-- data-ana ClickHouse DDL（5 宽表）.
-- 负责人：ai11（总裁裁决 §2.12 授权 ai11 创建纯 DDL 文件，SRE AI 负责部署脚本）.
-- 对齐文档：services/data-ana/docs/02-architecture-design.md §3.
-- 引擎：ReplacingMergeTree 按 ORDER BY 去重 + version 列保留最新版本（幂等消费保证）.
-- 查询时必须加 FINAL 或使用 argMax 聚合确保去重生效（P0 整改项）.
--
-- 使用方式：
--   clickhouse-client --multiquery < infra/clickhouse/ddl/data_ana.sql

-- 数据库
CREATE DATABASE IF NOT EXISTS edu_analytics;

-- ===== 1. 学生学情宽表 =====
-- 每次成绩写入产生一行，按 ORDER BY 去重保留 last_updated 最大版本.
CREATE TABLE IF NOT EXISTS edu_analytics.student_dashboard_view
(
    student_id         String,
    class_id           String,
    exam_id           String,
    subject_id        String,
    score              Float64,
    rank_in_class      UInt32,
    knowledge_point_id String,
    mastery_level      Float32,           -- 0.0-1.0
    error_count        UInt32,
    last_updated       DateTime64(3, 'UTC')
)
ENGINE = ReplacingMergeTree(last_updated)
PARTITION BY toYYYYMM(last_updated)
ORDER BY (student_id, exam_id, knowledge_point_id)
SETTINGS index_granularity = 8192;

-- ===== 2. 学生错题本 =====
-- 同一 (student_id, question_id) 累计 error_count，按 last_error_time 去重.
CREATE TABLE IF NOT EXISTS edu_analytics.student_errors
(
    student_id          String,
    question_id         String,
    knowledge_point_id  String,
    error_count         UInt32,
    last_error_time     DateTime64(3, 'UTC'),
    content             String DEFAULT ''
)
ENGINE = ReplacingMergeTree(last_error_time)
PARTITION BY toYYYYMM(last_error_time)
ORDER BY (student_id, question_id);

-- ===== 3. 知识点掌握度历史快照 =====
-- 每次掌握度计算产生新版本，支持趋势查询.
CREATE TABLE IF NOT EXISTS edu_analytics.mastery_snapshot
(
    student_id          String,
    knowledge_point_id  String,
    subject_id          String,
    mastery_level       Float32,                                    -- 0.0-1.0
    calculated_at       DateTime64(3, 'UTC'),
    calculation_method  LowCardinality(String)              -- 'weighted_moving_avg' / 'simple_avg' / 'forgetting_curve'
)
ENGINE = MergeTree
PARTITION BY toYYYYMM(calculated_at)
ORDER BY (student_id, knowledge_point_id, calculated_at);

-- ===== 4. 学生考勤记录 =====
-- core-edu attendance 表 CDC 同步，同一记录多版本去重.
CREATE TABLE IF NOT EXISTS edu_analytics.attendance_logs
(
    student_id          String,
    class_id            String,
    attendance_date     Date,
    status              LowCardinality(String),              -- 'present' / 'absent' / 'late' / 'leave'
    recorded_by         String,                              -- 教师用户 ID
    remark              String DEFAULT '',
    occurred_at         DateTime64(3, 'UTC')
)
ENGINE = ReplacingMergeTree(occurred_at)
PARTITION BY toYYYYMM(attendance_date)
ORDER BY (student_id, class_id, attendance_date);

-- ===== 5. AI 用量计费记录 =====
-- ai 服务通过 Kafka 事件投递，data-ana 消费落库，按 request_id 幂等去重.
CREATE TABLE IF NOT EXISTS edu_analytics.ai_usage_log
(
    request_id          String,
    user_id             String,
    provider            LowCardinality(String),              -- 'openai' / 'anthropic' / 'baichuan' / 'local'
    model               LowCardinality(String),
    prompt_tokens       UInt32,
    completion_tokens   UInt32,
    total_tokens        UInt32,
    latency_ms          UInt32,
    success             Boolean,
    cost_cents          UInt32,                              -- 计费（分），便于聚合
    occurred_at         DateTime64(3, 'UTC')
)
ENGINE = ReplacingMergeTree(occurred_at)
PARTITION BY toYYYYMM(occurred_at)
ORDER BY (request_id);