"""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, no identity record, and access to the prototype care team.
  Clinical answers are stored on the server and visible to the assigned doctor under a pseudonym.
  Consent is kept in the dialog state. Existing doctor-less profiles require explicit care opt-in.

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.api.schemas import DemoPersona
from app.core import clock
from app.core.instrument_catalog import Catalog, catalog
from app.core.intake_questions import DIARY_KINDS
from app.core.intake_runtime import intake_enabled, load_runtime
from app.core.interpretation import texts as results_texts
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.audit import audit
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
from app.services import anonymous_care

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 AnonymousIn(BaseModel):
    model_config = ConfigDict(extra="forbid")
    focus: Literal["depression", "ptsd"] | None = None  # what the person suspects; picks the module


# Self-selected focus of an anonymous person → clinical module (PTSD is the veteran module, ADR-010).
_FOCUS_MODULE = {"depression": "depression", "ptsd": "veteran"}


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.get("/patient/demo-personas", response_model=list[DemoPersona])
async def patient_demo_personas() -> list[DemoPersona]:
    """Synthetic ЕМИАС accounts for the patient app sign-in (the demo console has its own `/demo/personas`)."""
    return fixtures.DEMO_PERSONAS


@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 (`/patient/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(body: AnonymousIn | None = None) -> AuthOut:
    """Anonymous sign-in: a fresh random token; care without an identity record.

    The clinical side gets a pseudonymous profile assigned to the prototype care team. It holds
    no identity fields. Legacy clients may supply `focus`; the common stage 1 screening sets modules itself.
    """
    token = secrets.token_hex(TOKEN_LEN // 2)
    focus = body.focus if body is not None else None
    async with get_clinical_session() as s:
        await repo.upsert_profile(
            s, token=token, doctor_id=anonymous_care.doctor_id(), modules=[_FOCUS_MODULE[focus]] if focus else []
        )
    log.info("web auth: anonymous tok=%s", token[:6])
    return AuthOut(token=token, mode="anonymous")


@router.get("/patient/capabilities")
async def patient_capabilities() -> dict[str, bool]:
    """Expose availability without leaking clinical policy or server configuration."""
    return {"primary_screening": intake_enabled()}


@router.post("/me/{token}/doctor/connect")
async def connect_anonymous_doctor(token: str) -> dict[str, bool]:
    """Explicit opt-in for old doctor-less profiles; never reassign an existing doctor."""
    async with get_clinical_session() as s:
        profile = await repo.get_profile(s, token)
        if profile is None:
            raise HTTPException(404, "patient not found")
        if not profile.doctor_id:
            profile.doctor_id = anonymous_care.doctor_id()
            await audit(s, actor=token, action="anonymous_care_opt_in", token=token, ts=clock.now())
    return {"has_doctor": True}


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  # both parts of today's diary
    diary_next: Literal["morning", "evening"] | None = None  # the part still open today


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()
    done_parts = {r.kind for r in records if r.day == diary_day and r.status == "complete"}
    open_parts = [k.removeprefix("diary_") for k in DIARY_KINDS if k not in done_parts]
    diary_done = not open_parts

    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 and bool(profile.doctor_id),
        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(
            # Stage 1 needs no profile: the screening creates it (anonymous people have none before it).
            enabled=intake_enabled(),
            intake=_intake_state(records),
            diary_done=diary_done,
            diary_next=open_parts[0] if open_parts else None,
        ),
    )


class ResultFinding(BaseModel):
    code: str
    title: str


class Conclusion(BaseModel):
    """Preliminary conclusion of stage 1 — a screening result, not a diagnosis."""

    day: date
    title: str
    lines: list[str]
    findings: list[ResultFinding]
    modules: list[str]
    disclaimer: str


class HistoryItem(BaseModel):
    id: str
    kind: str
    kind_title: str
    status: str
    status_title: str
    day: date
    started_at: datetime
    completed_at: datetime | None
    title: str | None  # interpretation shown to the patient when the form was finished
    lines: list[str]


class ResultsOut(BaseModel):
    conclusion: Conclusion | None
    history: list[HistoryItem]


@router.get("/me/{token}/results", response_model=ResultsOut)
async def my_results(token: str) -> ResultsOut:
    """The patient's own questionnaire log: every administration with its date, status and the interpretation that
    was shown when it was finished (stored with the record, so it never changes afterwards). No raw answers."""
    async with get_clinical_session() as s:
        records = list(
            (
                await s.scalars(
                    select(QuestionnaireRecord)
                    .where(QuestionnaireRecord.token == token)
                    .order_by(QuestionnaireRecord.started_at.desc(), QuestionnaireRecord.id)
                )
            ).all()
        )
    t = results_texts()
    intake = next((r for r in records if r.kind == "intake" and r.status == "complete"), None)
    conclusion = None
    if intake and intake.details.get("interpretation"):
        i = intake.details["interpretation"]
        conclusion = Conclusion(
            day=intake.day,
            title=i["title"],
            lines=i["lines"],
            findings=[ResultFinding(**f) for f in i.get("findings", [])],
            modules=i.get("modules", []),
            disclaimer=i.get("disclaimer", t["disclaimer"]),
        )
    history = [
        HistoryItem(
            id=r.id,
            kind=r.kind,
            kind_title=t["kinds"].get(r.kind, r.kind),
            status=r.status,
            status_title=t["status"].get(r.status, r.status),
            day=r.day,
            started_at=r.started_at,
            completed_at=r.completed_at,
            title=(r.details.get("interpretation") or {}).get("title"),
            lines=(r.details.get("interpretation") or {}).get("lines", []),
        )
        for r in records
    ]
    return ResultsOut(conclusion=conclusion, history=history)


@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"}