<?php

namespace App\Services;

use App\Models\Surveillance;
use App\Models\SurveillanceCase;
use App\Models\CaseLabResult;

class DashboardService
{

    /*
    |--------------------------------------------------------------------------
    | Overview Summary Cards
    |--------------------------------------------------------------------------
    */

    public function summaryCards($dateFrom, $dateTo)
    {
        $programs = Surveillance::orderBy('id')->get();
        $results = [];

        foreach ($programs as $program) {

            $current = SurveillanceCase::where('surveillance_id', $program->id)
                ->whereBetween('case_date', [$dateFrom, $dateTo])
                ->count();

            $previous = SurveillanceCase::where('surveillance_id', $program->id)
                ->whereBetween('case_date', [
                    date('Y-m-d', strtotime($dateFrom . ' -7 days')),
                    date('Y-m-d', strtotime($dateFrom . ' -1 day'))
                ])
                ->count();

            $percentChange = $previous > 0
                ? round((($current - $previous) / $previous) * 100, 1)
                : 0;

            $results[] = [
                'surveillance_id' => $program->id,
                'code' => $program->code,
                'current_total' => $current,
                'previous_total' => $previous,
                'percent_change' => $percentChange
            ];
        }

        return $results;
    }


    /*
    |--------------------------------------------------------------------------
    | Fast SARI Summary (single query)
    |--------------------------------------------------------------------------
    */

    public function sariSummaryFast($surveillanceId, $year, $week)
    {

        $row = SurveillanceCase::leftJoin(
            'case_lab_results',
            'surveillance_cases.lab_code',
            '=',
            'case_lab_results.lab_code'
        )

            ->where('surveillance_cases.surveillance_id', $surveillanceId)
            ->where('surveillance_cases.year_data', $year)
            ->where('surveillance_cases.week_data', $week)

            ->selectRaw("
        COUNT(DISTINCT surveillance_cases.lab_code) as total_cases,

        COUNT(DISTINCT CASE
            WHEN case_lab_results.is_positive = 1
            THEN surveillance_cases.lab_code
        END) as overall_positive,

        COUNT(DISTINCT CASE
            WHEN case_lab_results.indicator = 'SARI Influenza Test'
            AND case_lab_results.is_positive = 1
            THEN surveillance_cases.lab_code
        END) as influenza_positive,

        COUNT(DISTINCT CASE
            WHEN case_lab_results.indicator = 'SARI Covid Test'
            AND case_lab_results.is_positive = 1
            THEN surveillance_cases.lab_code
        END) as covid_positive
    ")

            ->first();


        if (!$row || $row->total_cases == 0) {
            return [
                'cases' => 0,
                'overall_rate' => 0,
                'influenza_rate' => 0,
                'covid_rate' => 0
            ];
        }


        return [

            'cases' => $row->total_cases,

            'overall_rate' => round(
                ($row->overall_positive / $row->total_cases) * 100
                ,
                1
            ),

            'influenza_rate' => round(
                ($row->influenza_positive / $row->total_cases) * 100
                ,
                1
            ),

            'covid_rate' => round(
                ($row->covid_positive / $row->total_cases) * 100
                ,
                1
            ),

        ];
    }


    /*
    |--------------------------------------------------------------------------
    | Program Summary
    |--------------------------------------------------------------------------
    */

    public function programSummary($surveillanceId, $startYear, $startWeek, $endYear, $endWeek)
    {

        $prevWeek = $endWeek - 1;
        $prevYear = $endYear;

        if ($prevWeek <= 0) {
            $prevWeek = 52;
            $prevYear--;
        }

        $current = $this->sariSummaryFast($surveillanceId, $endYear, $endWeek);
        $previous = $this->sariSummaryFast($surveillanceId, $prevYear, $prevWeek);


        return [

            'cases' => [
                'current' => $current['cases'],
                'previous' => $previous['cases']
            ],

            'hospital_rate' => [
                'current' => 0,
                'previous' => 0
            ],

            'icu_rate' => [
                'current' => 0,
                'previous' => 0
            ],

            'positivity_rate' => [
                'current' => $current['overall_rate'],
                'previous' => $previous['overall_rate']
            ],

            'influenza_rate' => [
                'current' => $current['influenza_rate'],
                'previous' => $previous['influenza_rate']
            ],

            'covid_rate' => [
                'current' => $current['covid_rate'],
                'previous' => $previous['covid_rate']
            ],

        ];
    }


    /*
    |--------------------------------------------------------------------------
    | Overview Trend
    |--------------------------------------------------------------------------
    */

    public function aggregateAllPrograms($periodType, $startYear, $startWeek, $endYear, $endWeek)
    {

        $data = SurveillanceCase::selectRaw("
                surveillance_id,
                year_data as year,
                week_data as period,
                COUNT(*) as total
            ")

            ->where(function ($q) use ($startYear, $startWeek, $endYear, $endWeek) {

                $q->whereRaw(
                    "(year_data > ? OR (year_data = ? AND week_data >= ?))",
                    [$startYear, $startYear, $startWeek]
                )

                    ->whereRaw(
                        "(year_data < ? OR (year_data = ? AND week_data <= ?))",
                        [$endYear, $endYear, $endWeek]
                    );

            })

            ->groupBy('surveillance_id', 'year_data', 'week_data')
            ->orderBy('year_data')
            ->orderBy('week_data')
            ->get();


        $programs = Surveillance::pluck('code', 'id');

        $results = [];

        foreach ($data as $row) {

            $code = $programs[$row->surveillance_id];

            $results[$code][] = $row;

        }

        return $results;
    }


    /*
    |--------------------------------------------------------------------------
    | Program Dashboard
    |--------------------------------------------------------------------------
    */

    public function programDashboardData($surveillanceId, $startYear, $startWeek, $endYear, $endWeek)
    {

        return [

            'summary' => $this->programSummary(
                $surveillanceId,
                $startYear,
                $startWeek,
                $endYear,
                $endWeek
            ),

            'trend' => $this->trendSingleProgram(
                $surveillanceId,
                $startYear,
                $startWeek,
                $endYear,
                $endWeek
            ),

            'pathogen_distribution' => $this->pathogenDistribution(
                $surveillanceId,
                $startYear,
                $startWeek,
                $endYear,
                $endWeek
            ),

            'age_distribution' => $this->ageDistribution(
                $surveillanceId,
                $startYear,
                $startWeek,
                $endYear,
                $endWeek
            ),

            'sex_distribution' => $this->sexDistribution(
                $surveillanceId,
                $startYear,
                $startWeek,
                $endYear,
                $endWeek
            ),

            'province_distribution' => $this->provinceCirclesProgram(
                $surveillanceId,
                $startYear,
                $startWeek,
                $endYear,
                $endWeek
            )

        ];

    }


    /*
    |--------------------------------------------------------------------------
    | Trend Single Program
    |--------------------------------------------------------------------------
    */

    public function trendSingleProgram($surveillanceId, $startYear, $startWeek, $endYear, $endWeek)
    {

        $rows = SurveillanceCase::leftJoin(
            'case_lab_results',
            'surveillance_cases.lab_code',
            '=',
            'case_lab_results.lab_code'
        )

            ->where('surveillance_cases.surveillance_id', $surveillanceId)

            ->where(function ($q) use ($startYear, $startWeek, $endYear, $endWeek) {

                $q->whereRaw(
                    "(surveillance_cases.year_data > ? OR (surveillance_cases.year_data = ? AND surveillance_cases.week_data >= ?))",
                    [$startYear, $startYear, $startWeek]
                )

                    ->whereRaw(
                        "(surveillance_cases.year_data < ? OR (surveillance_cases.year_data = ? AND surveillance_cases.week_data <= ?))",
                        [$endYear, $endYear, $endWeek]
                    );

            })

            ->selectRaw("
            surveillance_cases.year_data as year,
            surveillance_cases.week_data as period,
            COUNT(DISTINCT surveillance_cases.lab_code) as total_samples,

            ROUND(
            SUM(CASE WHEN case_lab_results.is_positive = 1 THEN 1 ELSE 0 END)
            / NULLIF(COUNT(*),0) * 100,1
            ) as positivity_rate
            ")

            ->groupBy(
                'surveillance_cases.year_data',
                'surveillance_cases.week_data'
            )

            ->get()
            ->keyBy(fn($r) => $r->year . '-' . $r->period);


        $results = [];

        $year = $startYear;
        $week = $startWeek;

        while (true) {

            $key = $year . '-' . $week;

            if (isset($rows[$key])) {

                $results[] = $rows[$key];

            } else {

                $results[] = [
                    'year' => $year,
                    'period' => $week,
                    'total_samples' => 0,
                    'positivity_rate' => 0
                ];

            }

            if ($year == $endYear && $week == $endWeek)
                break;

            $week++;

            if ($week > 52) {
                $week = 1;
                $year++;
            }

        }

        return $results;

    }


    /*
    |--------------------------------------------------------------------------
    | Province Distribution (Program)
    |--------------------------------------------------------------------------
    */

    public function provinceCirclesProgram($surveillanceId, $startYear, $startWeek, $endYear, $endWeek)
    {

        return SurveillanceCase::selectRaw("
                surveillance_cases.site_province_name,
                COUNT(DISTINCT surveillance_cases.lab_code) as total
                ")

            ->join(
                'case_lab_results',
                'surveillance_cases.lab_code',
                '=',
                'case_lab_results.lab_code'
            )

            ->where('surveillance_cases.surveillance_id', $surveillanceId)
            ->where('case_lab_results.is_positive', 1)

            ->where(function ($q) use ($startYear, $startWeek, $endYear, $endWeek) {

                $q->whereRaw(
                    "(surveillance_cases.year_data > ? OR (surveillance_cases.year_data = ? AND surveillance_cases.week_data >= ?))",
                    [$startYear, $startYear, $startWeek]
                )

                    ->whereRaw(
                        "(surveillance_cases.year_data < ? OR (surveillance_cases.year_data = ? AND surveillance_cases.week_data <= ?))",
                        [$endYear, $endYear, $endWeek]
                    );

            })

            ->groupBy('surveillance_cases.site_province_name')
            ->get();

    }


    /*
    |--------------------------------------------------------------------------
    | Pathogen Distribution
    |--------------------------------------------------------------------------
    */

    public function pathogenDistribution($surveillanceId, $startYear, $startWeek, $endYear, $endWeek)
    {

        return CaseLabResult::selectRaw("
                pathogen_name,
                COUNT(*) as total
                ")

            ->join(
                'surveillance_cases',
                'case_lab_results.lab_code',
                '=',
                'surveillance_cases.lab_code'
            )

            ->where('surveillance_cases.surveillance_id', $surveillanceId)
            ->where('case_lab_results.is_positive', 1)

            ->where(function ($q) use ($startYear, $startWeek, $endYear, $endWeek) {

                $q->whereRaw(
                    "(year_data > ? OR (year_data = ? AND week_data >= ?))",
                    [$startYear, $startYear, $startWeek]
                )

                    ->whereRaw(
                        "(year_data < ? OR (year_data = ? AND week_data <= ?))",
                        [$endYear, $endYear, $endWeek]
                    );

            })

            ->groupBy('pathogen_name')
            ->orderByDesc('total')
            ->get();

    }


    /*
    |--------------------------------------------------------------------------
    | Age Distribution
    |--------------------------------------------------------------------------
    */

    public function ageDistribution($surveillanceId, $startYear, $startWeek, $endYear, $endWeek)
    {

        return SurveillanceCase::selectRaw("
                CASE
                WHEN patient_age_inday < 365 THEN '0-1y'
                WHEN patient_age_inday < 1825 THEN '1-5y'
                WHEN patient_age_inday < 6570 THEN '5-18y'
                WHEN patient_age_inday < 21900 THEN '18-60y'
                ELSE '60+y'
                END as age_group,
                COUNT(*) as total
                ")

            ->where('surveillance_id', $surveillanceId)

            ->where(function ($q) use ($startYear, $startWeek, $endYear, $endWeek) {

                $q->whereRaw(
                    "(year_data > ? OR (year_data = ? AND week_data >= ?))",
                    [$startYear, $startYear, $startWeek]
                )

                    ->whereRaw(
                        "(year_data < ? OR (year_data = ? AND week_data <= ?))",
                        [$endYear, $endYear, $endWeek]
                    );

            })

            ->groupBy('age_group')
            ->get();

    }


    /*
    |--------------------------------------------------------------------------
    | Sex Distribution
    |--------------------------------------------------------------------------
    */

    public function sexDistribution($surveillanceId, $startYear, $startWeek, $endYear, $endWeek)
    {

        return SurveillanceCase::selectRaw("
            patient_sex,
            COUNT(*) as total
            ")

            ->where('surveillance_id', $surveillanceId)

            ->where(function ($q) use ($startYear, $startWeek, $endYear, $endWeek) {

                $q->whereRaw(
                    "(year_data > ? OR (year_data = ? AND week_data >= ?))",
                    [$startYear, $startYear, $startWeek]
                )

                    ->whereRaw(
                        "(year_data < ? OR (year_data = ? AND week_data <= ?))",
                        [$endYear, $endYear, $endWeek]
                    );

            })

            ->groupBy('patient_sex')
            ->get();

    }

}