"""Patient web app: sign-in, the patient's own plan and public reference data (`/api/v1/auth/*`, `/me/*`,
`/crisis/resources`, `/instruments/catalog`, `/meds/reference`).

The web app is one more channel of the same dialog engine: after sign-in it talks to `/dialog/{token}/...`
exactly like the web console, and consent, onboarding, scales and check-ins come from the engine.

Two ways in:
- **ЕМИАС** (demo): the doctor's one-time connect code via `EmiasMock`, or a synthetic demo persona. The
  patient is linked to the attending doctor, who sees the data on the dashboard.
- **Anonymous**: a random pseudonymous token and nothing else — no identity record, no doctor. The engine
  supports tokens without an identity record (consent is kept in the dialog state), so no personal data is
  stored at all. Crisis safety still works: the fixed crisis script does not depend on the doctor.

The token returned here is the session credential of the prototype. Production needs short-lived sessions
issued by the server instead of handing out the pseudonymous token itself.
"""

import logging
import secrets
from collections import defaultdict
from datetime import date, datetime, time, timedelta
from typing import Any, Literal
from zoneinfo import ZoneInfo

from fastapi import APIRouter, HTTPException
from pydantic import BaseModel, ConfigDict, Field
from sqlalchemy import select

from app.api import fixtures
from app.core import clock
from app.core.instrument_catalog import Catalog, catalog
from app.core.intake_runtime import intake_enabled, load_runtime
from app.core.meds_reference import find_drug, indication_for, load_reference
from app.core.safety import CrisisResource, crisis_reply
from app.db import repo
from app.db.clinical import DailyCheckin, Dose, Prescription
from app.db.identity import TOKEN_LEN
from app.db.intake import QuestionnaireRecord
from app.db.session import get_clinical_session
from app.integrations.emias_mock import CODE_MAX_LEN, EmiasMock

log = logging.getLogger(__name__)

router = APIRouter(tags=["patient-web"])
_emias = EmiasMock()


class AuthOut(BaseModel):
    token: str
    mode: Literal["emias", "anonymous"]
    display_name: str | None = None  # only for ЕМИАС sign-in; anonymous has none by design


class EmiasCodeIn(BaseModel):
    model_config = ConfigDict(extra="forbid", str_strip_whitespace=True)
    code: str = Field(min_length=1, max_length=CODE_MAX_LEN)


class EmiasDemoIn(BaseModel):
    model_config = ConfigDict(extra="forbid")
    persona_token: str = Field(min_length=1, max_length=64)


async def _attach_doctor(token: str, doctor_id: str) -> None:
    async with get_clinical_session() as s:
        if await repo.get_profile(s, token) is None:
            await repo.upsert_profile(s, token=token, doctor_id=doctor_id)


async def _seed_demo_persona(token: str) -> None:
    """Synthetic clinical start for a demo persona (no `make seed` yet): profile, prescription, today's doses.

    Idempotent: only missing pieces are created. Data mirror the dashboard fixtures, so the patient app and the
    doctor's card tell the same story.
    """
    card = fixtures.card(token)
    item = next((p for p in fixtures.PATIENTS if p.token == token), None)
    if card is None or item is None:
        return
    now = clock.now()
    today = now.date()
    async with get_clinical_session() as s:
        if await repo.get_profile(s, token) is None:
            await repo.upsert_profile(
                s,
                token=token,
                doctor_id=fixtures.DOCTOR_ID,
                modules=list(item.modules),
                therapy_start=min((p.start_date for p in card.prescriptions if p.start_date), default=today),
                next_visit=today + timedelta(days=15),
            )
        if await s.scalar(select(Prescription.id).where(Prescription.token == token)) is not None:
            return
        for p in card.prescriptions:
            rx = Prescription(
                token=token, drug=p.drug, dose=p.dose, schedule=p.schedule, start_date=p.start_date or today
            )
            s.add(rx)
            await s.flush()
            # The dose history of the dashboard story (days before today), so the week marks match the doctor's card.
            for d in card.doses:
                if d.drug == p.drug and d.planned_at.astimezone(now.tzinfo).date() < today:
                    s.add(Dose(token=token, prescription_id=rx.id, planned_at=d.planned_at, status=d.status))
            for t in p.schedule.get("times", []):
                hh, mm = (int(x) for x in t.split(":"))
                s.add(
                    Dose(
                        token=token, prescription_id=rx.id, planned_at=datetime.combine(today, time(hh, mm), now.tzinfo)
                    )
                )


@router.post("/auth/emias", response_model=AuthOut)
async def auth_emias(body: EmiasCodeIn) -> AuthOut:
    """Sign-in through ЕМИАС (demo: one-time connect code from the doctor)."""
    person = await _emias.verify(body.code)
    if person is None:
        log.info("web auth: emias code rejected")
        raise HTTPException(401, "code not accepted")
    await _attach_doctor(person.token, person.doctor_id)
    log.info("web auth: emias tok=%s", person.token[:6])
    return AuthOut(token=person.token, mode="emias")


@router.post("/auth/emias/demo", response_model=AuthOut)
async def auth_emias_demo(body: EmiasDemoIn) -> AuthOut:
    """Demo ЕМИАС account: signs in as one of the synthetic personas (`/demo/personas`)."""
    persona = next((p for p in fixtures.DEMO_PERSONAS if p.token == body.persona_token), None)
    if persona is None:
        raise HTTPException(404, "persona not found")
    await _seed_demo_persona(persona.token)
    log.info("web auth: emias demo tok=%s", persona.token[:6])
    return AuthOut(token=persona.token, mode="emias", display_name=persona.display_name)


@router.post("/auth/anonymous", response_model=AuthOut)
async def auth_anonymous() -> AuthOut:
    """Anonymous sign-in: a fresh random token; nothing about the person is stored anywhere."""
    token = secrets.token_hex(TOKEN_LEN // 2)
    log.info("web auth: anonymous tok=%s", token[:6])
    return AuthOut(token=token, mode="anonymous")


class DoseItem(BaseModel):
    id: int
    drug: str
    dose: str
    time: str  # HH:MM, patient's local time
    status: Literal["taken", "missed", "skipped", "pending"]


class WeekDay(BaseModel):
    day: date
    status: Literal["taken", "missed", "pending", "none"]


class PrescriptionItem(BaseModel):
    drug: str
    dose: str
    times: list[str]
    week: list[WeekDay]  # Mon..Sun of the current week
    ref_id: str | None = None  # entry of /meds/reference, if the drug is covered
    indication: Literal["depression", "ptsd"] | None = None
    start_date: date | None = None
    therapy_day: int | None = None  # 1 on the start date (spec: M5, «ожидаемый эффект» cards on days 1/7/14)


class Questionnaires(BaseModel):
    """Questionnaire state for the home screen. Answers and scores are not exposed here."""

    enabled: bool
    intake: Literal["none", "active", "paused", "complete", "review"]
    diary_done: bool


class TodayOut(BaseModel):
    today: date
    now: str  # HH:MM on the (demo) clock — the client never uses its own clock
    has_doctor: bool
    checkin_done: bool
    next_visit: date | None
    doses: list[DoseItem]
    prescriptions: list[PrescriptionItem]
    questionnaires: Questionnaires


def _intake_state(records: list[QuestionnaireRecord]) -> Literal["none", "active", "paused", "complete", "review"]:
    intake = [r for r in records if r.kind == "intake"]
    if any(r.status == "complete" for r in intake):
        return "complete"
    if not intake:
        return "none"
    last = max(intake, key=lambda r: r.started_at).status
    if last in ("active", "paused"):
        return last
    return "review" if last in ("review_required", "interrupted") else "none"


def _day_status(statuses: list[str]) -> Literal["taken", "missed", "pending", "none"]:
    if not statuses:
        return "none"
    if any(s in ("missed", "skipped") for s in statuses):
        return "missed"
    return "taken" if all(s == "taken" for s in statuses) else "pending"


@router.get("/me/{token}/today", response_model=TodayOut)
async def my_today(token: str) -> TodayOut:
    """The patient's own plan for today (home screen) and this week's dose marks (medication screen).

    Only the patient's own prescription data; no scores, no alerts. Anonymous tokens have no profile → empty plan.
    """
    now = clock.now()
    today = now.date()
    week_start = today - timedelta(days=today.weekday())
    async with get_clinical_session() as s:
        profile = await repo.get_profile(s, token)
        prescriptions = (await s.scalars(select(Prescription).where(Prescription.token == token))).all()
        doses = (
            await s.scalars(
                select(Dose)
                .where(Dose.token == token, Dose.planned_at >= datetime.combine(week_start, time.min, now.tzinfo))
                .order_by(Dose.planned_at)
            )
        ).all()
        checkin = await s.scalar(select(DailyCheckin).where(DailyCheckin.token == token, DailyCheckin.day == today))
        records = list((await s.scalars(select(QuestionnaireRecord).where(QuestionnaireRecord.token == token))).all())

    by_rx: dict[int, Prescription] = {p.id: p for p in prescriptions}
    today_doses: list[DoseItem] = []
    marks: dict[tuple[int, date], list[str]] = defaultdict(list)
    for d in doses:
        local = d.planned_at.astimezone(now.tzinfo)
        marks[(d.prescription_id, local.date())].append(d.status)
        rx = by_rx.get(d.prescription_id)
        if local.date() == today and rx is not None:
            today_doses.append(
                DoseItem(id=d.id, drug=rx.drug, dose=rx.dose, time=local.strftime("%H:%M"), status=d.status)
            )
    week = [week_start + timedelta(days=i) for i in range(7)]
    modules = list(profile.modules or []) if profile else []
    diary_day = now.astimezone(ZoneInfo(load_runtime().timezone)).date()
    diary_done = any(r.kind == "diary" and r.day == diary_day and r.status == "complete" for r in records)

    def item(p: Prescription) -> PrescriptionItem:
        ref = find_drug(p.drug)
        return PrescriptionItem(
            drug=p.drug,
            dose=p.dose,
            times=list((p.schedule or {}).get("times", [])),
            week=[WeekDay(day=d, status=_day_status(marks[(p.id, d)])) for d in week],
            ref_id=ref["id"] if ref else None,
            indication=indication_for(modules, ref) if ref else None,
            start_date=p.start_date,
            therapy_day=(today - p.start_date).days + 1 if p.start_date else None,
        )

    return TodayOut(
        today=today,
        now=now.strftime("%H:%M"),
        has_doctor=profile is not None,
        checkin_done=(checkin is not None and checkin.mood is not None) or diary_done,
        next_visit=profile.next_visit if profile else None,
        doses=today_doses,
        prescriptions=[
            item(p)
            for p in prescriptions
            if (p.end_date is None or p.end_date >= today) and (p.start_date is None or p.start_date <= today)
        ],
        questionnaires=Questionnaires(
            enabled=intake_enabled() and profile is not None,
            intake=_intake_state(records),
            diary_done=diary_done,
        ),
    )


@router.get("/crisis/resources", response_model=list[CrisisResource])
async def crisis_resources() -> list[CrisisResource]:
    """Help lines for the always-visible «help now» button — the same list as the fixed crisis script."""
    return crisis_reply([], "patient").resources


@router.get("/instruments/catalog", response_model=Catalog)
async def instruments_catalog() -> Catalog:
    """Form, position and recall period of every questionnaire item, for the question screen header."""
    return catalog()


@router.get("/meds/reference")
async def meds_reference() -> dict[str, Any]:
    """Patient drug reference (draft from the Minzdrav guidelines): expected effect, course, side effects, red flags.

    The internal rule parameters stay on the server.
    """
    ref = load_reference()
    return {k: v for k, v in ref.items() if k != "rules"}