Add elwig-backend

src/elwig-backend

@@ -0,0 +1,341 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from __future__ import annotations
+from typing import Callable, Optional
+from http.server import BaseHTTPRequestHandler, HTTPServer
+import argparse
+import datetime
+import traceback
+import re
+import base64
+import json
+import sqlite3
+import urllib.parse
+import gzip
+
+
+CNX: sqlite3.Cursor
+USER_FILE: str
+
+
+class BadRequestError(Exception):
+    pass
+
+
+class Filter:
+    def __init__(self, name: str, value: int or str = None):
+        self.name = name
+        self.value = value
+
+    def is_int(self) -> bool:
+        return type(self.value) is int
+
+    def is_str(self) -> bool:
+        return type(self.value) is str
+
+    def is_single(self) -> bool:
+        return self.value is None
+
+    def __repr__(self) -> str:
+        if self.is_single():
+            return self.name
+        elif self.name == 'kgnr':
+            return f'kgnr={self.value:05}'
+        return f'{self.name}={self.value}'
+
+    def __str__(self) -> str:
+        return self.__repr__()
+
+    def __eq__(self, other) -> bool:
+        return self.__repr__() == other.__repr__()
+
+    @staticmethod
+    def from_str(string: str) -> Filter:
+        f = string.split('=', 1)
+        if len(f) == 2:
+            return Filter(f[0], int(f[1]) if f[1].isdigit() else f[1])
+        return Filter(f[0])
+
+
+def sqlite_regexp(pattern: str, value: Optional[str]) -> Optional[bool]:
+    return re.match(pattern, value) is not None if value is not None else None
+
+
+def kmw_to_oe(kmw: float) -> float:
+    return kmw * (4.54 + 0.022 * kmw) if kmw is not None else None
+
+
+def jdmp(value, is_bool: bool = False) -> str:
+    if is_bool and value:
+        return ' true'
+    elif is_bool and not value:
+        return 'false'
+    return json.dumps(value, ensure_ascii=False)
+
+
+def get_delivery_schedule_filter_clauses(filters: list[Filter]) -> list[str]:
+    clauses = []
+    for f in filters:
+        if f.name == 'year' and f.is_int():
+            clauses.append(f"s.year = {f.value}")
+        elif f.name == 'sortid' and f.is_str() and len(f.value) == 2 and f.value.isalpha() and f.value.isupper():
+            clauses.append(f"v.sortid = '{f.value}'")
+        elif f.name == 'date' and f.is_str() and re.match(r'[0-9]{4}-[0-9]{2}-[0-9]{2}', f.value) is not None:
+            clauses.append(f"s.date = '{f.value}'")
+        else:
+            raise BadRequestError(f"Invalid filter '{f}'")
+    return clauses
+
+
+class ElwigApi(BaseHTTPRequestHandler):
+    def send(self, data: str, status_code: int = 200):
+        raw = data.encode('utf-8')
+        self.send_response(status_code)
+        self.send_header('Access-Control-Allow-Origin', '*')
+        self.send_header('Access-Control-Allow-Headers', 'Authorization')
+        self.send_header('Access-Control-Allow-Methods', 'HEAD, GET, OPTIONS')
+        if self.headers.get('Accept-Encoding') and len(data) > 64:
+            accept_encoding = [e.strip() for e in self.headers.get('Accept-Encoding').split(',')]
+            if 'gzip' in accept_encoding:
+                raw = gzip.compress(raw)
+                self.send_header('Content-Encoding', 'gzip')
+        self.send_header('Content-Type', 'application/json; charset=UTF-8')
+        self.send_header('Content-Length', str(len(raw)))
+        self.end_headers()
+        if self.request.type != 'HEAD' and self.request.type != 'OPTIONS':
+            self.wfile.write(raw)
+
+    def error(self, status_code: int, message: str = None):
+        self.send(f'{{"message":{jdmp(message)}}}\n', status_code=status_code)
+
+    def authorize(self) -> (str or None, str or None):
+        try:
+            auth = self.headers.get('Authorization')
+            if auth is None or not auth.startswith('Basic '):
+                self.error(401, 'Unauthorized')
+                return None, None
+            auth = base64.b64decode(auth[6:]).split(b':', 1)
+            if len(auth) != 2:
+                self.error(401, 'Invalid Authorization header')
+                return None, None
+            username, password = auth[0].decode('utf-8'), auth[1].decode('utf-8')
+        except:
+            self.error(401, 'Invalid Authorization header')
+            return None, None
+        with open(USER_FILE, 'r') as file:
+            for line in file:
+                (u, r, p) = line.strip().split(':', 2)
+                if u == username:
+                    if p == password:
+                        return u, r
+                    else:
+                        self.error(401, 'Unauthorized')
+        return None, None
+
+    def exec_collection(self, sql_query: str, fmt: Callable, filters: list[Filter],
+                        offset: int = None, limit: int = None,
+                        distinct: tuple[[str], [int]] = None, sub_fmt: Callable = None):
+        with_clause = re.findall(r'(WITH .*?\))[\s\n]*SELECT', sql_query, flags=re.DOTALL)
+        if len(with_clause) > 0 and '.*' not in with_clause[0]:
+            with_clause = with_clause[0]
+            count_query = sql_query.replace(with_clause, '')
+        else:
+            with_clause = None
+            count_query = sql_query
+        count = f"""SELECT COUNT(DISTINCT {" || '|' || ".join(distinct[0])}) FROM""" if distinct else "SELECT COUNT(*) FROM"
+        count_query = re.sub(r"SELECT [^*]+? FROM", count, count_query, count=1, flags=re.DOTALL)
+        count_query = re.sub(r"(OFFSET|LIMIT) [0-9-]+", '', count_query)
+        count_query = re.sub(r"GROUP BY .*", '', count_query)
+        if with_clause:
+            count_query = with_clause + ' ' + count_query
+        count = CNX.execute(count_query).fetchone()
+        count = count[0] if count is not None else 0
+
+        if limit is not None:
+            if "LIMIT " in sql_query:
+                sql_query = re.sub(r"LIMIT [0-9-]+", f"LIMIT {limit}", sql_query)
+            else:
+                sql_query += f" LIMIT {limit}"
+        if offset is not None:
+            if "OFFSET " in sql_query:
+                sql_query = re.sub(r"OFFSET [0-9-]+", f"OFFSET {offset}", sql_query)
+            else:
+                sql_query += f" OFFSET {offset}"
+        rows = CNX.execute(sql_query)
+
+        data = (f'''{{"filters":[{','.join(f'{{"filter":{jdmp(str(f))}}}' for f in filters)}],'''
+                f'"total":{count},"offset":{offset or 0},"limit":{jdmp(limit)},'
+                f'"data":[')
+        first, first_, cur, last = True, True, None, None
+        for r in rows or []:
+            cur = tuple([r[i] for i in distinct[1]]) if distinct else None
+            if not distinct or cur != last:
+                first_ = True
+                if first:
+                    first = False
+                else:
+                    if distinct and sub_fmt:
+                        data += '\n  ]}'
+                    data += ','
+                data += f'\n  ' + fmt(r)
+            if distinct and sub_fmt:
+                if first_:
+                    data += '['
+                    first_ = False
+                else:
+                    data += ','
+                data += f'\n    ' + sub_fmt(r)
+            last = cur
+        if distinct and sub_fmt and not first:
+            data += '\n  ]}'
+        data += '\n]}\n'
+        self.send(data)
+
+    def do_GET_delivery_schedules(self, filters: list[Filter], offset: int = None, limit: int = None, order: str = None):
+        clauses = get_delivery_schedule_filter_clauses(filters)
+        sql = f"""
+            WITH announcements
+                AS (SELECT year, dsnr, SUM(weight) AS weight
+                    FROM delivery_announcement
+                    GROUP BY year, dsnr)
+            SELECT s.year, s.dsnr, s.date, s.description, s.max_weight, s.cancelled,
+                   COALESCE(a.weight, 0) AS announced_weight,
+                   COALESCE(SUM(p.weight), 0) AS delivered_weight,
+                   STRFTIME('%Y-%m-%dT%H:%M:%SZ', DATETIME(s.ancmt_from, 'unixepoch')),
+                   STRFTIME('%Y-%m-%dT%H:%M:%SZ', DATETIME(s.ancmt_to, 'unixepoch')),
+                   b.zwstid, b.name,
+                   s.attrid, s.cultid
+            FROM delivery_schedule s
+                LEFT JOIN branch b ON b.zwstid = s.zwstid
+                LEFT JOIN announcements a ON (a.year, a.dsnr) = (s.year, s.dsnr)
+                LEFT JOIN delivery_schedule_wine_variety v ON (v.year, v.dsnr) = (s.year, s.dsnr)
+                LEFT JOIN delivery d ON (d.date, d.zwstid) = (s.date, s.zwstid)
+                LEFT JOIN delivery_part p ON (p.year, p.did) = (d.year, d.did) AND p.sortid = v.sortid 
+            """
+        if len(clauses) > 0:
+            sql += f" WHERE {' AND '.join(clauses)}"
+        sql += " GROUP BY s.year, s.dsnr"
+        sql += " ORDER BY s.year, s.date, s.zwstid, s.description, s.dsnr"
+
+        rows1 = CNX.execute("""
+            SELECT date, zwstid, cultid, SUM(weight)
+            FROM delivery d
+                JOIN delivery_part p ON (p.year, p.did) = (d.year, d.did)
+            WHERE (d.date, d.zwstid, COALESCE(p.cultid, '')) IN
+                  (SELECT date, zwstid, COALESCE(cultid, '') FROM delivery_schedule GROUP BY date, zwstid, cultid HAVING COUNT(*) = 1)
+            GROUP BY date, zwstid, cultid
+            """)
+        days1 = {(r[0], r[1], r[2]): r[3] for r in rows1}
+        rows2 = CNX.execute("""
+            SELECT date, zwstid, attrid, SUM(weight)
+            FROM delivery d
+                JOIN delivery_part p ON (p.year, p.did) = (d.year, d.did)
+            WHERE (d.date, d.zwstid, COALESCE(p.attrid, '')) IN
+                  (SELECT date, zwstid, COALESCE(attrid, '') FROM delivery_schedule GROUP BY date, zwstid, attrid HAVING COUNT(*) = 1)
+            GROUP BY date, zwstid, attrid
+            """)
+        days2 = {(r[0], r[1], r[2]): r[3] for r in rows2}
+
+        self.exec_collection(
+            sql,
+            lambda r: f'{{"year":{r[0]:4},"dsnr":{r[1]:2},"date":"{r[2]}",'
+                      f'"branch":{{"zwstid":{jdmp(r[10])},"name":{jdmp(r[11]):20}}},'
+                      f'"description":{jdmp(r[3]):50},'
+                      f'"max_weight":{jdmp(r[4]):6},'
+                      f'"is_cancelled":{jdmp(r[5], is_bool=True)},'
+                      f'"announced_weight":{r[6]:6},'
+                      f'"delivered_weight":{days1.get((r[2], r[10], r[13]), days2.get((r[2], r[10], r[12]), r[7] or 0)):6},'
+                      f'"announcement_from":{jdmp(r[8])},'
+                      f'"announcement_to":{jdmp(r[9])}}}',
+            filters, offset, limit, distinct=(['s.year', 's.dsnr'], [1, 2]))
+
+    def do_HEAD(self):
+        self.do_GET()
+
+    def do_OPTIONS(self):
+        self.send('')
+
+    def do_GET(self):
+        try:
+            username, role = self.authorize()
+            if not username or not role:
+                return
+
+            parts = self.path.split('?', 1)
+            if len(parts) == 1:
+                path, query = parts[0], {}
+            else:
+                path, query = parts[0], {urllib.parse.unquote(s[0]): urllib.parse.unquote(s[-1])
+                                         for s in [p.split('=', 1) for p in parts[1].split('&')]}
+            filters = [Filter.from_str(f) for f in (query['filters'].split(',') if 'filters' in query else [])]
+            offset = int(query['offset']) if 'offset' in query else None
+            limit = int(query['limit']) if 'limit' in query else None
+            order = query['order'] if 'order' in query else None
+
+            if path == '/wine/varieties':
+                self.exec_collection(
+                    "SELECT sortid, type, name, comment FROM wine_variety",
+                    lambda r: f'{{"sortid":"{jdmp(r[0])}","type":"{jdmp(r[1])}","name":"{jdmp(r[2])}","comment":{jdmp(r[3])}}}',
+                    filters)
+            elif path == '/wine/quality_levels':
+                self.exec_collection(
+                    "SELECT qualid, name, min_kmw, predicate FROM wine_quality_level",
+                    lambda r: f'{{"qualid":"{jdmp(r[0])}","name":"{jdmp(r[1])}","min_kmw":{jdmp(r[2])},"is_predicate":{jdmp(r[3], is_bool=True)}}}',
+                    filters)
+            elif path == '/wine/attributes':
+                self.exec_collection(
+                    "SELECT attrid, name FROM wine_attribute",
+                    lambda r: f'{{"attrid":"{jdmp(r[0])}","name":"{jdmp(r[1])}"}}',
+                    filters)
+            elif path == '/wine/cultivations':
+                self.exec_collection(
+                    "SELECT cultid, name, description FROM wine_cultivation",
+                    lambda r: f'{{"cultid":"{jdmp(r[0])}","name":"{jdmp(r[1])}","description":{jdmp(r[2])}}}',
+                    filters)
+            elif path == '/modifiers':
+                self.exec_collection(
+                    "SELECT year, modid, name, ordering FROM modifier",
+                    lambda r: f'{{"year":{jdmp(r[0])},"modid":"{jdmp(r[1])}","name":"{jdmp(r[2])}","ordering":{jdmp(r[3])}}}',
+                    filters)
+            elif path == '/delivery_schedules':
+                self.do_GET_delivery_schedules(filters, offset, limit, order)
+            else:
+                self.error(404, 'Invalid path')
+        except BadRequestError as e:
+            self.error(400, str(e))
+        except Exception as e:
+            traceback.print_exception(e)
+            self.error(500, str(e))
+
+
+def main() -> None:
+    global CNX
+    global USER_FILE
+
+    sqlite3.register_adapter(datetime.date, lambda d: d.strftime('%Y-%m-%d'))
+    sqlite3.register_adapter(datetime.time, lambda t: t.strftime('%H:%M:%S'))
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('db', type=str, metavar='DB')
+    parser.add_argument('userfile', type=str, metavar='USER-FILE')
+    parser.add_argument('-p', '--port', type=int, default=8080)
+    args = parser.parse_args()
+
+    USER_FILE = args.userfile
+    CNX = sqlite3.connect(f'file:{args.db}?mode=ro', uri=True)
+    CNX.create_function('REGEXP', 2, sqlite_regexp, deterministic=True)
+
+    server = HTTPServer(('localhost', args.port), ElwigApi)
+    print(f'Listening on http://localhost:{args.port}')
+    try:
+        server.serve_forever()
+    except KeyboardInterrupt:
+        pass
+    server.server_close()
+    print('Good bye!')
+
+
+if __name__ == '__main__':
+    main()
+