"""Protocol compliance — current management vs PCDT.

Compares the patient's current treatments and investigations against
the PCDT for the confirmed-or-suspected diagnosis. Flags:
  - PCDT-required exams not performed
  - PCDT-recommended therapies not initiated
  - Therapies in use that are NOT in the PCDT (off-protocol)
  - Specialist referrals that the PCDT requires

Returns a `ProtocolComplianceSpec` with a 0..1 compliance score and
itemised gaps.
"""
from __future__ import annotations
import logging
import re
from typing import Optional

from .types import ProtocolComplianceSpec, ComplianceGap

logger = logging.getLogger("gemeo.protocol_compliance")


def _extract_protocol_items(pcdt: dict, key_options: list) -> list[str]:
    """Pull a flat list of strings from a PCDT field that may be list or text."""
    if not pcdt:
        return []
    out = []
    for k in key_options:
        v = pcdt.get(k)
        if isinstance(v, list):
            out.extend(str(x) for x in v if x)
        elif isinstance(v, str) and v.strip():
            for line in re.split(r"[\n;]", v):
                line = line.strip(" -•·\t")
                if line:
                    out.append(line)
    return [x for x in out if x]


def _matches_any(target: str, candidates: list[str]) -> bool:
    t = (target or "").lower()
    if not t:
        return False
    return any(t in c.lower() or c.lower() in t for c in candidates)


def assess(
    *,
    orpha: Optional[str],
    current_treatments: list = None,
    current_labs: list = None,
    current_imaging: list = None,
) -> ProtocolComplianceSpec:
    """Compute compliance with the PCDT for `orpha`."""
    if not orpha:
        return ProtocolComplianceSpec(disease_orpha=None, score=0.0, gaps=[], notes="No diagnosis provided.")

    try:
        from brazilian_context import get_pcdt
    except ImportError:
        return ProtocolComplianceSpec(disease_orpha=orpha, score=0.0, gaps=[], notes="brazilian_context unavailable.")

    pcdt = None
    try:
        pcdt = get_pcdt(orpha)
    except Exception as e:
        logger.debug(f"get_pcdt failed: {e}")

    if not pcdt:
        return ProtocolComplianceSpec(disease_orpha=orpha, score=0.0, gaps=[], notes=f"No PCDT for ORPHA:{orpha}.")

    pcdt_therapies = _extract_protocol_items(pcdt, ["therapies", "medicamentos", "tratamento"])
    pcdt_exams = _extract_protocol_items(pcdt, ["exames", "investigacao", "diagnostico", "criterios"])
    pcdt_referrals = _extract_protocol_items(pcdt, ["especialidades", "especialistas", "encaminhamento"])

    current_tx_names = [
        (t.get("name") if isinstance(t, dict) else str(t)) for t in (current_treatments or [])
    ]
    current_tx_names = [n for n in current_tx_names if n]

    current_lab_names = [
        (l.get("test") if isinstance(l, dict) else str(l)) for l in (current_labs or [])
    ]
    current_lab_names = [n for n in current_lab_names if n]

    current_imaging_names = [
        ((i.get("modality") or "") + " " + (i.get("finding") or "") if isinstance(i, dict) else str(i))
        for i in (current_imaging or [])
    ]

    gaps: list[ComplianceGap] = []
    n_required = len(pcdt_therapies) + len(pcdt_exams) + len(pcdt_referrals)
    n_satisfied = 0

    for tx in pcdt_therapies:
        if _matches_any(tx, current_tx_names):
            n_satisfied += 1
        else:
            gaps.append(ComplianceGap(
                category="therapy",
                expected=tx,
                priority="high",
                rationale=f"PCDT recommends {tx}; not present in current treatments.",
            ))

    for ex in pcdt_exams:
        if _matches_any(ex, current_lab_names + current_imaging_names):
            n_satisfied += 1
        else:
            gaps.append(ComplianceGap(
                category="exam",
                expected=ex,
                priority="medium",
                rationale=f"PCDT requires/expects {ex}; no matching lab/imaging recorded.",
            ))

    for r in pcdt_referrals:
        # we don't have specialist referral state; surface as soft gap
        gaps.append(ComplianceGap(
            category="referral",
            expected=r,
            priority="medium",
            rationale=f"PCDT requires specialist referral: {r}.",
        ))

    # Off-protocol therapies (in use but not in PCDT list)
    for t in current_tx_names:
        if pcdt_therapies and not _matches_any(t, pcdt_therapies):
            gaps.append(ComplianceGap(
                category="off_protocol",
                expected="(remove or justify)",
                got=t,
                priority="low",
                rationale=f"Therapy `{t}` is not part of the PCDT for this disease.",
            ))

    score = (n_satisfied / max(1, n_required)) if n_required else 0.0

    return ProtocolComplianceSpec(
        disease_orpha=orpha,
        score=round(score, 3),
        gaps=gaps,
        notes=(
            f"PCDT items: {n_required} required, {n_satisfied} satisfied. "
            f"{len([g for g in gaps if g.category != 'off_protocol'])} gaps + "
            f"{len([g for g in gaps if g.category == 'off_protocol'])} off-protocol items."
        ),
    )