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backend.py

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+import os
+import random
+import sqlite3
+import time
+import zipfile
+
+
+class Backend:
+
+    def __init__(self, db="data.db"):
+        self.db_path = db
+        # 先解压
+        if not os.path.exists(self.db_path) and os.path.exists(self.db_path + ".zip"):
+            with zipfile.ZipFile(self.db_path + ".zip", 'r') as zip_ref:
+                zip_ref.extractall(".")
+
+
+        self.time = time.time()
+        self.title_filter = self.get_source_type()
+        self.global_filter = []
+
+
+
+    def get_question(self):
+        conn = sqlite3.connect(self.db_path)
+        cursor = conn.cursor()
+
+        # 构造 IN 子句的占位符
+        placeholders = ','.join('?' for _ in self.title_filter)
+
+        # 总权重查询
+        total_query = f"""
+            SELECT SUM(count) 
+            FROM questions 
+            WHERE count > 0 AND title IN ({placeholders})
+        """
+
+        #print(total_query)
+        #print(self.title_filter)
+
+        cursor.execute(total_query, self.title_filter)
+        total_weights = cursor.fetchone()[0]
+        if total_weights is None or total_weights == 0:
+            conn.close()
+            return None
+
+        # 生成随机数 [0, total_weights)
+        random_num = random.uniform(0, total_weights)
+
+        # 主查询：加权随机选择
+        query = f"""
+            SELECT *
+            FROM (
+                SELECT *,
+                       SUM(count) OVER (ORDER BY id ROWS UNBOUNDED PRECEDING) AS cum_weight
+                FROM questions
+                WHERE count > 0 AND title IN ({placeholders})
+            )
+            WHERE ? < cum_weight
+            ORDER BY cum_weight
+            LIMIT 1;
+        """
+
+        params = tuple(self.title_filter) + (random_num,)
+        cursor.execute(query, params)
+
+        row = cursor.fetchone()
+        print(total_weights, row)
+
+        conn.close()
+        self.time = time.time()
+
+        return list(row) if row else None
+
+    def update(self, id, state):
+        conn = sqlite3.connect(self.db_path)
+        cursor = conn.cursor()
+
+        # 作对-1 错了+2
+        if state != 0:
+            query = """
+                    UPDATE questions
+                    SET count = count + 2
+                    WHERE id = ?
+                      and count > 0"""
+        else:
+            query = """
+                    UPDATE questions
+                    SET count = count - 1
+                    WHERE id = ?
+                    """
+        cursor.execute(query, (id,))
+
+        # 记录用时
+        query = "INSERT INTO answers_history (id, time_used, state) VALUES (?, ?, ?)"
+        cursor.execute(query, (id, time.time() - self.time, state))
+
+        conn.commit()
+        conn.close()
+
+    def reset_time(self):
+        self.time = time.time()
+
+    def get_acc(self, top_n=0):
+        conn = sqlite3.connect(self.db_path)
+        cursor = conn.cursor()
+
+        try:
+            if top_n > 0:
+                query = """
+                        SELECT CAST(SUM(CASE WHEN state = 0 THEN 1 ELSE 0 END) AS FLOAT) / COUNT(*) AS accuracy
+                        FROM (SELECT state
+                              FROM answers_history
+                              ORDER BY time DESC
+                              LIMIT ?)
+                        """
+                params = (top_n,)
+            else:
+                query = """
+                        SELECT CAST(SUM(CASE WHEN state = 0 THEN 1 ELSE 0 END) AS FLOAT) / COUNT(*) AS accuracy FROM answers_history
+                        """
+                params = ()
+
+            cursor.execute(query, params)
+            result = cursor.fetchone()[0]
+            return result * 100 if result is not None else 0.0
+
+        except sqlite3.Error as e:
+            print(f"数据库错误：{e}")
+            return 0.0
+        finally:
+            conn.close()
+
+    def get_avg_time(self, top_n=0):
+        conn = sqlite3.connect(self.db_path)
+        cursor = conn.cursor()
+
+        try:
+            if top_n > 0:
+                query = """
+                        SELECT CAST(SUM(time_used) AS FLOAT) / COUNT(*) AS accuracy
+                        FROM (SELECT time_used
+                              FROM answers_history
+                              where time_used is not null
+                              ORDER BY time DESC
+                              LIMIT ?)
+                        """
+                params = (top_n,)
+            else:
+                query = """
+                        SELECT CAST(SUM(time_used) AS FLOAT) / COUNT(*) AS accuracy FROM answers_history where time_used is not null
+                        """
+                params = ()
+
+            cursor.execute(query, params)
+            result = cursor.fetchone()[0]
+            return result if result is not None else 0.0
+
+        except sqlite3.Error as e:
+            print(f"数据库错误：{e}")
+            return 0.0
+        finally:
+            conn.close()
+
+    def get_statistics(self):
+        avg_all = self.get_avg_time()
+        avg_50 = self.get_avg_time(50)
+        avg_100 = self.get_avg_time(100)
+
+        result = [
+            ["正确率", f"{self.get_acc():.1f}/60%"],
+            [],
+            ["最近50题正确率", f"{self.get_acc(50):.1f}/60%"],
+            ["最近100题正确率", f"{self.get_acc(120):.1f}/60%"],
+            ["平均耗时", f"{avg_all:.1f}/72s"],
+            ["预计做完用时", f"{avg_all * 1.667:.1f}/120min"],
+            ["50平均耗时", f"{avg_50:.1f}/72s"],
+            ["预计做完用时", f"{avg_50 * 1.667:.1f}/120min"],
+            ["120平均耗时", f"{avg_100:.1f}/72s"],
+            ["预计做完用时", f"{avg_100 * 1.667:.1f}/120min"],
+        ]
+        return result
+
+    def get_source_type(self):
+        conn = sqlite3.connect(self.db_path)
+        cursor = conn.cursor()
+        query = "SELECT DISTINCT title FROM questions"
+        cursor.execute(query)
+        result = cursor.fetchall()
+        new_list = [item[0] for item in result]
+        return new_list
+
+    def set_config(self,a,b):
+        self.title_filter = a
+        self.global_filter = b