<?php
/**
 * CODING CONVENTION:
 * This file follows the coding convention where variable_names and function_names
 * use snake_case (underscore_wherever_possible).
 */

namespace App\RSpade\Commands\Migrate;

use Illuminate\Console\Command;
use Illuminate\Support\Facades\Artisan;
use Illuminate\Support\Facades\DB;
use Symfony\Component\Console\Output\BufferedOutput;
use Illuminate\Database\Console\Migrations\MigrateCommand;
use App\Providers\AppServiceProvider;
use App\RSpade\Core\Database\MigrationValidator;
use App\RSpade\Core\Database\SqlQueryTransformer;

/**
 * Custom migration command that runs standard migrations plus maintenance commands
 *
 * This command extends Laravel's built-in migrate command to also run additional
 * maintenance commands after migrations complete:
 *
 * 1. migrate:normalize_schema - Normalizes database schema (data types, encodings, required columns)
 * 2. migrate:regenerate_constants - Updates model constants and docblocks, exports to JavaScript
 *
 * The command preserves and displays all output from the standard migration command,
 * then runs the maintenance commands.
 *
 * This command is automatically used when running 'php artisan migrate' due to
 * a modification in the artisan script.
 */
class Maint_Migrate extends Command
{
    protected $signature = 'migrate {--force} {--seed} {--step} {--path=*} {--production : Run in production mode, skipping snapshot requirements} {--framework-only : Run only framework migrations (system/database/migrations), skip snapshot, but run normalization}';

    protected $description = 'Run migrations and maintenance commands';

    protected $flag_file = '/var/www/html/.migrating';

    public function handle()
    {
        // Enable SQL query transformation for migrations
        SqlQueryTransformer::enable();
        $this->register_query_transformer();

        // Enable full query logging to stdout for migrations
        AppServiceProvider::set_query_log_mode(AppServiceProvider::QUERY_LOG_ALL_STDOUT);

        // Ensure migrations table exists (create it if needed)
        $this->ensure_migrations_table_exists();

        // Check if we're in production mode (either via flag or environment)
        $is_production = $this->option('production') || app()->environment('production');

        // Check if we're in framework-only mode
        $is_framework_only = $this->option('framework-only');

        // Only enforce snapshot protection in development mode without --production or --framework-only flag
        $require_snapshot = !$is_production && !$is_framework_only;

        // Check for migration mode if we require snapshot
        if ($require_snapshot) {
            if (!file_exists($this->flag_file)) {
                $this->error('[ERROR] Migration mode not active!');
                $this->error('');
                $this->line('In development mode, you must create a database snapshot before running migrations.');
                $this->line('This prevents partial migrations from corrupting your database.');
                $this->info('');
                $this->line('To begin a migration session:');
                $this->line('   php artisan migrate:begin');

                return 1;
            }

            $this->info('[OK] Migration mode active - snapshot available for rollback');
            $this->info('');
        } elseif ($is_production) {
            $this->info(' Running in production mode (no snapshot protection)');
        } elseif ($is_framework_only) {
            $this->info(' Running framework-only migrations (no snapshot protection)');
        }

        $mode_desc = $is_production ? ' (production mode)' : ($is_framework_only ? ' (framework-only)' : ' with maintenance commands');
        $this->info('Running migrations' . $mode_desc . '...');

        // Get all the options
        $force = $this->option('force');
        $seed = $this->option('seed');
        $step = $this->option('step');
        $paths = $this->option('path');

        // Check if path option is used and throw exception
        if (!empty($paths)) {
            $this->error('[ERROR] Migration by path is disabled!');
            $this->error('');
            $this->line('This command enforces running all pending migrations in order.');
            $this->line('Please run migrations without the --path option:');
            $this->info('   php artisan migrate');
            $this->error('');
            $this->line('If you need to run specific migrations:');
            $this->line('   1. Place them in the standard migrations directory');
            $this->line('   2. Use migration timestamps to control execution order');
            return 1;
        }

        // Determine which migration paths to use for whitelist check
        $paths_to_check = $is_framework_only
            ? [database_path('migrations')]
            : MigrationPaths::get_all_paths();

        // Check migration whitelist
        if (!$this->checkMigrationWhitelist($paths_to_check)) {
            return 1;
        }

        // Validate migration files for Schema builder usage (only in non-production)
        if (!$is_production && !$this->_validate_schema_rules()) {
            return 1;
        }

        // Build command arguments
        $migrateArgs = [];
        if ($force) {
            $migrateArgs['--force'] = true;
        }
        if ($seed) {
            $migrateArgs['--seed'] = true;
        }
        if ($step) {
            $migrateArgs['--step'] = true;
        }

        // Run normalize_schema BEFORE migrations to fix existing tables
        // Pass --production flag to skip snapshot in both production and framework-only modes
        $requiredColumnsArgs = ($is_production || $is_framework_only) ? ['--production' => true] : [];

        $this->info("\n Pre-migration normalization (fixing existing tables)...\n");
        $normalizeExitCode = $this->call('migrate:normalize_schema', $requiredColumnsArgs);
        if ($normalizeExitCode !== 0) {
            $this->error('Pre-migration normalization failed');
            SqlQueryTransformer::disable();
            return $normalizeExitCode;
        }

        // Use a buffered output to capture migration output
        $bufferedOutput = new BufferedOutput();

        try {
            // Run the standard migrations and capture the output
            $originalSqlMode = DB::selectOne('SELECT @@sql_mode as sql_mode')->sql_mode;
            DB::statement("SET sql_mode = REPLACE(@@sql_mode, 'NO_ZERO_DATE', '');");

            // Run migrations directly via migrator to avoid recursion
            $migrator = app('migrator');
            $migrator->setOutput($bufferedOutput);

            // Use all migration paths (framework + user), or just framework if --framework-only
            $migrationPaths = $is_framework_only
                ? [database_path('migrations')]
                : MigrationPaths::get_all_paths();

            // Run migrations one-by-one with normalization after each
            $this->run_migrations_with_normalization($migrator, $migrationPaths, $step, $requiredColumnsArgs);

            $exitCode = 0;

            // Handle seeding if requested
            if ($seed) {
                $this->call('db:seed', ['--force' => $force]);
            }

            $migrationOutput = $bufferedOutput->fetch();

            // Show the output from the migration command
            $this->output->write($migrationOutput);

            DB::statement('SET sql_mode = ?', [$originalSqlMode]);

            // Check if migration failed
            if ($exitCode !== 0) {
                throw new \Exception("Migration command failed with exit code: $exitCode");
            }
        } catch (\Exception $e) {
            // Restore SQL mode
            try {
                DB::statement('SET sql_mode = ?', [$originalSqlMode]);
            } catch (\Exception $sqlEx) {
                // Ignore SQL mode restore errors
            }

            $this->error('');
            $this->error('[ERROR] Migration failed!');
            $this->error('Error: ' . $e->getMessage());

            // If in development mode with snapshot, automatically rollback
            if ($require_snapshot && file_exists($this->flag_file)) {
                $this->error('');
                $this->warn(' Automatically rolling back to snapshot due to migration failure...');
                $this->info('');

                // Call rollback command with output
                $rollback_result = Artisan::call('migrate:rollback', [], $this->output);

                if ($rollback_result === 0) {
                    $this->info('');
                    $this->info('[OK] Database rolled back successfully!');
                    $this->info('');
                    $this->warn('[WARNING]  You are still in migration mode.');
                    $this->line('Your options:');
                    $this->line('   1. Fix your migration files');
                    $this->line('   2. Run "php artisan migrate" to try again');
                    $this->line('   3. Run "php artisan migrate:commit" to exit migration mode');
                } else {
                    $this->error('[ERROR] Automatic rollback failed!');
                    $this->error('Run "php artisan migrate:rollback" manually.');
                    $this->warn('[WARNING]  The database may be in an inconsistent state!');
                }
            }
            
            // Disable query logging before returning
            AppServiceProvider::disable_query_echo();

            // Disable SQL query transformation
            SqlQueryTransformer::disable();

            return 1;
        }

        // Run normalize_schema AFTER migrations to add framework columns to new tables
        $this->info("\n Post-migration normalization (adding framework columns to new tables)...\n");

        // Switch to destructive-only query logging for normalize_schema
        AppServiceProvider::set_query_log_mode(AppServiceProvider::QUERY_LOG_DESTRUCTIVE_STDOUT);

        $normalizeExitCode = $this->call('migrate:normalize_schema', $requiredColumnsArgs);
        if ($normalizeExitCode !== 0) {
            $this->error('Post-migration normalization failed');
            return $normalizeExitCode;
        }
        
        // Run regenerate constants if not in production mode (framework-only still runs it)
        if (!$is_production) {
            // Disable query logging for regenerate_constants
            AppServiceProvider::disable_query_echo();

            $maintenanceExitCode = $this->runMaintenanceCommand('rsx:constants:regenerate');
            if ($maintenanceExitCode !== 0) {
                $this->error('Regenerate constants maintenance failed');
                return $maintenanceExitCode;
            }
        } else {
            // In production mode, check manifest consistency with database
            // Disable query logging for consistency check
            AppServiceProvider::disable_query_echo();

            $this->info("\n");
            $consistency_check_exit = $this->call('rsx:migrate:check_consistency');
            if ($consistency_check_exit !== 0) {
                $exitCode = 1;
            }
        }

        $this->info("\nAll tasks completed!");

        // Remind user to commit snapshot in development mode
        if ($require_snapshot) {
            $this->newLine();
            $this->line('Please run <info>php artisan migrate:commit</info> to finish the migration process.');
        }

        // Disable query logging
        AppServiceProvider::disable_query_echo();

        // Disable SQL query transformation
        SqlQueryTransformer::disable();

        return $exitCode;
    }

    /**
     * Register query transformation listener
     *
     * Intercepts all DB::statement() calls and transforms CREATE/ALTER statements
     * to enforce framework column type conventions.
     */
    protected function register_query_transformer(): void
    {
        // Store the original statement method
        $original_statement = \Closure::bind(function () {
            return $this->connection->statement(...func_get_args());
        }, DB::getFacadeRoot(), DB::getFacadeRoot());

        // Override DB::statement to transform queries
        DB::macro('statement', function ($query, $bindings = []) use ($original_statement) {
            // Transform the query before execution
            $transformed = SqlQueryTransformer::transform($query);

            // Call the original statement method with transformed query
            return DB::connection()->statement($transformed, $bindings);
        });
    }

    /**
     * Check if all pending migrations are whitelisted
     *
     * @param array $paths Array of migration paths to check
     */
    protected function checkMigrationWhitelist(array $paths): bool
    {
        // Load whitelists from both locations and merge them
        $whitelistPaths = [
            database_path('migrations/.migration_whitelist'),           // Framework migrations
            base_path('rsx/resource/migrations/.migration_whitelist'),  // Application migrations
        ];

        $whitelistedMigrations = [];
        $foundAtLeastOne = false;

        foreach ($whitelistPaths as $whitelistPath) {
            if (file_exists($whitelistPath)) {
                $foundAtLeastOne = true;
                $whitelist = json_decode(file_get_contents($whitelistPath), true);
                $migrations = array_keys($whitelist['migrations'] ?? []);
                $whitelistedMigrations = array_merge($whitelistedMigrations, $migrations);
            }
        }

        // If no whitelist exists yet, create one with existing migrations
        if (!$foundAtLeastOne) {
            $this->warn('[WARNING]  No migration whitelist found. Creating one with existing migrations...');
            $this->createInitialWhitelist();
            return true;
        }

        // Get all migration files from specified paths
        $migrationFiles = [];
        foreach ($paths as $path) {
            if (is_dir($path)) {
                foreach (glob($path . '/*.php') as $file) {
                    $migrationFiles[] = basename($file);
                }
            }
        }

        // Check for unauthorized migrations
        $unauthorizedMigrations = array_diff($migrationFiles, $whitelistedMigrations);

        if (!empty($unauthorizedMigrations)) {
            $this->error('[ERROR] Unauthorized migrations detected!');
            $this->error('');
            $this->line('The following migrations were not created via php artisan make:migration:');
            foreach ($unauthorizedMigrations as $migration) {
                $this->line('   • ' . $migration);
            }
            $this->error('');
            $this->warn('[WARNING]  Manually created migrations can cause timestamp conflicts and ordering issues.');
            $this->error('');
            $this->line('To fix this:');
            $this->line('1. Create a new migration using: php artisan make:migration [name]');
            $this->line('2. Copy the migration code from the unauthorized file to the new file');
            $this->line('3. Delete the unauthorized migration file');
            $this->line('4. Run migrations again');
            $this->error('');
            $this->line('This ensures proper timestamp generation and prevents LLM timestamp confusion.');

            return false;
        }

        return true;
    }

    /**
     * Create initial whitelist with existing migrations
     * Creates separate whitelist files for framework and application migrations
     */
    protected function createInitialWhitelist(): void
    {
        $whitelistLocations = [
            database_path('migrations/.migration_whitelist') => database_path('migrations'),
            base_path('rsx/resource/migrations/.migration_whitelist') => base_path('rsx/resource/migrations'),
        ];

        $totalMigrations = 0;

        foreach ($whitelistLocations as $whitelistPath => $migrationPath) {
            // Skip if migration directory doesn't exist
            if (!is_dir($migrationPath)) {
                continue;
            }

            $whitelist = [
                'description' => 'This file tracks migrations created via php artisan make:migration',
                'purpose' => 'Prevents manually created migrations from running to avoid timestamp conflicts',
                'migrations' => [],
            ];

            // Add all existing migrations from this specific path
            foreach (glob($migrationPath . '/*.php') as $file) {
                $filename = basename($file);
                $whitelist['migrations'][$filename] = [
                    'created_at' => 'pre-whitelist',
                    'created_by' => 'system',
                    'command' => 'existing migration',
                ];
            }

            // Only create whitelist if there are migrations in this location
            if (!empty($whitelist['migrations'])) {
                file_put_contents($whitelistPath, json_encode($whitelist, JSON_PRETTY_PRINT));
                $count = count($whitelist['migrations']);
                $totalMigrations += $count;
                $location = str_replace(base_path() . '/', '', dirname($whitelistPath));
                $this->info("[OK] Created whitelist in {$location} with {$count} migration(s).");
            }
        }

        if ($totalMigrations === 0) {
            $this->info('[OK] No existing migrations found. Empty whitelists created.');
        }
    }

    protected function runMaintenanceCommand($command, $arguments = [])
    {
        $this->info("\nRunning $command...");
        $output = new BufferedOutput();
        $exitCode = Artisan::call($command, $arguments, $output);
        $commandOutput = $output->fetch();

        // Only show concise output if successful
        if ($exitCode === 0) {
            $this->info("[OK] Command $command completed successfully.");
        } else {
            $this->error("[FAIL] Command $command failed with exit code $exitCode");
            $this->output->write($commandOutput);
        }

        return $exitCode;
    }

    /**
     * Validate migration files for Schema builder usage
     * Only enforced in non-production mode
     */
    protected function _validate_schema_rules(): bool
    {
        $repository = app('migration.repository');
        $pending_migrations = MigrationValidator::get_pending_migrations($repository);

        if (empty($pending_migrations)) {
            // No pending migrations to validate
            return true;
        }

        $this->info('Validating migration files for Schema builder usage...');

        $has_violations = false;

        foreach ($pending_migrations as $migration_path) {
            try {
                // Validate the migration file for Schema builder usage
                MigrationValidator::validate_migration_file($migration_path);
                $this->info("  [OK] " . basename($migration_path));
            } catch (\RuntimeException $e) {
                // MigrationValidator already printed colored error output
                $has_violations = true;
                break; // Stop at first violation
            }
        }

        if ($has_violations) {
            $this->error('');
            $this->error('Migration validation failed!');
            $this->info('');
            $this->line('Please update your migration to use raw SQL instead of Schema builder.');
            $this->line('See: php artisan rsx:man migrations');
            return false;
        }

        // All validations passed - now remove down() methods
        $processed_migrations = [];
        foreach ($pending_migrations as $migration_path) {
            if (MigrationValidator::remove_down_method($migration_path)) {
                $processed_migrations[] = $migration_path;
            }
        }

        // If we processed any migrations (removed down methods), notify user
        if (!empty($processed_migrations)) {
            $this->info('');
            $this->warn('[WARNING]  Modified migration files:');
            foreach ($processed_migrations as $path) {
                $this->line('  • ' . basename($path) . ' - down() method removed');
            }
            $this->info('');
            $this->line('These migrations have been updated to follow framework standards.');
        }

        return true;
    }

    /**
     * Ensure the migrations table exists in the database
     * Creates it using raw SQL if it doesn't exist
     */
    protected function ensure_migrations_table_exists(): void
    {
        try {
            // Try to query the migrations table
            DB::select('SELECT 1 FROM migrations LIMIT 1');
        } catch (\Exception $e) {
            // Table doesn't exist, create it
            $this->info('Creating migrations table...');

            DB::statement("
                CREATE TABLE IF NOT EXISTS migrations (
                    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
                    migration VARCHAR(255) NOT NULL,
                    batch INT NOT NULL
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
            ");

            $this->info('[OK] Migrations table created');
        }
    }

    /**
     * Run migrations one-by-one with normalization after each
     *
     * Runs pending migrations individually, normalizing schema after each successful
     * migration. This ensures type consistency before subsequent migrations reference
     * newly-created tables.
     *
     * @param \Illuminate\Database\Migrations\Migrator $migrator
     * @param array $migrationPaths
     * @param bool $step
     * @param array $requiredColumnsArgs
     * @return void
     */
    protected function run_migrations_with_normalization($migrator, array $migrationPaths, bool $step, array $requiredColumnsArgs): void
    {
        // Get all migration files
        $files = [];
        foreach ($migrationPaths as $path) {
            if (is_dir($path)) {
                $path_files = glob($path . '/*.php');
                if ($path_files) {
                    foreach ($path_files as $file) {
                        $files[] = $file;
                    }
                }
            }
        }

        // Sort files chronologically by filename
        sort($files);

        // Get already-run migrations
        $repository = $migrator->getRepository();
        $ran = $repository->getRan();

        // Filter to only pending migrations
        $pending = [];
        foreach ($files as $file) {
            $migrationName = $migrator->getMigrationName($file);
            if (!in_array($migrationName, $ran)) {
                $pending[] = $file;
            }
        }

        if (empty($pending)) {
            $this->info('   INFO  Nothing to migrate.');
            return;
        }

        $totalMigrations = count($pending);
        $currentMigration = 1;

        // Run each migration individually with normalization after
        foreach ($pending as $file) {
            $migrationName = $migrator->getMigrationName($file);

            $this->info("\n[$currentMigration/$totalMigrations] Running: $migrationName");
            $this->newLine();

            // Run this single migration
            $migrator->runPending([$file], [
                'pretend' => false,
                'step' => $step
            ]);

            // Run normalization after this migration (if not the last)
            if ($currentMigration < $totalMigrations) {
                $this->info("\n Normalizing schema after migration...\n");

                // Switch to destructive-only query logging
                AppServiceProvider::set_query_log_mode(AppServiceProvider::QUERY_LOG_DESTRUCTIVE_STDOUT);

                $normalizeExitCode = $this->call('migrate:normalize_schema', $requiredColumnsArgs);

                // Restore full query logging
                AppServiceProvider::set_query_log_mode(AppServiceProvider::QUERY_LOG_ALL_STDOUT);

                if ($normalizeExitCode !== 0) {
                    throw new \Exception("Normalization failed after migration: $migrationName");
                }
            }

            $currentMigration++;
        }

        $this->newLine();
        $this->info("[OK] All $totalMigrations migration" . ($totalMigrations > 1 ? 's' : '') . " completed successfully");
    }
}