from __future__ import annotations

import uuid
from datetime import datetime
from typing import TYPE_CHECKING, NamedTuple

from pydantic import BaseModel, Field

from resonance_engine.dsp.enums import DSPClientName
from resonance_engine.fandata.types import FanRecord
from resonance_engine.tasks.enums import FanoutSource, TaskFinishedReason, TaskStatus

if TYPE_CHECKING:
    from resonance_engine.fandata.models import FanConnectionFilter


class FanCollectBatch(BaseModel):
    collect_task_id: uuid.UUID = Field(default_factory=uuid.uuid4)
    fanout_task_id: uuid.UUID
    dsp_client_name: DSPClientName
    fans: list[FanRecord]
    force: bool = False


class FanoutTaskView(NamedTuple):
    id: uuid.UUID
    started_at: datetime
    finished_at: datetime | None
    source: FanoutSource
    status: TaskStatus
    finished_reason: TaskFinishedReason | None
    fans_dispatched: int
    messages_sent: int
    filters: FanConnectionFilter
    fans_collected: int
    fans_errors: int
    fans_stale_tokens: int
    fans_skipped: int
    requests: int
    requests_rate_limited: int
    collect_tasks_done: int


class FanoutTaskViewPage(NamedTuple):
    items: list[FanoutTaskView]
    next_cursor: str | None
    total: int


class FanoutAggStats(NamedTuple):
    total: int
    running: int
    last_started_at: datetime | None
    last_fans_dispatched: int | None


class CollectAggStats(NamedTuple):
    total: int
    running: int
    stale: int
    last_started_at: datetime | None


class CollectActivityBucket(NamedTuple):
    bucket: str
    dsp_client_name: str
    dsp_client_display_name: str
    fans_processed: int
    fans_errors: int
    fans_stale_tokens: int
    requests_rate_limited: int
    requests: int


class FanoutSignals(NamedTuple):
    rps: float  # requests / drain span — achieved fleet request rate
    reqs_per_fan: float  # requests / fans worked
    duration_s: float  # p90 drain span (overran check)
    latency_s: float  # serial wall-clock per request (Σserial / Σrequests)
    time_per_fan_s: float  # serial wall-clock per fan (Σserial / Σfans) — batch size
    throttle_rate: float  # rate-limited requests / requests — 429 share
    fans_per_s: float  # fans / drain span — fan drain rate; the fanout sizing signal
    last_fans: int  # most recent fanout's worked fans — overrun no-growth cap