<?php

declare(strict_types=1);

final class Migrations
{
    public static function run(string $migrationsDir): void
    {
        $db = DB::pdo();
        $db->exec('CREATE TABLE IF NOT EXISTS _migrations (name TEXT PRIMARY KEY, applied_at TEXT NOT NULL);');

        $files = glob(rtrim($migrationsDir, '/') . '/*.sql') ?: [];
        sort($files);

        foreach ($files as $file) {
            $name = basename($file);

            $stmt = $db->prepare('SELECT 1 FROM _migrations WHERE name = :n');
            $stmt->execute([':n' => $name]);
            if ($stmt->fetchColumn()) {
                continue;
            }

            $sql = file_get_contents($file);
            if ($sql === false) {
                throw new RuntimeException("Cannot read migration: $name");
            }

            // Les toutes premières installations utilisaient déjà deleted_at avant
            // que cette colonne ne soit correctement inscrite dans une migration.
            if ($name === '025_animal_archive_and_trash.sql') {
                $columns = array_column($db->query('PRAGMA table_info(animals)')->fetchAll(PDO::FETCH_ASSOC), 'name');
                if (!in_array('deleted_at', $columns, true)) {
                    $db->exec('ALTER TABLE animals ADD COLUMN deleted_at TEXT');
                }
            }

            // Répare les bases créées par une candidate rc.3 incomplète, dans
            // laquelle les médias privés étaient utilisés avant d'être migrés.
            if ($name === '089_media_schema_repair.sql') {
                $columns = array_column(
                    $db->query('PRAGMA table_info(animal_photos)')->fetchAll(PDO::FETCH_ASSOC),
                    'name',
                );
                if (!in_array('is_public', $columns, true)) {
                    $db->exec('ALTER TABLE animal_photos ADD COLUMN is_public INTEGER NOT NULL DEFAULT 1');
                }
            }

            // Les anciennes bases possédaient déjà le nouvel historique alors
            // que les installations neuves recevaient encore son premier schéma.
            if ($name === '090_medication_administration_routes.sql') {
                $columns = array_column(
                    $db->query('PRAGMA table_info(animal_history)')->fetchAll(PDO::FETCH_ASSOC),
                    'name',
                );
                if (!in_array('type', $columns, true)) {
                    $db->exec("ALTER TABLE animal_history ADD COLUMN type TEXT NOT NULL DEFAULT 'history'");
                }
                if (!in_array('label', $columns, true)) {
                    $db->exec("ALTER TABLE animal_history ADD COLUMN label TEXT NOT NULL DEFAULT ''");
                }
                if (!in_array('details', $columns, true)) {
                    $db->exec('ALTER TABLE animal_history ADD COLUMN details TEXT');
                }
            }

            // Deux anciens schémas de l’historique ont circulé : l’un avec
            // action/field/values, l’autre avec type/label/details. Le code
            // courant accepte les données des deux et a besoin de leur union.
            if ($name === '096_animal_history_compatibility.sql') {
                $columns = array_column(
                    $db->query('PRAGMA table_info(animal_history)')->fetchAll(PDO::FETCH_ASSOC),
                    'name',
                );
                $definitions = [
                    'action' => "TEXT NOT NULL DEFAULT 'history'",
                    'field' => 'TEXT',
                    'old_value' => 'TEXT',
                    'new_value' => 'TEXT',
                    'meta' => 'TEXT',
                    'type' => "TEXT NOT NULL DEFAULT 'history'",
                    'label' => "TEXT NOT NULL DEFAULT ''",
                    'details' => 'TEXT',
                    'user_id' => 'INTEGER',
                ];
                foreach ($definitions as $column => $definition) {
                    if (!in_array($column, $columns, true)) {
                        $db->exec("ALTER TABLE animal_history ADD COLUMN $column $definition");
                    }
                }
            }

            $relaxesForeignKeys = in_array(
                $name,
                ['093_room_rules_and_care_periods.sql', '097_remove_legacy_room_constraint.sql'],
                true,
            );
            if ($relaxesForeignKeys) {
                $db->exec('PRAGMA foreign_keys = OFF');
            }
            $db->beginTransaction();
            try {
                if ($name === '097_remove_legacy_room_constraint.sql') {
                    self::modernizeAnimalConstraints($db);
                } else {
                    $db->exec($sql);
                }
                $ins = $db->prepare("INSERT INTO _migrations(name, applied_at) VALUES(:n, datetime('now'))");
                $ins->execute([':n' => $name]);
                if ($relaxesForeignKeys && $db->query('PRAGMA foreign_key_check')->fetchColumn() !== false) {
                    throw new RuntimeException('Foreign key check failed after room migration');
                }
                $db->commit();
                if ($relaxesForeignKeys) {
                    $db->exec('PRAGMA foreign_keys = ON');
                }
            } catch (Throwable $e) {
                $db->rollBack();
                if ($relaxesForeignKeys) {
                    $db->exec('PRAGMA foreign_keys = ON');
                }
                throw new RuntimeException('Migration ' . $name . ' : ' . $e->getMessage(), 0, $e);
            }
        }
    }

    private static function modernizeAnimalConstraints(PDO $db): void
    {
        $createSql = (string) $db
            ->query("SELECT sql FROM sqlite_master WHERE type='table' AND name='animals'")
            ->fetchColumn();
        $constraint = "/refuge_room\\s+TEXT\\s+CHECK\\s*\\(\\s*refuge_room\\s+IN\\s*\\(\\s*'silver'\\s*,\\s*'twix'\\s*\\)\\s+OR\\s+refuge_room\\s+IS\\s+NULL\\s*\\)/i";
        $registrationConstraint = "/identification_registration_status\\s+TEXT\\s+NOT\\s+NULL\\s+DEFAULT\\s+'unknown'\\s+CHECK\\s*\\(\\s*identification_registration_status\\s+IN\\s*\\(\\s*'unknown'\\s*,\\s*'pending'\\s*,\\s*'registered'\\s*\\)\\s*\\)/i";
        if (
            $createSql === ''
            || (!preg_match($constraint, $createSql) && !preg_match($registrationConstraint, $createSql))
        ) {
            return;
        }

        $newSql = preg_replace(
            '/^CREATE TABLE\\s+(?:IF NOT EXISTS\\s+)?["`\[]?animals["`\]]?/i',
            'CREATE TABLE animals_room_unrestricted',
            $createSql,
            1,
        );
        $newSql = preg_replace($constraint, 'refuge_room TEXT', (string) $newSql, 1);
        $newSql = preg_replace(
            $registrationConstraint,
            "identification_registration_status TEXT NOT NULL DEFAULT 'unknown' " .
                "CHECK(identification_registration_status IN ('unknown','registered','change_pending','owner_changed','pending'))",
            (string) $newSql,
            1,
        );
        if (!$newSql || preg_match($constraint, $newSql)) {
            throw new RuntimeException('Unable to remove the legacy shelter-room constraint.');
        }

        $objects = $db
            ->query("SELECT sql FROM sqlite_master WHERE tbl_name='animals' AND type IN ('index','trigger') AND sql IS NOT NULL")
            ->fetchAll(PDO::FETCH_COLUMN);
        $views = $db
            ->query("SELECT name,sql FROM sqlite_master WHERE type='view' AND sql IS NOT NULL ORDER BY rowid")
            ->fetchAll(PDO::FETCH_ASSOC);
        $columns = array_column($db->query('PRAGMA table_info(animals)')->fetchAll(PDO::FETCH_ASSOC), 'name');
        $quotedColumns = implode(',', array_map(static fn(string $column): string => '"' . str_replace('"', '""', $column) . '"', $columns));

        foreach ($views as $view) {
            $viewName = '"' . str_replace('"', '""', (string) $view['name']) . '"';
            $db->exec('DROP VIEW ' . $viewName);
        }
        $db->exec($newSql);
        $db->exec("INSERT INTO animals_room_unrestricted ($quotedColumns) SELECT $quotedColumns FROM animals");
        $db->exec("UPDATE animals_room_unrestricted SET identification_registration_status='change_pending' WHERE identification_registration_status='pending'");
        $db->exec('DROP TABLE animals');
        $db->exec('ALTER TABLE animals_room_unrestricted RENAME TO animals');
        foreach ($objects as $objectSql) {
            $db->exec((string) $objectSql);
        }
        foreach ($views as $view) {
            $db->exec((string) $view['sql']);
        }
    }
}