<?php

namespace App\Models;

use Carbon\CarbonImmutable;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Model;

class AttendanceDay extends Model
{
    protected $table = 'attendance_day'; // Because you store created_at/updated_at but CI didn't auto-manage them
    public $timestamps = true;
    protected $fillable = [
        'class_section_id',
        'date',
        'status',
        'submitted_by',
        'submitted_at',
        'published_by',
        'published_at',
        'auto_publish_at',
        'reopened_by',
        'reopened_at',
        'reopen_reason',
        'semester',
        'school_year',
        'created_at',
        'updated_at',
    ];

    protected $casts = [
        'class_section_id' => 'integer',
        'date'             => 'date:Y-m-d',
        'submitted_by'     => 'integer',
        'published_by'     => 'integer',
        'reopened_by'      => 'integer',
        'submitted_at'     => 'datetime',
        'published_at'     => 'datetime',
        'auto_publish_at'  => 'datetime',
        'reopened_at'      => 'datetime',
        'created_at'       => 'datetime',
        'updated_at'       => 'datetime',
    ];

    /* ============================================================
     * Helpers
     * ============================================================
     */

    /**
     * Legacy helper kept for compatibility.
     * True iff this (section, date, term) is hard-locked for everyone.
     * Treats 'published' (new) and 'finalized' (old) as finalized.
     */
    public static function isFinalized(
        int $classSectionId,
        string $date,
        ?string $semester = null,
        ?string $schoolYear = null
    ): bool {
        $q = static::query()
            ->select('id')
            ->where('class_section_id', $classSectionId)
            ->whereDate('date', $date)
            ->where(function (Builder $w) {
                $w->where('status', 'published')
                  ->orWhere('status', 'finalized'); // tolerate legacy data
            });

        if ($semester !== null)   $q->where('semester', $semester);
        if ($schoolYear !== null) $q->where('school_year', $schoolYear);

        return $q->exists();
    }

    /**
     * Find a day row by (section, date, term). Returns model|null.
     */
    public static function findBySectionDate(
        int $classSectionId,
        string $date,
        ?string $semester,
        ?string $schoolYear
    ): ?self {
        return static::query()
            ->where([
                'class_section_id' => $classSectionId,
                'date'             => $date,
                'semester'         => $semester,
                'school_year'      => $schoolYear,
            ])->first();
    }

    /**
     * Get the draft row for (section,date,term), creating it if missing.
     * Relies on the unique key (class_section_id, date, semester, school_year) to prevent duplicates.
     */
    public static function getOrCreateDraft(
        int $classSectionId,
        string $date,
        ?string $semester,
        ?string $schoolYear,
        int $userId = 0
    ): self {
        $now = CarbonImmutable::now('UTC');

        // firstOrCreate is already race-safe with a DB unique index:
        // if two requests race, one insert wins; the other re-queries.
        return static::query()->firstOrCreate(
            [
                'class_section_id' => $classSectionId,
                'date'             => $date,
                'semester'         => $semester,
                'school_year'      => $schoolYear,
            ],
            [
                'status'          => 'draft',
                'submitted_by'    => null,
                'submitted_at'    => null,
                'published_by'    => null,
                'published_at'    => null,
                'auto_publish_at' => null,
                'reopened_by'     => null,
                'reopened_at'     => null,
                'reopen_reason'   => null,
                'created_at'      => $now,
                'updated_at'      => $now,
            ]
        );
    }

    /**
     * DEPRECATED: Prior code used "finalize" to lock immediately.
     * In the new workflow, "finalize" means "teacher submit".
     */
    public function finalize(int $userId): bool
    {
        return $this->submit($userId, null);
    }

    /**
     * Teacher submit: status => submitted (teacher locked, admin editable).
     * Optionally set auto_publish_at.
     */
    public function submit(int $userId, ?string $autoPublishAt = null): bool
    {
        $now = CarbonImmutable::now('UTC');

        $this->fill([
            'status'          => 'submitted',
            'submitted_by'    => $userId,
            'submitted_at'    => $now,
            'auto_publish_at' => $autoPublishAt,
            'updated_at'      => $now,
        ]);

        return $this->save();
    }

    /**
     * Admin publish (hard lock): status => published.
     */
    public function publish(int $userId): bool
    {
        $now = CarbonImmutable::now('UTC');

        $this->fill([
            'status'       => 'published',
            'published_by' => $userId,
            'published_at' => $now,
            'updated_at'   => $now,
        ]);

        return $this->save();
    }

    /**
     * Admin reopen a submitted/published day back to 'draft' (default) or 'submitted'.
     */
    public function reopen(int $userId, string $toStatus = 'draft', ?string $reason = null): bool
    {
        if (!in_array($toStatus, ['draft', 'submitted'], true)) {
            throw new \InvalidArgumentException('toStatus must be "draft" or "submitted".');
        }

        $now = CarbonImmutable::now('UTC');

        $this->fill([
            'status'        => $toStatus,
            'reopened_by'   => $userId,
            'reopened_at'   => $now,
            'reopen_reason' => $reason,
            'updated_at'    => $now,
        ]);

        return $this->save();
    }
}