#!/usr/bin/env python3
"""Generate DDL from SageAPI model JSON definitions."""
import json
import os

def generate_ddl(models_dir='models', output_path='db/schema.sql'):
    os.makedirs(os.path.dirname(output_path), exist_ok=True)
    ddl_lines = ['-- SageAPI DDL (auto-generated)', '']

    for f in sorted(os.listdir(models_dir)):
        if not f.endswith('.json'):
            continue
        with open(os.path.join(models_dir, f)) as fh:
            data = json.load(fh)

        summary = data['summary'][0]
        tblname = summary['name']
        primary = summary['primary']
        btick = '`'

        ddl_lines.append(f'CREATE TABLE IF NOT EXISTS {btick}{tblname}{btick} (')

        col_defs = []
        for field in data['fields']:
            nullable = 'NULL' if field.get('nullable', True) else 'NOT NULL'
            default = ''
            if field.get('default') is not None:
                d = field['default']
                if d == 'CURRENT_TIMESTAMP':
                    default = "DEFAULT CURRENT_TIMESTAMP"
                elif d == '':
                    default = "DEFAULT ''"
                elif isinstance(d, str):
                    default = f"DEFAULT '{d}'"
                else:
                    default = f"DEFAULT {d}"
            comment = f"COMMENT '{field.get('comment', '')}'"
            fname = f'{btick}{field["name"]}{btick}'
            col_defs.append(f'  {fname} {field["type"]} {nullable} {default} {comment}'.strip())

        pk = f'{btick}{primary}{btick}'
        col_defs.append(f'  PRIMARY KEY ({pk})')
        ddl_lines.append(',\n'.join(col_defs))
        ddl_lines.append(') ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;')
        ddl_lines.append('')

        tbl = f'{btick}{tblname}{btick}'
        for idx in data.get('idxfields', []):
            unique = 'UNIQUE' if idx.get('unique') else 'INDEX'
            cols = ','.join(f'{btick}{c}{btick}' for c in idx['fields'])
            idx_name = f'{btick}{idx["name"]}{btick}'
            ddl_lines.append(f'ALTER TABLE {tbl} ADD {unique} {idx_name} ({cols});')
            ddl_lines.append('')

    with open(output_path, 'w') as fh:
        fh.write('\n'.join(ddl_lines))
    print(f'  Generated: {output_path} ({len(ddl_lines)} lines)')

if __name__ == '__main__':
    generate_ddl()