"""
School Router — school status, search, register, and admin-editable info.
"""
import os
import json
import uuid as uuid_lib
from typing import Dict, Any, Optional, List
from fastapi import APIRouter, Depends, Query
from pydantic import BaseModel
from modules.logger_tool import initialise_logger
from modules.auth.supabase_bearer import SupabaseBearer
from modules.database.supabase.utils.client import SupabaseServiceRoleClient
import modules.database.tools.neo4j_driver_tools as driver_tools

logger = initialise_logger(__name__, os.getenv("LOG_LEVEL"), os.getenv("LOG_PATH"), 'default', True)
router = APIRouter()


# ─── Helpers ──────────────────────────────────────────────────────────────────

def _get_sb():
    return SupabaseServiceRoleClient()

def _institute_db(neo4j_uuid: str) -> str:
    return f"cc.institutes.{neo4j_uuid}"

def _find_institute_db_by_email(user_email: str) -> Optional[str]:
    """Fallback: scan all institute DBs for the teacher's email."""
    try:
        with driver_tools.get_session(database="system") as s:
            dbs = [r["name"] for r in s.run(
                "SHOW DATABASES YIELD name "
                "WHERE name STARTS WITH 'cc.institutes.' "
                "AND NOT name ENDS WITH '.curriculum' RETURN name"
            )]
        for db in dbs:
            try:
                with driver_tools.get_session(database=db) as s:
                    rec = s.run(
                        "MATCH (t:Teacher) WHERE t.worker_email = $e "
                        "RETURN t.uuid_string AS uuid LIMIT 1",
                        e=user_email
                    ).single()
                    if rec:
                        return db
            except Exception:
                continue
    except Exception as e:
        logger.warning(f"Institute DB scan failed: {e}")
    return None


# ─── Status endpoint ─────────────────────────────────────────────────────────

@router.get("/status")
async def get_school_status(credentials: dict = Depends(SupabaseBearer())) -> Dict[str, Any]:
    """Return the current user's school role, school info, and calendar/timetable setup status."""
    user_id = credentials.get("sub", "")
    user_email = credentials.get("email", "")

    try:
        sb = _get_sb()

        p = sb.supabase.table("profiles").select("school_id").eq("id", user_id).single().execute()
        school_id = (p.data or {}).get("school_id")

        # Fallback: if profiles.school_id not set, check institute_memberships directly
        if not school_id:
            m_fb = sb.supabase.table("institute_memberships").select("institute_id,role").eq("profile_id", user_id).single().execute()
            if m_fb.data and m_fb.data.get("institute_id"):
                school_id = m_fb.data["institute_id"]
                user_role = m_fb.data.get("role") or "teacher"
                # Self-heal: write school_id back to profile
                try:
                    sb.supabase.table("profiles").update({"school_id": str(school_id)}).eq("id", user_id).execute()
                except Exception:
                    pass
            else:
                return {"status": "no_school"}
        else:
            m = sb.supabase.table("institute_memberships").select("role").eq("profile_id", user_id).eq("institute_id", school_id).single().execute()
            user_role = ((m.data or {}).get("role") or "teacher")

        i = sb.supabase.table("institutes").select("id,name,urn,website,address,metadata,neo4j_uuid_string").eq("id", school_id).single().execute()
        inst = i.data or {}
        neo4j_uuid = inst.get("neo4j_uuid_string")
        meta = inst.get("metadata") or {}

    except Exception as e:
        logger.warning(f"Supabase school status query failed: {e}")
        return {"status": "error", "message": str(e)}

    if neo4j_uuid:
        inst_db = _institute_db(neo4j_uuid)
    else:
        inst_db = _find_institute_db_by_email(user_email)
        if not inst_db:
            return {"status": "no_school"}

    school_has_calendar = False
    teacher_has_timetable = False
    timetable_id = None
    periods_template = None

    try:
        with driver_tools.get_session(database=inst_db) as s:
            ay = s.run("MATCH (ay:AcademicYear) RETURN ay LIMIT 1").single()
            school_has_calendar = ay is not None

            st = s.run(
                "MATCH (st:SchoolTimetable) WHERE st.periods_template IS NOT NULL "
                "RETURN st.periods_template AS p LIMIT 1"
            ).single()
            if st:
                periods_template = json.loads(st["p"])

            t = s.run(
                "MATCH (t:Teacher) WHERE t.worker_email = $e "
                "RETURN t.uuid_string AS uuid LIMIT 1",
                e=user_email
            ).single()
            if t:
                teacher_uuid = t["uuid"]
                tt = s.run(
                    "MATCH (t:Teacher {uuid_string: $u})-[:HAS_TIMETABLE]->(tt:TeacherTimetable) "
                    "RETURN tt.uuid_string AS id LIMIT 1",
                    u=teacher_uuid
                ).single()
                if tt:
                    teacher_has_timetable = True
                    timetable_id = tt["id"]
    except Exception as e:
        logger.warning(f"Neo4j school status check failed for {inst_db}: {e}")

    return {
        "status": "ok",
        "user_role": user_role,
        "school_id": str(school_id),
        "institute_db": inst_db,
        "school_has_calendar": school_has_calendar,
        "teacher_has_timetable": teacher_has_timetable,
        "timetable_id": timetable_id,
        "periods_template": periods_template,
        "school_info": {
            "name": inst.get("name", ""),
            "urn": inst.get("urn", ""),
            "website": inst.get("website", ""),
            "address": inst.get("address") or {},
            "headteacher": meta.get("headteacher", ""),
            "term_dates_url": meta.get("term_dates_url", ""),
            "staff_list_url": meta.get("staff_list_url", ""),
        },
    }


# ─── School info update ───────────────────────────────────────────────────────

class SchoolInfoUpdate(BaseModel):
    headteacher: Optional[str] = None
    term_dates_url: Optional[str] = None
    staff_list_url: Optional[str] = None

@router.patch("/info")
async def update_school_info(
    body: SchoolInfoUpdate,
    credentials: dict = Depends(SupabaseBearer())
) -> Dict[str, Any]:
    """Admin: update school metadata fields stored in institutes.metadata jsonb."""
    user_id = credentials.get("sub", "")
    try:
        sb = _get_sb()
        p = sb.supabase.table("profiles").select("school_id").eq("id", user_id).single().execute()
        school_id = (p.data or {}).get("school_id")
        if not school_id:
            return {"status": "error", "message": "No school linked"}

        m = sb.supabase.table("institute_memberships").select("role").eq("profile_id", user_id).eq("institute_id", school_id).single().execute()
        role = ((m.data or {}).get("role") or "teacher")
        if role != "school_admin":
            return {"status": "error", "message": "school_admin role required"}

        i = sb.supabase.table("institutes").select("metadata").eq("id", school_id).single().execute()
        meta = dict((i.data or {}).get("metadata") or {})
        if body.headteacher is not None:
            meta["headteacher"] = body.headteacher
        if body.term_dates_url is not None:
            meta["term_dates_url"] = body.term_dates_url
        if body.staff_list_url is not None:
            meta["staff_list_url"] = body.staff_list_url

        sb.supabase.table("institutes").update({"metadata": meta}).eq("id", school_id).execute()
        return {"status": "ok"}
    except Exception as e:
        logger.error(f"School info update failed: {e}")
        return {"status": "error", "message": str(e)}


# ─── GAIS school search ───────────────────────────────────────────────────────

@router.get("/search")
async def search_schools(
    q: str = Query(..., min_length=2, description="School name, URN, or postcode"),
    limit: int = Query(20, ge=1, le=100),
    status: str = Query("Open", description="Filter by establishment status"),
    credentials: dict = Depends(SupabaseBearer()),
) -> Dict[str, Any]:
    """Search GAIS school reference data by name, URN, or postcode."""
    try:
        sb = _get_sb()
        query = sb.supabase.table("gais_schools").select(
            "urn,name,status,phase,type,street,locality,town,county,postcode,"
            "website,telephone,head_title,head_first_name,head_last_name,"
            "la_code,la_name,number_of_pupils,gender,religious_character,region"
        )
        if status:
            query = query.eq("status", status)

        q_stripped = q.strip()
        if q_stripped.isdigit():
            # URN exact match
            query = query.eq("urn", q_stripped)
        else:
            # Name / postcode trigram search — use ilike on name first, fallback includes postcode
            query = query.ilike("name", f"%{q_stripped}%")

        result = query.limit(limit).execute()
        return {"status": "ok", "schools": result.data or [], "count": len(result.data or [])}
    except Exception as e:
        logger.error(f"School search failed: {e}")
        return {"status": "error", "message": str(e)}


# ─── School registration (onboarding) ────────────────────────────────────────

class SchoolRegisterBody(BaseModel):
    urn: str
    name: str
    address: Optional[Dict[str, Any]] = None
    website: Optional[str] = None
    headteacher: Optional[str] = None

@router.post("/register")
async def register_school(
    body: SchoolRegisterBody,
    credentials: dict = Depends(SupabaseBearer()),
) -> Dict[str, Any]:
    """
    Onboarding: create an institute record from a GAIS-selected school,
    provision the Neo4j database, and link the calling user as school_admin.
    """
    user_id = credentials.get("sub", "")
    user_email = credentials.get("email", "")

    try:
        sb = _get_sb()

        # Prevent duplicate registration
        existing = sb.supabase.table("institutes").select("id").eq("urn", body.urn).execute()
        if existing.data:
            school_id = existing.data[0]["id"]
            # Still link user if not already linked
            _ensure_membership(sb, user_id, school_id, "school_admin")
            sb.supabase.table("profiles").update({"school_id": str(school_id)}).eq("id", user_id).execute()
            return {"status": "already_exists", "school_id": str(school_id)}

        # Build metadata
        meta: Dict[str, Any] = {}
        if body.headteacher:
            meta["headteacher"] = body.headteacher

        institute_data: Dict[str, Any] = {
            "name": body.name,
            "urn": body.urn,
            "status": "active",
            "address": body.address or {},
            "website": body.website or "",
            "metadata": meta,
        }

        ins_result = sb.supabase.table("institutes").insert(institute_data).execute()
        if not ins_result.data:
            return {"status": "error", "message": "Failed to create institute record"}

        school_id = ins_result.data[0]["id"]

        # Provision Neo4j institute database
        try:
            from modules.database.services.provisioning_service import ProvisioningService
            ps = ProvisioningService()
            ps.ensure_school(school_id)
            # Reload institute to get the neo4j_uuid_string set by provisioning
            inst = sb.supabase.table("institutes").select("neo4j_uuid_string").eq("id", school_id).single().execute()
            neo4j_uuid = (inst.data or {}).get("neo4j_uuid_string")
        except Exception as prov_err:
            logger.warning(f"Neo4j provisioning failed for {school_id}: {prov_err}")
            neo4j_uuid = None

        # Link user as school_admin
        _ensure_membership(sb, user_id, school_id, "school_admin")
        sb.supabase.table("profiles").update({"school_id": str(school_id)}).eq("id", user_id).execute()

        return {
            "status": "ok",
            "school_id": str(school_id),
            "neo4j_uuid": neo4j_uuid,
        }

    except Exception as e:
        logger.error(f"School registration failed: {e}")
        return {"status": "error", "message": str(e)}


def _ensure_membership(sb: SupabaseServiceRoleClient, user_id: str, school_id: str, role: str) -> None:
    existing = sb.supabase.table("institute_memberships").select("id").eq("profile_id", user_id).eq("institute_id", school_id).execute()
    if not existing.data:
        sb.supabase.table("institute_memberships").insert({
            "profile_id": user_id,
            "institute_id": school_id,
            "role": role,
        }).execute()


# ─── School Overview ──────────────────────────────────────────────────────────

@router.get("/overview")
async def get_school_overview(
    credentials: dict = Depends(SupabaseBearer()),
) -> Dict[str, Any]:
    """
    Summary dashboard for school admins: staff/student/class counts,
    calendar snapshot (terms, total academic days, current/next term).
    """
    user_id = credentials.get("sub", "")
    sb = _get_sb()

    p = sb.supabase.table("profiles").select("school_id").eq("id", user_id).single().execute()
    school_id = str((p.data or {}).get("school_id") or "")
    if not school_id:
        raise HTTPException(status_code=400, detail="User is not linked to a school")

    # Role check
    mem = (
        sb.supabase.table("institute_memberships")
        .select("role")
        .eq("profile_id", user_id)
        .eq("institute_id", school_id)
        .single()
        .execute()
    )
    user_role = (mem.data or {}).get("role", "teacher")

    # Counts
    staff_roles = ["teacher", "school_admin", "department_head"]
    staff_rows = (
        sb.supabase.table("institute_memberships")
        .select("profile_id", count="exact")
        .eq("institute_id", school_id)
        .in_("role", staff_roles)
        .execute()
    )
    student_rows = (
        sb.supabase.table("institute_memberships")
        .select("profile_id", count="exact")
        .eq("institute_id", school_id)
        .eq("role", "student")
        .execute()
    )
    class_rows = (
        sb.supabase.table("classes")
        .select("id", count="exact")
        .eq("institute_id", school_id)
        .eq("is_active", True)
        .execute()
    )

    # Calendar snapshot from academic_terms
    terms = (
        sb.supabase.table("academic_terms")
        .select("id,term_name,term_number,start_date,end_date")
        .eq("institute_id", school_id)
        .order("term_number")
        .execute()
        .data or []
    )

    # Academic day counts per term
    if terms:
        term_ids = [t["id"] for t in terms]
        day_counts_res = (
            sb.supabase.table("academic_days")
            .select("academic_term_id", count="exact")
            .eq("institute_id", school_id)
            .eq("day_type", "Academic")
            .in_("academic_term_id", term_ids)
            .execute()
        )
        # Supabase doesn't group-by server-side; count manually per term
        all_days = (
            sb.supabase.table("academic_days")
            .select("academic_term_id,day_type")
            .eq("institute_id", school_id)
            .in_("academic_term_id", term_ids)
            .execute()
            .data or []
        )
        from collections import defaultdict
        academic_day_count: Dict[str, int] = defaultdict(int)
        total_day_count: Dict[str, int] = defaultdict(int)
        for d in all_days:
            total_day_count[d["academic_term_id"]] += 1
            if d["day_type"] == "Academic":
                academic_day_count[d["academic_term_id"]] += 1

        from datetime import date
        today_str = str(date.today())
        for t in terms:
            t["academic_days"] = academic_day_count.get(t["id"], 0)
            t["total_days"] = total_day_count.get(t["id"], 0)
            if t["start_date"] <= today_str <= t["end_date"]:
                t["is_current"] = True
            else:
                t["is_current"] = False

    pending_invites = (
        sb.supabase.table("invitations")
        .select("id", count="exact")
        .eq("institute_id", school_id)
        .eq("status", "pending")
        .execute()
    )

    return {
        "status": "ok",
        "user_role": user_role,
        "counts": {
            "staff": staff_rows.count or 0,
            "students": student_rows.count or 0,
            "classes": class_rows.count or 0,
            "pending_invitations": pending_invites.count or 0,
        },
        "terms": terms,
        "has_calendar": len(terms) > 0,
    }


# ─── Calendar days (admin view) ───────────────────────────────────────────────

@router.get("/calendar/days")
async def list_calendar_days(
    term_id: Optional[str] = None,
    credentials: dict = Depends(SupabaseBearer()),
) -> Dict[str, Any]:
    """
    Return academic_days for the school, optionally filtered by term.
    Includes week_cycle from the parent academic_week.
    """
    user_id = credentials.get("sub", "")
    sb = _get_sb()

    p = sb.supabase.table("profiles").select("school_id").eq("id", user_id).single().execute()
    school_id = str((p.data or {}).get("school_id") or "")
    if not school_id:
        raise HTTPException(status_code=400, detail="User is not linked to a school")

    q = (
        sb.supabase.table("academic_days")
        .select("id,date,day_of_week,day_type,academic_week_id,academic_term_id,academic_day_number,excluded_period_codes")
        .eq("institute_id", school_id)
        .order("date")
    )
    if term_id:
        q = q.eq("academic_term_id", term_id)

    days = q.execute().data or []

    # Enrich with week_cycle
    if days:
        week_ids = list({d["academic_week_id"] for d in days if d.get("academic_week_id")})
        weeks = (
            sb.supabase.table("academic_weeks")
            .select("id,week_number,week_cycle")
            .in_("id", week_ids)
            .execute()
            .data or []
        )
        wk_map = {w["id"]: w for w in weeks}
        for d in days:
            wk = wk_map.get(d.get("academic_week_id", ""), {})
            d["week_cycle"] = wk.get("week_cycle", "")
            d["week_number"] = wk.get("week_number")

    return {"status": "ok", "days": days, "total": len(days)}


@router.patch("/calendar/days/{day_id}")
async def update_calendar_day(
    day_id: str,
    body: Dict[str, Any],
    credentials: dict = Depends(SupabaseBearer()),
) -> Dict[str, Any]:
    """
    Override day_type for a single academic day (school admin only).
    Syncs academic_periods: removes periods for non-Academic days,
    creates periods from periods_template for newly-Academic days.
    """
    user_id = credentials.get("sub", "")
    sb = _get_sb()

    p = sb.supabase.table("profiles").select("school_id").eq("id", user_id).single().execute()
    school_id = str((p.data or {}).get("school_id") or "")
    if not school_id:
        raise HTTPException(status_code=400, detail="User is not linked to a school")

    # Verify admin role
    mem = (
        sb.supabase.table("institute_memberships")
        .select("role")
        .eq("profile_id", user_id)
        .eq("institute_id", school_id)
        .single()
        .execute()
    )
    if (mem.data or {}).get("role") not in ("school_admin", "department_head"):
        raise HTTPException(status_code=403, detail="School admin access required")

    # Verify day belongs to school
    day = (
        sb.supabase.table("academic_days")
        .select("*")
        .eq("id", day_id)
        .eq("institute_id", school_id)
        .single()
        .execute()
    ).data
    if not day:
        raise HTTPException(status_code=404, detail="Day not found")

    new_day_type = body.get("day_type", day["day_type"])
    excluded = body.get("excluded_period_codes", day.get("excluded_period_codes") or [])

    valid_types = {"Academic", "Holiday", "Staff", "OffTimetable"}
    if new_day_type not in valid_types:
        raise HTTPException(status_code=400, detail=f"day_type must be one of {sorted(valid_types)}")

    # Update the day
    sb.supabase.table("academic_days").update({
        "day_type": new_day_type,
        "excluded_period_codes": excluded,
    }).eq("id", day_id).execute()

    old_type = day["day_type"]
    periods_changed = 0

    if old_type == "Academic" and new_day_type != "Academic":
        # Remove periods for this day
        del_res = (
            sb.supabase.table("academic_periods")
            .delete()
            .eq("academic_day_id", day_id)
            .execute()
        )
        periods_changed = -(len(del_res.data or []))

    elif old_type != "Academic" and new_day_type == "Academic":
        # Create periods from template
        stt = (
            sb.supabase.table("school_timetables")
            .select("periods_template")
            .eq("institute_id", school_id)
            .order("created_at", desc=True)
            .limit(1)
            .execute()
            .data or []
        )
        template = (stt[0].get("periods_template") or []) if stt else []
        skip = set(excluded)
        new_periods = []
        for period in template:
            if period.get("code") in skip:
                continue
            new_periods.append({
                "academic_day_id": day_id,
                "institute_id": school_id,
                "period_code": period["code"],
                "period_name": period.get("name", period["code"]),
                "start_time": period.get("start_time"),
                "end_time": period.get("end_time"),
                "period_type": period.get("period_type", "lesson"),
            })
        if new_periods:
            ins_res = (
                sb.supabase.table("academic_periods")
                .upsert(new_periods, on_conflict="academic_day_id,period_code")
                .execute()
            )
            periods_changed = len(ins_res.data or [])

    return {
        "status": "ok",
        "day_id": day_id,
        "new_day_type": new_day_type,
        "periods_changed": periods_changed,
    }