<?php

namespace dokuwiki\plugin\luxtools;

/**
 * Maps scratchpad aliases (used in wiki pages) to full filesystem file paths.
 *
 * Config format (one per line):
 *   /full/path/to/pad-file.txt
 *   A> padname
 *
 * The next A> line assigns an alias for the previously listed file.
 */
class ScratchpadMap
{
    /** @var array<string, array{alias:string, path:string}> */
    protected $map = [];

    /**
     * @param string $config
     */
    public function __construct($config)
    {
        $this->map = $this->parseConfig((string)$config);
    }

    /**
     * Resolve the given alias to a full file path.
     *
     * @param string $alias
     * @return string
     * @throws \Exception
     */
    public function resolve($alias)
    {
        $alias = trim((string)$alias);
        if ($alias === '') throw new \Exception('Empty alias');
        if (!isset($this->map[$alias])) {
            throw new \Exception('Unknown scratchpad alias');
        }
        return (string)$this->map[$alias]['path'];
    }

    /**
     * Return the parsed mapping.
     *
     * @return array<string, array{alias:string, path:string}>
     */
    public function getMap()
    {
        return $this->map;
    }

    /**
     * @param string $config
     * @return array<string, array{alias:string, path:string}>
     */
    protected function parseConfig($config)
    {
        $map = [];
        $lines = explode("\n", (string)$config);

        $lastFile = '';
        foreach ($lines as $line) {
            $line = trim($line);
            if ($line === '') continue;

            if (str_starts_with($line, 'A>')) {
                $alias = trim(substr($line, 2));
                if ($alias === '' || $lastFile === '') continue;
                $map[$alias] = [
                    'alias' => $alias,
                    'path' => $lastFile,
                ];
                continue;
            }

            // Treat as file path (no trailing slash enforced)
            $filePath = Path::cleanPath($line, false);
            if ($filePath === '' || str_ends_with($filePath, '/')) {
                // Ignore invalid entries; they will not be resolvable
                $lastFile = '';
                continue;
            }

            $lastFile = $filePath;
        }

        return $map;
    }
}