import json

from django.contrib.auth.decorators import login_required
from django.db import connection
from django.shortcuts import render
from django.utils.translation import get_language

from common.models import UserConfig, Thematic
from reporting.models import ReportingContractConfig


def _can_access_reporting(user):
    if user.is_superuser:
        return True
    try:
        user_config = UserConfig.objects.get(user=user)
        return user_config.can_access_view("reporting")
    except UserConfig.DoesNotExist:
        return False


@login_required
def dashboard(request):
    if not _can_access_reporting(request.user):
        from django.core.exceptions import PermissionDenied
        raise PermissionDenied

    # Determine which contracts are accessible for the selector
    try:
        user_config = UserConfig.objects.prefetch_related("roles").get(user=request.user)
        is_unrestricted = (
            request.user.is_superuser
            or user_config.roles.filter(name__in=["admin", "top_manager", "operator"]).exists()
        )
    except UserConfig.DoesNotExist:
        user_config = None
        is_unrestricted = request.user.is_superuser

    # Reporting-enabled contracts
    enabled_qs = (
        ReportingContractConfig.objects.filter(is_enabled=True)
        .select_related("contract")
        .order_by("contract__contract_number")
    )

    if is_unrestricted:
        accessible_contracts = [
            {"id": rc.contract.id, "number": rc.contract.contract_number}
            for rc in enabled_qs
        ]
    else:
        user_contract_ids = set(
            user_config.contracts.values_list("id", flat=True)
        ) if user_config else set()
        accessible_contracts = [
            {"id": rc.contract.id, "number": rc.contract.contract_number}
            for rc in enabled_qs
            if rc.contract.id in user_contract_ids
        ]

    # Build thematic → contract_ids map from mv_interventions
    # (only corrective interventions with dt_to_be_processed, for accessible contracts)
    accessible_contract_ids = [c["id"] for c in accessible_contracts]
    lang = get_language() or "fr"

    if accessible_contract_ids:
        placeholders = ", ".join(["%s"] * len(accessible_contract_ids))
        sql = f"""
            SELECT
                thematic_id,
                MAX(thematic_name_fr)           AS name_fr,
                MAX(thematic_name_nl)           AS name_nl,
                ARRAY_AGG(DISTINCT contract_id) AS contract_ids
            FROM reporting.mv_interventions
            WHERE maintenance_type = 'corrective'
              AND dt_to_be_processed IS NOT NULL
              AND thematic_id IS NOT NULL
              AND contract_id IN ({placeholders})
            GROUP BY thematic_id
            ORDER BY MAX(thematic_name_fr) ASC
        """
        with connection.cursor() as cursor:
            cursor.execute(sql, accessible_contract_ids)
            rows = cursor.fetchall()

        # Fetch thematic codes to map thematic IDs to codes
        thematic_ids = [r[0] for r in rows]
        thematic_codes = {
            t.id: t.code
            for t in Thematic.objects.filter(id__in=thematic_ids)
        } if thematic_ids else {}

        accessible_thematics = []
        thematic_contract_map = {}  # { thematic_id: [contract_id, ...] }
        thematic_code_map = {}  # { thematic_id: code }
        for thematic_id, name_fr, name_nl, contract_ids in rows:
            name = name_nl if lang == "nl" else name_fr
            contract_ids_clean = sorted(int(c) for c in (contract_ids or []) if c is not None)
            code = thematic_codes.get(thematic_id)
            thematic_code_map[thematic_id] = code
            accessible_thematics.append({
                "id": thematic_id,
                "name": name,
                "name_fr": name_fr,
                "name_nl": name_nl,
                "code": code,
            })
            thematic_contract_map[thematic_id] = contract_ids_clean
    else:
        accessible_thematics = []
        thematic_contract_map = {}
        thematic_code_map = {}

    # Saved preferences for this page
    saved_prefs = {}
    if user_config:
        saved_prefs = (user_config.reporting_preferences or {}).get("dashboard", {})

    return render(request, "reporting/dashboard.html", {
        "accessible_contracts": accessible_contracts,
        "accessible_thematics": accessible_thematics,
        "thematic_contract_map_json": json.dumps(thematic_contract_map),
        "thematic_code_map_json": json.dumps(thematic_code_map),
        "saved_prefs_json": json.dumps(saved_prefs),
    })


@login_required
def volume_dashboard(request):
    if not _can_access_reporting(request.user):
        from django.core.exceptions import PermissionDenied
        raise PermissionDenied

    # Determine which contracts are accessible for the selector
    try:
        user_config = UserConfig.objects.prefetch_related("roles").get(user=request.user)
        is_unrestricted = (
            request.user.is_superuser
            or user_config.roles.filter(name__in=["admin", "top_manager", "operator"]).exists()
        )
    except UserConfig.DoesNotExist:
        user_config = None
        is_unrestricted = request.user.is_superuser

    # Reporting-enabled contracts
    enabled_qs = (
        ReportingContractConfig.objects.filter(is_enabled=True)
        .select_related("contract__company")
        .order_by("contract__contract_number")
    )

    if is_unrestricted:
        accessible_contracts = [
            {
                "id": rc.contract.id,
                "number": rc.contract.contract_number,
                "company_name": rc.contract.company.name
            }
            for rc in enabled_qs
        ]
    else:
        user_contract_ids = set(
            user_config.contracts.values_list("id", flat=True)
        ) if user_config else set()
        accessible_contracts = [
            {
                "id": rc.contract.id,
                "number": rc.contract.contract_number,
                "company_name": rc.contract.company.name
            }
            for rc in enabled_qs
            if rc.contract.id in user_contract_ids
        ]

    # Build thematic → contract_ids map from mv_interventions
    accessible_contract_ids = [c["id"] for c in accessible_contracts]
    lang = get_language() or "fr"

    if accessible_contract_ids:
        placeholders = ", ".join(["%s"] * len(accessible_contract_ids))
        sql = f"""
            SELECT
                thematic_id,
                MAX(thematic_name_fr)           AS name_fr,
                MAX(thematic_name_nl)           AS name_nl,
                ARRAY_AGG(DISTINCT contract_id) AS contract_ids
            FROM reporting.mv_interventions
            WHERE maintenance_type = 'corrective'
              AND dt_to_be_processed IS NOT NULL
              AND thematic_id IS NOT NULL
              AND contract_id IN ({placeholders})
            GROUP BY thematic_id
            ORDER BY MAX(thematic_name_fr) ASC
        """
        with connection.cursor() as cursor:
            cursor.execute(sql, accessible_contract_ids)
            rows = cursor.fetchall()

        # Fetch thematic codes to map thematic IDs to codes
        thematic_ids = [r[0] for r in rows]
        thematic_codes = {
            t.id: t.code
            for t in Thematic.objects.filter(id__in=thematic_ids)
        } if thematic_ids else {}

        accessible_thematics = []
        thematic_contract_map = {}  # { thematic_id: [contract_id, ...] }
        thematic_code_map = {}  # { thematic_id: code }
        for thematic_id, name_fr, name_nl, contract_ids in rows:
            name = name_nl if lang == "nl" else name_fr
            contract_ids_clean = sorted(int(c) for c in (contract_ids or []) if c is not None)
            code = thematic_codes.get(thematic_id)
            thematic_code_map[thematic_id] = code
            accessible_thematics.append({
                "id": thematic_id,
                "name": name,
                "name_fr": name_fr,
                "name_nl": name_nl,
                "code": code,
            })
            thematic_contract_map[thematic_id] = contract_ids_clean
    else:
        accessible_thematics = []
        thematic_contract_map = {}
        thematic_code_map = {}

    # Saved preferences for this page
    saved_prefs = {}
    if user_config:
        saved_prefs = (user_config.reporting_preferences or {}).get("volume_dashboard", {})

    return render(request, "reporting/volume_dashboard.html", {
        "accessible_contracts": accessible_contracts,
        "accessible_thematics": accessible_thematics,
        "thematic_contract_map_json": json.dumps(thematic_contract_map),
        "thematic_code_map_json": json.dumps(thematic_code_map),
        "saved_prefs_json": json.dumps(saved_prefs),
    })


@login_required
def observations_dashboard(request):
    if not _can_access_reporting(request.user):
        from django.core.exceptions import PermissionDenied
        raise PermissionDenied

    # Determine which thematic, category, symptom are accessible
    try:
        user_config = UserConfig.objects.prefetch_related("roles").get(user=request.user)
        is_unrestricted = (
            request.user.is_superuser
            or user_config.roles.filter(name__in=["admin", "top_manager", "operator"]).exists()
        )
    except UserConfig.DoesNotExist:
        user_config = None
        is_unrestricted = request.user.is_superuser

    lang = get_language() or "fr"
    from common.models import Thematic
    from assets.models import AssetCategory
    from interventions.models import Symptom
    from observations.permissions import get_observation_access_context

    if is_unrestricted:
        allowed_tids = list(Thematic.objects.values_list("id", flat=True))
    else:
        access_context = get_observation_access_context(request.user, user_config=user_config)
        allowed_tids = list(access_context.thematic_ids) if access_context else []

    if allowed_tids:
        thematics_qs = Thematic.objects.filter(id__in=allowed_tids).order_by("name_fr")
        all_categories_qs = AssetCategory.objects.filter(thematic_id__in=allowed_tids).order_by("name_fr")
        symptoms_qs = Symptom.objects.filter(thematic_id__in=allowed_tids).order_by("name_fr")

        accessible_thematics = [
            {
                "id": t.id,
                "name": t.name_nl if lang == "nl" else t.name_fr,
                "code": t.code
            }
            for t in thematics_qs
        ]
        
        accessible_categories = [
            {
                "id": c.id,
                "name": c.name_nl if lang == "nl" else c.name_fr,
                "thematic_id": c.thematic_id
            }
            for c in all_categories_qs
        ]

        accessible_symptoms = [
            {
                "id": s.id,
                "name": s.name_nl if lang == "nl" else s.name_fr,
                "thematic_id": s.thematic_id
            }
            for s in symptoms_qs
        ]

        # Build thematic → list of category IDs mapping
        thematic_category_map = {}
        for c in accessible_categories:
            tid = c["thematic_id"]
            if tid not in thematic_category_map:
                thematic_category_map[tid] = []
            thematic_category_map[tid].append(c["id"])

        # Build thematic → list of symptom IDs mapping
        thematic_symptom_map = {}
        for s in accessible_symptoms:
            tid = s["thematic_id"]
            if tid not in thematic_symptom_map:
                thematic_symptom_map[tid] = []
            thematic_symptom_map[tid].append(s["id"])
    else:
        accessible_thematics = []
        accessible_categories = []
        accessible_symptoms = []
        thematic_category_map = {}
        thematic_symptom_map = {}

    # Saved preferences for this page
    saved_prefs = {}
    if user_config:
        saved_prefs = (user_config.reporting_preferences or {}).get("observations_dashboard", {})

    return render(request, "reporting/observations_dashboard.html", {
        "accessible_thematics": accessible_thematics,
        "accessible_categories": accessible_categories,
        "accessible_symptoms": accessible_symptoms,
        "thematic_category_map_json": json.dumps(thematic_category_map),
        "thematic_symptom_map_json": json.dumps(thematic_symptom_map),
        "saved_prefs_json": json.dumps(saved_prefs),
    })