<?php
/**
 * Database connection and helper class for Post-ERG thesis database
 */
class Database {
    private $pdo;
    private $dbPath;

    /**
     * Constructor - establishes database connection
     * @param string $dbPath Path to SQLite database file
     */
    public function __construct($dbPath = null) {
        if ($dbPath === null) {
            // Check for test database first (for local development)
            $testDb = __DIR__ . '/test.db';
            if (file_exists($testDb)) {
                $this->dbPath = $testDb;
            } else {
                // Default to parent directory's db folder (production)
                $this->dbPath = __DIR__ . '/../db/posterg.db';
            }
        } else {
            $this->dbPath = $dbPath;
        }

        try {
            $this->pdo = new PDO('sqlite:' . $this->dbPath);
            $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $this->pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);

            // Enable foreign key constraints
            $this->pdo->exec('PRAGMA foreign_keys = ON');
        } catch (PDOException $e) {
            error_log("Database connection failed: " . $e->getMessage());
            throw new Exception("Impossible de se connecter à la base de données.");
        }
    }

    /**
     * Get PDO instance for direct queries if needed
     * @return PDO
     */
    public function getPDO() {
        return $this->pdo;
    }

    /**
     * Begin a transaction
     */
    public function beginTransaction() {
        return $this->pdo->beginTransaction();
    }

    /**
     * Commit a transaction
     */
    public function commit() {
        return $this->pdo->commit();
    }

    /**
     * Rollback a transaction
     */
    public function rollback() {
        return $this->pdo->rollback();
    }

    /**
     * Find or create an author
     * @param string $name Author name
     * @param string $email Author email (optional)
     * @return int Author ID
     */
    public function findOrCreateAuthor($name, $email = null) {
        // Try to find existing author by name
        $stmt = $this->pdo->prepare("SELECT id FROM authors WHERE name = ?");
        $stmt->execute([$name]);
        $author = $stmt->fetch();

        if ($author) {
            // Update email if provided and different
            if ($email && $email !== '') {
                $updateStmt = $this->pdo->prepare("UPDATE authors SET email = ? WHERE id = ?");
                $updateStmt->execute([$email, $author['id']]);
            }
            return $author['id'];
        }

        // Create new author
        $stmt = $this->pdo->prepare("INSERT INTO authors (name, email) VALUES (?, ?)");
        $stmt->execute([$name, $email]);
        return $this->pdo->lastInsertId();
    }

    /**
     * Find or create a supervisor
     * @param string $name Supervisor name
     * @return int Supervisor ID
     */
    public function findOrCreateSupervisor($name) {
        // Try to find existing supervisor
        $stmt = $this->pdo->prepare("SELECT id FROM supervisors WHERE name = ?");
        $stmt->execute([$name]);
        $supervisor = $stmt->fetch();

        if ($supervisor) {
            return $supervisor['id'];
        }

        // Create new supervisor
        $stmt = $this->pdo->prepare("INSERT INTO supervisors (name) VALUES (?)");
        $stmt->execute([$name]);
        return $this->pdo->lastInsertId();
    }

    /**
     * Find or create a keyword
     * @param string $keyword Keyword text
     * @return int Keyword ID
     */
    public function findOrCreateKeyword($keyword) {
        $keyword = trim($keyword);
        if (empty($keyword)) {
            return null;
        }

        // Try to find existing keyword
        $stmt = $this->pdo->prepare("SELECT id FROM keywords WHERE keyword = ?");
        $stmt->execute([$keyword]);
        $kw = $stmt->fetch();

        if ($kw) {
            return $kw['id'];
        }

        // Create new keyword
        $stmt = $this->pdo->prepare("INSERT INTO keywords (keyword) VALUES (?)");
        $stmt->execute([$keyword]);
        return $this->pdo->lastInsertId();
    }

    /**
     * Get orientation ID by name
     * @param string $name Orientation name
     * @return int|null Orientation ID or null if not found
     */
    public function getOrientationId($name) {
        $stmt = $this->pdo->prepare("SELECT id FROM orientations WHERE name = ?");
        $stmt->execute([$name]);
        $result = $stmt->fetch();
        return $result ? $result['id'] : null;
    }

    /**
     * Get AP program ID by name
     * @param string $name AP program name
     * @return int|null AP program ID or null if not found
     */
    public function getAPProgramId($name) {
        $stmt = $this->pdo->prepare("SELECT id FROM ap_programs WHERE name = ?");
        $stmt->execute([$name]);
        $result = $stmt->fetch();
        return $result ? $result['id'] : null;
    }

    /**
     * Get finality type ID by name
     * @param string $name Finality type name
     * @return int|null Finality type ID or null if not found
     */
    public function getFinalityId($name) {
        $stmt = $this->pdo->prepare("SELECT id FROM finality_types WHERE name = ?");
        $stmt->execute([$name]);
        $result = $stmt->fetch();
        return $result ? $result['id'] : null;
    }

    /**
     * Get language ID by name
     * @param string $name Language name
     * @return int|null Language ID or null if not found
     */
    public function getLanguageId($name) {
        $stmt = $this->pdo->prepare("SELECT id FROM languages WHERE name = ?");
        $stmt->execute([$name]);
        $result = $stmt->fetch();
        return $result ? $result['id'] : null;
    }

    /**
     * Get format type ID by name
     * @param string $name Format type name
     * @return int|null Format type ID or null if not found
     */
    public function getFormatId($name) {
        $stmt = $this->pdo->prepare("SELECT id FROM format_types WHERE name = ?");
        $stmt->execute([$name]);
        $result = $stmt->fetch();
        return $result ? $result['id'] : null;
    }

    /**
     * Get all orientations
     * @return array Array of orientations
     */
    public function getAllOrientations() {
        $stmt = $this->pdo->query("SELECT id, name FROM orientations ORDER BY name");
        return $stmt->fetchAll();
    }

    /**
     * Get all AP programs
     * @return array Array of AP programs
     */
    public function getAllAPPrograms() {
        $stmt = $this->pdo->query("SELECT id, name, code FROM ap_programs ORDER BY name");
        return $stmt->fetchAll();
    }

    /**
     * Get all finality types
     * @return array Array of finality types
     */
    public function getAllFinalityTypes() {
        $stmt = $this->pdo->query("SELECT id, name FROM finality_types ORDER BY name");
        return $stmt->fetchAll();
    }

    /**
     * Get all languages
     * @return array Array of languages
     */
    public function getAllLanguages() {
        $stmt = $this->pdo->query("SELECT id, name FROM languages ORDER BY name");
        return $stmt->fetchAll();
    }

    /**
     * Get all format types
     * @return array Array of format types
     */
    public function getAllFormatTypes() {
        $stmt = $this->pdo->query("SELECT id, name FROM format_types ORDER BY name");
        return $stmt->fetchAll();
    }

    /**
     * Get thesis by ID
     * @param int $id Thesis ID
     * @return array|null Thesis data or null if not found
     */
    public function getThesis($id) {
        $stmt = $this->pdo->prepare("SELECT * FROM v_theses_full WHERE id = ?");
        $stmt->execute([$id]);
        return $stmt->fetch();
    }

    /**
     * Insert a thesis file record
     * @param int $thesisId Thesis ID
     * @param string $fileType File type ('main', 'annex', 'written_part', 'other')
     * @param string $filePath Server path to file
     * @param string $fileName Original filename
     * @param int $fileSize File size in bytes
     * @param string $mimeType MIME type
     * @return int File ID
     */
    public function insertThesisFile($thesisId, $fileType, $filePath, $fileName, $fileSize, $mimeType) {
        $stmt = $this->pdo->prepare("
            INSERT INTO thesis_files (thesis_id, file_type, file_path, file_name, file_size, mime_type)
            VALUES (?, ?, ?, ?, ?, ?)
        ");
        $stmt->execute([$thesisId, $fileType, $filePath, $fileName, $fileSize, $mimeType]);
        return $this->pdo->lastInsertId();
    }
}