<?php

require_once 'engine/sphinx.php';

const WFF_ARCHIVE_SPHINX_RTINDEX = 'wff_collection';
const MDF_ARCHIVE_SPHINX_RTINDEX = 'mdf_archive';
//const BACONIANA_ARCHIVE_SPHINX_RTINDEX = 'baconiana_archive';

enum FilesCollection: string {
    case WilliamFriedman = 'wff';
    case MercureDeFrance = 'mdf';
    case Baconiana = 'baconiana';

    public function isSearchSupported(): bool {
        return $this == FilesCollection::WilliamFriedman || $this == FilesCollection::MercureDeFrance;
    }
}

enum FilesItemType: string {
    case FILE = 'file';
    case FOLDER = 'folder';
}

enum BookFileType: string {
    case NONE = 'none';
    case BOOK = 'book';
    case ARTICLE = 'article';
}

enum BookCategory: string {
    case BOOKS = 'books';
    case MISC = 'misc';
}

interface FilesItemInterface {
    public function getId(): string;
    public function isFolder(): bool;
    public function isFile(): bool;
    public function getUrl(): string;
    public function getSize(): ?int;
    public function getTitle(): string;
    public function getTitleHtml(): ?string;
    public function getMeta(?string $hl_matched = null): array;
    public function isAvailable(): bool;
    public function isTargetBlank(): bool;
    public function getSubtitle(): ?string;
}

trait FilesItemTypeTrait {
    public FilesItemType $type;
    public function isFolder(): bool { return $this->type == FilesItemType::FOLDER; }
    public function isFile(): bool { return $this->type == FilesItemType::FILE; }
}

trait FilesItemSizeTrait {
    public int $size;
    public function getSize(): ?int { return $this->isFile() ? $this->size : null; }
}

class CollectionItem implements FilesItemInterface {

    public function __construct(
        protected FilesCollection $collection
    ) {}

    public function getTitleHtml(): ?string { return null; }
    public function getId(): string { return $this->collection->value; }
    public function isFolder(): bool { return true; }
    public function isFile(): bool { return false; }
    public function isAvailable(): bool { return true; }
    public function getUrl(): string {
        global $config;
        switch ($this->collection) {
            case FilesCollection::Baconiana:
                return 'https://'.$config['files_domain'].'/Baconiana/';
            default:
                return '/files/'.$this->collection->value.'/';
        }
    }
    public function getSize(): ?int { return null; }
    public function getTitle(): string { return lang("files_{$this->collection->value}_collection"); }
    public function getMeta(?string $hl_matched = null): array { return []; }
    public function isTargetBlank(): bool { return $this->collection === FilesCollection::Baconiana; }
    public function getSubtitle(): ?string { return null; }
}

class WFFCollectionItem extends model implements FilesItemInterface {

    const DB_TABLE = 'wff_collection';

    use FilesItemTypeTrait;
    use FilesItemSizeTrait;

    public int $id;
    public int $parentId;
    public string $title;
    public string $documentId;
    public string $path;
    public int $filesCount;

    public function getTitleHtml(): ?string { return null; }
    public function getId(): string { return (string)$this->id; }
    public function isAvailable(): bool { return true; }
    public function getTitle(): string { return $this->title; }
    public function getDocumentId(): string { return $this->isFolder() ? str_replace('_', ' ', basename($this->path)) : $this->documentId; }
    public function isTargetBlank(): bool { return $this->isFile(); }
    public function getSubtitle(): ?string { return null; }

    public function getUrl(): string {
        global $config;
        return $this->isFolder()
            ? "/files/wff/{$this->id}/"
            : "https://{$config['files_domain']}/NSA Friedman Documents/{$this->path}";
    }

    public function getMeta(?string $hl_matched = null): array {
        if ($this->isFolder()) {
            if (!$this->parentId)
                return [];
            return [
                'items' => [
                    hl_matched($this->getDocumentId(), $hl_matched),
                    lang_num('files_count', $this->filesCount)
                ]
            ];
        }
        return [
            'inline' => false,
            'items' => [
                hl_matched('Document '.$this->documentId),
                sizeString($this->size),
                'PDF'
            ]
        ];
    }

}

class MDFCollectionItem extends model implements FilesItemInterface {

    const DB_TABLE = 'mdf_collection';

    use FilesItemTypeTrait;
    use FilesItemSizeTrait;

    public int $id;
    public int $issue;
    public string $path;
    public string $date;
    public int $volume;
    public int $pageFrom;
    public int $pageTo;
    public int $pdfPages;
    public int $size;

    public function isAvailable(): bool { return true; }

    public function getTitleHtml(): ?string { return null; }

    public function getTitle(): string {
        return "№{$this->issue}, {$this->getHumanFriendlyDate()}";
    }

    public function getHumanFriendlyDate(): string {
        $dt = new DateTime($this->date);
        return $dt->format('j M Y');
    }

    public function isTargetBlank(): bool { return true; }
    public function getId(): string { return $this->id; }
    public function getUrl(): string {
        global $config;
        return 'https://'.$config['files_domain'].'/Mercure-de-France-OCR/'.$this->path;
    }

    public function getMeta(?string $hl_matched = null): array {
        return [
            'inline' => true,
            'items' => [
                'Vol. '.$this->getRomanVolume(),
                'pp. '.$this->pageFrom.'-'.$this->pageTo,
                sizeString($this->size),
                'PDF'
            ]
        ];
    }

    public function getRomanVolume(): string {
        return _arabic_to_roman($this->volume);
    }

    public function getSubtitle(): ?string {
        return null;
        //return 'Vol. '.$this->getRomanVolume().', pp. '.$this->pageFrom.'-'.$this->pageTo;
    }
}

class BookItem extends model implements FilesItemInterface {

    const DB_TABLE = 'books';

    public int $id;
    public int $parentId;
    public string $author;
    public string $title;
    public int $year;
    public int $size;
    public FilesItemType $type;
    public BookFileType $fileType;
    public string $path;
    public bool $external;

    use FilesItemSizeTrait;
    use FilesItemTypeTrait;

    public function getId(): string {
        return $this->id;
    }

    public function getUrl(): string {
        if ($this->isFolder() && !$this->external)
            return '/files/'.$this->id.'/';
        global $config;
        $buf = 'https://'.$config['files_domain'];
        if (!str_starts_with($this->path, '/'))
            $buf .= '/';
        $buf .= $this->path;
        return $buf;
    }

    public function getTitleHtml(): ?string {
        if ($this->isFolder() || !$this->author)
            return null;
        $buf = '<b class="is-author">'.htmlescape($this->author).'</b><span class="is-title">';
        if (!str_ends_with($this->author, '.'))
            $buf .= '.';
        $buf .= ' '.htmlescape($this->title).'</span>';
        return $buf;
    }

    public function getTitle(): string {
        return $this->title;
    }

    public function getMeta(?string $hl_matched = null): array {
        if ($this->isFolder())
            return [];

        $items = [
            sizeString($this->size),
            strtoupper($this->getExtension())
        ];

        return [
            'inline' => false,
            'items' => $items
        ];
    }

    protected function getExtension(): string {
        return extension(basename($this->path));
    }

    public function isAvailable(): bool {
        return true;
    }

    public function isTargetBlank(): bool {
        return $this->isFile() || $this->external;
    }

    public function getSubtitle(): ?string {
        if (!$this->year)
            return null;
        return '('.$this->year.')';
    }
}

/**
 * @param int $folder_id
 * @param bool $with_parents
 * @return WFFCollectionItem|WFFCollectionItem[]|null
 */
function wff_get_folder(int $folder_id, bool $with_parents = false): WFFCollectionItem|array|null {
    $db = DB();
    $q = $db->query("SELECT * FROM wff_collection WHERE id=?", $folder_id);
    if (!$db->numRows($q))
        return null;
    $item = new WFFCollectionItem($db->fetch($q));
    if (!$item->isFolder())
        return null;
    if ($with_parents) {
        $items = [$item];
        if ($item->parentId) {
            $parents = wff_get_folder($item->parentId, true);
            if ($parents !== null)
                $items = array_merge($items, $parents);
        }
        return $items;
    }
    return $item;
}

/**
 * @param int|int[]|null $parent_id
 * @return array
 */
function wff_get(int|array|null $parent_id = null) {
    $db = DB();

    $where = [];
    $args = [];

    if (!is_null($parent_id)) {
        if (is_int($parent_id)) {
            $where[] = "parent_id=?";
            $args[] = $parent_id;
        } else {
            $where[] = "parent_id IN (".implode(", ", $parent_id).")";
        }
    }
    $sql = "SELECT * FROM wff_collection";
    if (!empty($where))
        $sql .= " WHERE ".implode(" AND ", $where);
    $sql .= " ORDER BY title";
    $q = $db->query($sql, ...$args);

    return array_map('WFFCollectionItem::create_instance', $db->fetchAll($q));
}

/**
 * @param int[] $ids
 * @return WFFCollectionItem[]
 */
function wff_get_by_id(array $ids): array {
    $db = DB();
    $q = $db->query("SELECT * FROM wff_collection WHERE id IN (".implode(',', $ids).")");
    return array_map('WFFCollectionItem::create_instance', $db->fetchAll($q));
}

function wff_search(string $q, int $offset = 0, int $count = 0): array {
    $query_filtered = sphinx_mkquery($q);

    $cl = sphinx_client();
    $cl->setLimits($offset, $count);
    $cl->setMatchMode(Sphinx\SphinxClient::SPH_MATCH_EXTENDED);
    $cl->setFieldWeights([
        'title' => 50,
        'document_id' => 60,
    ]);

    $cl->setRankingMode(Sphinx\SphinxClient::SPH_RANK_PROXIMITY_BM25);
    $cl->setSortMode(Sphinx\SphinxClient::SPH_SORT_EXTENDED, '@relevance DESC, is_folder DESC');

    // run search
    $final_query = "$query_filtered";
    $result = $cl->query($final_query, WFF_ARCHIVE_SPHINX_RTINDEX);
    $error = $cl->getLastError();
    $warning = $cl->getLastWarning();
    if ($error)
        logError(__FUNCTION__, $error);
    if ($warning)
        logWarning(__FUNCTION__, $warning);
    if ($result === false)
        return ['count' => 0, 'items' => []];

    $total_found = (int)$result['total_found'];

    $items = [];
    if (!empty($result['matches']))
        $items = wff_get_by_id(array_keys($result['matches']));

    return ['count' => $total_found, 'items' => $items];
}

function wff_reindex(): void {
    sphinx_execute("TRUNCATE RTINDEX ".WFF_ARCHIVE_SPHINX_RTINDEX);
    $db = DB();
    $q = $db->query("SELECT * FROM wff_collection");
    while ($row = $db->fetch($q)) {
        $item = new WFFCollectionItem($row);
        if ($item->isFile()) {
            $txt = file_get_contents('/home/user/nsa/txt/'.str_replace('.pdf', '.txt', basename($item->path)));
        } else {
            $txt = '';
        }
        sphinx_execute("INSERT INTO ".WFF_ARCHIVE_SPHINX_RTINDEX." (id, document_id, title, text, is_folder, parent_id) VALUES (?, ?, ?, ?, ?, ?)",
            $item->id, $item->getDocumentId(), $item->title, $txt, (int)$item->isFolder(), $item->parentId);
    }
}

function mdf_get_text_excerpts(array $ids, array $keywords, int $before = 50, int $after = 40): array {
    return _get_text_excerpts('mdf_texts', 'mdf_id', $ids, $keywords, $before, $after);
}

function wff_get_text_excerpts(array $ids, array $keywords, int $before = 50, int $after = 40): array {
    return _get_text_excerpts('wff_texts', 'wff_id', $ids, $keywords, $before, $after);
}

/**
 * @param string $table
 * @param string $field_id
 * @param int[] $ids
 * @param string[] $keywords  Must already be lower-cased
 * @param int $before
 * @param int $after
 * @return array
 */
function _get_text_excerpts(string $table, string $field_id, array $ids, array $keywords, int $before, int $after) {
    $results = [];
    foreach ($ids as $id)
        $results[$id] = null;

    $db = DB();

    $dynamic_sql_parts = [];
    $combined_parts = [];
    foreach ($keywords as $keyword) {
        $part = "LOCATE('".$db->escape($keyword)."', text)";
        $dynamic_sql_parts[] = $part;
    }
    if (count($dynamic_sql_parts) > 1) {
        foreach ($dynamic_sql_parts as $part)
            $combined_parts[] = "IF({$part} > 0, {$part}, CHAR_LENGTH(text) + 1)";
        $combined_parts = implode(', ', $combined_parts);
        $combined_parts = 'LEAST('.$combined_parts.')';
    } else {
        $combined_parts = "IF({$dynamic_sql_parts[0]} > 0, {$dynamic_sql_parts[0]}, CHAR_LENGTH(text) + 1)";
    }

    $total = $before + $after;
    $sql = "SELECT
        {$field_id} AS id,
        GREATEST(
            1,
            {$combined_parts} - {$before}
        ) AS excerpt_start_index,
        SUBSTRING(
            text,
            GREATEST(
                1,
                {$combined_parts} - {$before}
            ),
            LEAST(
                CHAR_LENGTH(text),
                {$total} + {$combined_parts} - GREATEST(1, {$combined_parts} - {$before})
            )
        ) AS excerpt
    FROM
        {$table}
    WHERE
        {$field_id} IN (".implode(',', $ids).")";

    $q = $db->query($sql);
    while ($row = $db->fetch($q)) {
        $results[$row['id']] = [
            'excerpt' => preg_replace('/\s+/', ' ', $row['excerpt']),
            'index' => (int)$row['excerpt_start_index']
        ];
    }

    return $results;
}

/**
 * @return MDFCollectionItem[]
 */
function mdf_get(): array {
    $db = DB();
    $q = $db->query("SELECT * FROM mdf_collection ORDER BY `date`");
    return array_map('MDFCollectionItem::create_instance', $db->fetchAll($q));
}

/**
 * @param int[] $ids
 * @return MDFCollectionItem[]
 */
function mdf_get_by_id(array $ids): array {
    $db = DB();
    $q = $db->query("SELECT * FROM mdf_collection WHERE id IN (".implode(',', $ids).")");
    return array_map('MDFCollectionItem::create_instance', $db->fetchAll($q));
}

function mdf_search(string $q, int $offset = 0, int $count = 0): array {
    $query_filtered = sphinx_mkquery($q);

    $cl = sphinx_client();
    $cl->setLimits($offset, $count);
    $cl->setMatchMode(Sphinx\SphinxClient::SPH_MATCH_EXTENDED);
    $cl->setFieldWeights([
        'date' => 10,
        'issue' => 9,
        'text' => 8
    ]);

    $cl->setRankingMode(Sphinx\SphinxClient::SPH_RANK_PROXIMITY_BM25);
    $cl->setSortMode(Sphinx\SphinxClient::SPH_SORT_RELEVANCE);

    // run search
    $final_query = "$query_filtered";
    $result = $cl->query($final_query, MDF_ARCHIVE_SPHINX_RTINDEX);
    $error = $cl->getLastError();
    $warning = $cl->getLastWarning();
    if ($error)
        logError(__FUNCTION__, $error);
    if ($warning)
        logWarning(__FUNCTION__, $warning);
    if ($result === false)
        return ['count' => 0, 'items' => []];

    $total_found = (int)$result['total_found'];

    $items = [];
    if (!empty($result['matches']))
        $items = mdf_get_by_id(array_keys($result['matches']));

    return ['count' => $total_found, 'items' => $items];
}

function mdf_reindex(): void {
    sphinx_execute("TRUNCATE RTINDEX ".MDF_ARCHIVE_SPHINX_RTINDEX);
    $db = DB();
    $mdf = mdf_get();
    foreach ($mdf as $item) {
        $text = $db->result($db->query("SELECT text FROM mdf_texts WHERE mdf_id=?", $item->id));
        sphinx_execute("INSERT INTO ".MDF_ARCHIVE_SPHINX_RTINDEX." (id, volume, issue, date, text) VALUES (?, ?, ?, ?, ?)",
            $item->id, $item->volume, (string)$item->issue, $item->getHumanFriendlyDate(), $text);
    }
}

/**
 * @return BookItem[]
 */
function books_get(int $parent_id = 0,
                   BookCategory $category = BookCategory::BOOKS): array {
    $db = DB();

    if ($category == BookCategory::BOOKS) {
        $order_by = "type, ".($parent_id != 0 ? 'year, ': '')."author, title";
    }
    else
        $order_by = "type, title";

    $q = $db->query("SELECT * FROM books WHERE category=? AND parent_id=? ORDER BY $order_by",
        $category->value, $parent_id);
    return array_map('BookItem::create_instance', $db->fetchAll($q));
}

function books_get_folder(int $id): ?BookItem {
    $db = DB();
    $q = $db->query("SELECT * FROM books WHERE id=?", $id);
    if (!$db->numRows($q))
        return null;
    $item = new BookItem($db->fetch($q));
    if (!$item->isFolder())
        return null;
    return $item;
}

function _arabic_to_roman($number) {
    $map = [
        1000 => 'M',
        900 => 'CM',
        500 => 'D',
        400 => 'CD',
        100 => 'C',
        90 => 'XC',
        50 => 'L',
        40 => 'XL',
        10 => 'X',
        9 => 'IX',
        5 => 'V',
        4 => 'IV',
        1 => 'I',
    ];
    $result = '';

    foreach ($map as $arabic => $roman) {
        while ($number >= $arabic) {
            $result .= $roman;
            $number -= $arabic;
        }
    }

    return $result;
}