<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

/**
 * ChunkAudit
 *
 * Audit trail khusus untuk operasi chunk.
 * Append-only — tiada update atau delete.
 *
 * Berbeza dari AuditLog: ChunkAudit menyimpan perubahan teks penuh (old/new final_text)
 * yang terlalu besar untuk JSON kolum dalam audit_logs.
 */
class ChunkAudit extends Model
{
    // Append-only — tiada updated_at
    const UPDATED_AT = null;

    // === Operation constants ===
    const OP_EDIT_FINAL_TEXT = 'edit_final_text';
    const OP_EXCLUDE         = 'exclude';
    const OP_INCLUDE         = 'include';
    const OP_REINDEX         = 'reindex';
    const OP_SPLIT_PARENT    = 'split_parent';
    const OP_SPLIT_CHILD     = 'split_child';

    protected $fillable = [
        'document_chunk_id',
        'user_id',
        'operation',
        'old_final_text',
        'new_final_text',
        'old_status',
        'new_status',
        'metadata',
        'notes',
        'ip_address',
        'created_at',
    ];

    protected $casts = [
        'metadata'   => 'array',
        'created_at' => 'datetime',
    ];

    // =========================================================================
    // RELATIONSHIPS
    // =========================================================================

    public function chunk(): BelongsTo
    {
        return $this->belongsTo(DocumentChunk::class, 'document_chunk_id');
    }

    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    // =========================================================================
    // FACTORY METHOD
    // =========================================================================

    /**
     * Cipta satu rekod audit dengan data dari request semasa.
     *
     * @param int    $chunkId   ID chunk yang terlibat
     * @param string $operation Jenis operasi (guna konstant OP_*)
     * @param array  $data      Data tambahan (old_final_text, new_status, metadata, dll.)
     * @param string|null $notes Nota admin
     */
    public static function record(
        int $chunkId,
        string $operation,
        array $data = [],
        ?string $notes = null
    ): static {
        return static::create(array_merge([
            'document_chunk_id' => $chunkId,
            'user_id'           => auth()->id(),
            'operation'         => $operation,
            'notes'             => $notes,
            'ip_address'        => request()->ip(),
            'created_at'        => now(),
        ], $data));
    }

    // =========================================================================
    // DISPLAY HELPERS
    // =========================================================================

    public function getOperationLabel(): string
    {
        return match ($this->operation) {
            self::OP_EDIT_FINAL_TEXT => 'Edit Final Text',
            self::OP_EXCLUDE         => 'Dikecualikan',
            self::OP_INCLUDE         => 'Dikembalikan',
            self::OP_REINDEX         => 'Reindex',
            self::OP_SPLIT_PARENT    => 'Split (asal)',
            self::OP_SPLIT_CHILD     => 'Split (baharu)',
            default                  => ucfirst(str_replace('_', ' ', $this->operation)),
        };
    }

    public function getOperationBadgeClass(): string
    {
        return match ($this->operation) {
            self::OP_EDIT_FINAL_TEXT => 'bg-primary',
            self::OP_EXCLUDE         => 'bg-secondary',
            self::OP_INCLUDE         => 'bg-success',
            self::OP_REINDEX         => 'bg-info text-dark',
            self::OP_SPLIT_PARENT    => 'bg-warning text-dark',
            self::OP_SPLIT_CHILD     => 'bg-warning text-dark',
            default                  => 'bg-light text-dark border',
        };
    }
}