"error": f"{type(e).__name__}: {e}"}


def tool_catalog_for_prompt(path: str) -> list[dict[str, Any]]:
    allowed = set(tools_for_path(path))
    out: list[dict[str, Any]] = []
    for t in get_tool_defs():
        if t.name in allowed:
            out.append(
                {
                    "name": t.name,
                    "description": t.description,
                    "schema": t.json_schema,
                }
            )
    return out