<?php
namespace JVBase\meta;

if (!defined('ABSPATH')) {
	exit;
}

/**
 * Fluent accessor for repeater field operations
 *
 * Usage:
 *   $meta->repeater('gallery')->field(0, 'image');
 *   $meta->repeater('links')->addRow(['url' => '...', 'title' => '...']);
 *   $meta->repeater('gallery')->setField(0, 'caption', 'New caption');
 */
class Repeater
{
	protected Meta $meta;
	protected string $name;
	protected array $data;
	protected array $config;

	public function __construct(Meta $meta, string $name)
	{
		$this->meta = $meta;
		$this->name = $name;
		$this->data = $meta->get($name) ?: [];
		$this->config = $meta->config($name) ?? [];

		// Ensure data is array
		if (!is_array($this->data)) {
			$this->data = [];
		}
	}

	// ─────────────────────────────────────────────────────────────
	// Read Operations
	// ─────────────────────────────────────────────────────────────

	/**
	 * Get all rows
	 */
	public function all(): array
	{
		return $this->data;
	}

	/**
	 * Get a specific row
	 */
	public function row(int $index): ?array
	{
		return $this->data[$index] ?? null;
	}

	/**
	 * Get first row
	 */
	public function first(): ?array
	{
		return $this->data[0] ?? null;
	}

	/**
	 * Get last row
	 */
	public function last(): ?array
	{
		if (empty($this->data)) {
			return null;
		}
		return $this->data[array_key_last($this->data)];
	}

	/**
	 * Get field value from specific row
	 */
	public function field(int $index, string $field): mixed
	{
		return $this->data[$index][$field] ?? null;
	}

	/**
	 * Get row count
	 */
	public function count(): int
	{
		return count($this->data);
	}

	/**
	 * Check if empty
	 */
	public function isEmpty(): bool
	{
		return empty($this->data);
	}

	/**
	 * Check if row exists
	 */
	public function hasRow(int $index): bool
	{
		return isset($this->data[$index]);
	}

	// ─────────────────────────────────────────────────────────────
	// Write Operations
	// ─────────────────────────────────────────────────────────────

	/**
	 * Set field value in specific row
	 */
	public function setField(int $index, string $field, mixed $value): self
	{
		if (!isset($this->data[$index])) {
			$this->data[$index] = [];
		}

		$this->data[$index][$field] = $value;
		$this->sync();

		return $this;
	}

	/**
	 * Add a new row
	 */
	public function addRow(array $data = []): self
	{
		$this->data[] = $data;
		$this->sync();
		return $this;
	}

	/**
	 * Insert row at specific index
	 */
	public function insertRow(int $index, array $data = []): self
	{
		array_splice($this->data, $index, 0, [$data]);
		$this->sync();
		return $this;
	}

	/**
	 * Update entire row (merge with existing)
	 */
	public function updateRow(int $index, array $data): self
	{
		$this->data[$index] = array_merge($this->data[$index] ?? [], $data);
		$this->sync();
		return $this;
	}

	/**
	 * Replace entire row
	 */
	public function replaceRow(int $index, array $data): self
	{
		$this->data[$index] = $data;
		$this->sync();
		return $this;
	}

	/**
	 * Remove a row
	 */
	public function removeRow(int $index): self
	{
		unset($this->data[$index]);
		$this->data = array_values($this->data); // Re-index
		$this->sync();
		return $this;
	}

	/**
	 * Remove last row
	 */
	public function pop(): self
	{
		array_pop($this->data);
		$this->sync();
		return $this;
	}

	/**
	 * Remove first row
	 */
	public function shift(): self
	{
		array_shift($this->data);
		$this->sync();
		return $this;
	}

	/**
	 * Clear all rows
	 */
	public function clear(): self
	{
		$this->data = [];
		$this->sync();
		return $this;
	}

	/**
	 * Reorder rows
	 */
	public function reorder(array $newOrder): self
	{
		$reordered = [];
		foreach ($newOrder as $index) {
			if (isset($this->data[$index])) {
				$reordered[] = $this->data[$index];
			}
		}
		$this->data = $reordered;
		$this->sync();
		return $this;
	}

	/**
	 * Move row to new position
	 */
	public function moveRow(int $from, int $to): self
	{
		if (!isset($this->data[$from])) {
			return $this;
		}

		$row = $this->data[$from];
		unset($this->data[$from]);
		$this->data = array_values($this->data);
		array_splice($this->data, $to, 0, [$row]);
		$this->sync();

		return $this;
	}

	// ─────────────────────────────────────────────────────────────
	// Query Operations
	// ─────────────────────────────────────────────────────────────

	/**
	 * Find rows where field equals value
	 */
	public function where(string $field, mixed $value): array
	{
		return array_filter($this->data, fn($row) => ($row[$field] ?? null) === $value);
	}

	/**
	 * Find first row where field equals value
	 */
	public function firstWhere(string $field, mixed $value): ?array
	{
		foreach ($this->data as $row) {
			if (($row[$field] ?? null) === $value) {
				return $row;
			}
		}
		return null;
	}

	/**
	 * Find row index where field equals value
	 */
	public function findIndex(string $field, mixed $value): ?int
	{
		foreach ($this->data as $index => $row) {
			if (($row[$field] ?? null) === $value) {
				return $index;
			}
		}
		return null;
	}

	/**
	 * Filter rows by callback
	 */
	public function filter(callable $callback): array
	{
		return array_filter($this->data, $callback);
	}

	/**
	 * Map rows through callback
	 */
	public function map(callable $callback): array
	{
		return array_map($callback, $this->data);
	}

	/**
	 * Pluck single field from all rows
	 */
	public function pluck(string $field): array
	{
		return array_column($this->data, $field);
	}

	/**
	 * Sort rows by field
	 */
	public function sortBy(string $field, string $direction = 'asc'): self
	{
		usort($this->data, function($a, $b) use ($field, $direction) {
			$aVal = $a[$field] ?? null;
			$bVal = $b[$field] ?? null;

			$result = $aVal <=> $bVal;
			return $direction === 'desc' ? -$result : $result;
		});

		$this->sync();
		return $this;
	}

	// ─────────────────────────────────────────────────────────────
	// Bulk Operations
	// ─────────────────────────────────────────────────────────────

	/**
	 * Replace all rows
	 */
	public function setAll(array $rows): self
	{
		$this->data = $rows;
		$this->sync();
		return $this;
	}

	/**
	 * Append multiple rows
	 */
	public function addRows(array $rows): self
	{
		foreach ($rows as $row) {
			$this->data[] = $row;
		}
		$this->sync();
		return $this;
	}

	/**
	 * Update field in all rows
	 */
	public function setFieldAll(string $field, mixed $value): self
	{
		foreach ($this->data as $index => $row) {
			$this->data[$index][$field] = $value;
		}
		$this->sync();
		return $this;
	}

	/**
	 * Remove field from all rows
	 */
	public function removeFieldAll(string $field): self
	{
		foreach ($this->data as $index => $row) {
			unset($this->data[$index][$field]);
		}
		$this->sync();
		return $this;
	}

	// ─────────────────────────────────────────────────────────────
	// Internal
	// ─────────────────────────────────────────────────────────────

	/**
	 * Sync data back to Meta instance
	 */
	protected function sync(): void
	{
		$this->meta->set($this->name, $this->data);
	}

	/**
	 * Get field config for subfield
	 */
	public function fieldConfig(string $field): ?array
	{
		return $this->config['fields'][$field] ?? null;
	}

	/**
	 * Get row label field name
	 */
	public function rowLabelField(): ?string
	{
		return $this->config['row_label'] ?? null;
	}
}