#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""pbl_blueprint 派生物生成器（幂等）。

输入：pbl_blueprint/models/{tblname}.json —— 四段式表定义（summary/fields/indexes/codes）
输出：
  1) pbl_blueprint/json/{tblname}.json     —— CRUD 契约定义（根键 = tblname + params(editable/browserfields)）
  2) pbl_blueprint/sql/pbl_blueprint.core.sql —— DDL 派生物（engine=postgresql，禁止手工维护）

用法：python3 scripts/derive_artifacts.py
QC 核对点：json/*.json 与 sql/*.sql 均由本脚本机械派生，改表只需改 models/*.json 后重跑本脚本。
"""
import json
import os
import glob

HERE = os.path.dirname(os.path.abspath(__file__))
PKG = os.path.join(os.path.dirname(HERE), 'pbl_blueprint')
MODELS_DIR = os.path.join(PKG, 'models')
JSON_DIR = os.path.join(PKG, 'json')
SQL_DIR = os.path.join(PKG, 'sql')

# 表 -> dspy 接口前缀（CRUD editable url 用）
API_PREFIX = {
    'pbl_blueprint': 'blueprint',
    'pbl_blueprint_version': 'version',
    'pbl_blueprint_template': 'template',
    'pbl_blueprint_template_item': 'template_item',
}
BROWSER_FIELDS = ('id', 'tenant_id', 'class_id', 'code', 'name', 'blueprint_code',
                  'blueprint_name', 'template_code', 'template_name', 'status',
                  'version_status', 'version_no', 'subobject_type', 'domain_code',
                  'grade_code', 'subject_code', 'complexity_level', 'seq_no',
                  'created_at', 'updated_at')
HEAVY_FIELDS = ('snapshot_json', 'content_json', 'item_payload_json',
                'quality_criteria', 'knowledge_points', 'tags_json')
IMMUTABLE = ('id', 'tenant_id', 'created_by', 'created_at')


def api_prefix(tbl):
    if tbl in API_PREFIX:
        return API_PREFIX[tbl]
    return 'subobject'


def load_models():
    docs = {}
    for p in sorted(glob.glob(os.path.join(MODELS_DIR, '*.json'))):
        tbl = os.path.basename(p)[:-5]
        doc = json.load(open(p, encoding='utf-8'))
        for seg in ('summary', 'fields', 'indexes', 'codes'):
            if seg not in doc:
                raise SystemExit('models/%s.json 缺四段式必需段: %s' % (tbl, seg))
        if not isinstance(doc['fields'], dict):
            raise SystemExit('models/%s.json fields 必须是对象（列名->定义）' % tbl)
        docs[tbl] = doc
    return docs


def build_crud(tbl, doc):
    fields = doc['fields']
    names = list(fields.keys())
    editable = [n for n in names if n not in IMMUTABLE]
    browser = [n for n in names if n in BROWSER_FIELDS]
    alters = {}
    for n, spec in fields.items():
        if spec.get('appcode'):
            alters[n] = {'uitype': 'code', 'appcode': spec['appcode'],
                         'label': spec.get('label', n)}
    a = api_prefix(tbl)
    return {tbl: {
        'summary': doc['summary'].get('label', tbl),
        'alias': tbl + '_crud',
        'params': {
            'sortby': 'created_at',
            'sortorder': 'desc',
            'tenant_scoped': True,
            'browserfields': {
                'fields': browser,
                'alters': alters,
                'exclouded': list(HEAVY_FIELDS),
            },
            'editable': {
                'new_data_url': "{{entire_url('../api/%s_save.dspy')}}" % a,
                'update_data_url': "{{entire_url('../api/%s_save.dspy')}}" % a,
                'delete_data_url': "{{entire_url('../api/%s_delete.dspy')}}" % a,
                'list_data_url': "{{entire_url('../api/%s_list.dspy')}}" % a,
                'get_data_url': "{{entire_url('../api/%s_get.dspy')}}" % a,
                'editexclouded': list(IMMUTABLE),
            },
            'required': [n for n, s in fields.items() if s.get('required')],
            'data_filter': {'AND': [{'field': 'tenant_id', 'op': '=', 'var': 'tenant_id'}]},
        },
        'codes': doc['codes'],
        'table_meta': {
            'pk': 'id',
            'tenant_field': 'tenant_id',
            'soft_delete_field': 'is_deleted',
            'engine': doc['summary'].get('engine', 'postgresql'),
            'indexes': list(doc['indexes'].keys()),
        },
    }}


def col_ddl(name, spec):
    ty = spec['type']
    if ty.startswith('str'):
        return '%s varchar(%s)' % (name, ty[ty.index('(') + 1:ty.index(')')])
    if ty == 'text':
        return '%s text' % name
    if ty == 'int':
        return '%s integer' % name
    if ty.startswith('double'):
        return '%s numeric(18,2)' % name
    if ty == 'datetime':
        return '%s timestamp' % name
    raise SystemExit('未知抽象类型: %s (%s)' % (ty, name))


def build_sql(docs):
    lines = [
        '-- pbl_blueprint 核心表 DDL',
        '-- 本文件由 scripts/derive_artifacts.py 从 pbl_blueprint/models/*.json 机械派生，禁止手工编辑',
        '-- engine: postgresql（与 projects/pbls/env/*.json 的 db.engine 一致）',
        '-- 主键 id 为应用层生成的 str(32)：不使用 SERIAL / BIGSERIAL / nextval / AUTO_INCREMENT',
        '',
    ]
    for tbl in sorted(docs.keys()):
        doc = docs[tbl]
        fields = doc['fields']
        lines.append('-- %s: %s' % (tbl, doc['summary'].get('label', '')))
        cols = ',\n'.join(
            '  ' + col_ddl(k, v) + (' NOT NULL' if (v.get('required') or k == 'id') else '')
            for k, v in fields.items())
        lines.append('CREATE TABLE IF NOT EXISTS %s (' % tbl)
        lines.append(cols)
        lines.append(');')
        for k, v in fields.items():
            lines.append("COMMENT ON COLUMN %s.%s IS '%s';" % (tbl, k, v.get('label', '')))
        lines.append('')
        for iname, isp in doc['indexes'].items():
            if iname == 'primary':
                continue
            uniq = 'UNIQUE ' if isp.get('unique') else ''
            lines.append('CREATE %sINDEX IF NOT EXISTS %s_%s ON %s (%s);' %
                         (uniq, tbl, iname, tbl, ', '.join(isp['fields'])))
        lines.append('')
    return '\n'.join(lines)


def main():
    docs = load_models()
    os.makedirs(JSON_DIR, exist_ok=True)
    os.makedirs(SQL_DIR, exist_ok=True)
    for tbl, doc in docs.items():
        out = os.path.join(JSON_DIR, '%s.json' % tbl)
        with open(out, 'w', encoding='utf-8') as fp:
            json.dump(build_crud(tbl, doc), fp, ensure_ascii=False, indent=2)
    with open(os.path.join(SQL_DIR, 'pbl_blueprint.core.sql'), 'w', encoding='utf-8') as fp:
        fp.write(build_sql(docs))
    print('models=%d json=%d sql_tables=%d' %
          (len(docs), len(glob.glob(os.path.join(JSON_DIR, '*.json'))), len(docs)))


if __name__ == '__main__':
    main()