charging-cabinet/software/api-server/src/routes/energy_stats.rs

//! 能耗管理 API — 总览、排行、趋势、导出
//!
//! **数据源：`charge_records` 实时聚合**（不再读写 `energy_stats` 表）。
//!
//! `energy_stats` 是"按天快照"的汇总表，但全仓**没有任何写入方**（无 INSERT/REPLACE），
//! 生产与测试库该表恒为 0 行 → 原先的 summary / 柜排名 / 项目统计 / 趋势 / 导出**全部恒为 0**
//! （客户侧表现为"没用电"）。真实数据源是 `charge_records`：每次充电结束由订单结算
//! 写入一条（含 `cabinet_id` / `compartment_id` / `start_time` / `end_time` / `energy` / `max_temperature` / `status`）。
//! 因此这里统一改为**按时间范围 + 组织隔离直接聚合 `charge_records`**。
//!
//! 口径说明（详见 [`time_window`] 与 `charge_records` 的 DDL 注释）：
//! - 时间字段统一用 `start_time`（不是 `end_time`）：与 `h5.rs` 的今日统计
//!   （`DATE(cr.start_time) = CURDATE()`）以及"充电记录"列表的时间筛选口径一致，
//!   且每笔充电记录**只归属它开始的那一天**，不会因跨天而当天重复计数；
//! - `energy` 单位为 **Wh**（`workers/report_worker.rs` 结算时写入 `energy::mwh_to_wh(mwh)`）；
//! - 电费估算按 ¥0.80/kWh 计算：`Wh × 80(分/kWh) / 1000 / 100` = 元。
//!
//! `energy_stats` 表**保留不删**（历史语义/回滚余地），但本模块已完全不再引用它。

use axum::extract::{Query, State};
use axum::Json;
use serde::Deserialize;
use serde_json::{json, Value};

use crate::error::AppError;
use crate::middleware::auth::{self, CurrentUser};

/// 电费单价，0.80 元/kWh = 80 分 / 1000 Wh
const COST_PER_WH_CENT: i64 = 80;

/// 趋势查询 `range`（天数）的合法区间上限，防超大值拖垮查询
const TREND_RANGE_MAX: i64 = 3650;
/// 趋势查询 `range` 的合法区间下限（至少 1 天）
const TREND_RANGE_MIN: i64 = 1;
/// 导出明细单次最大行数（防止无上限导出把内存/Excel 撑爆）
const EXPORT_MAX_ROWS: i64 = 100_000;

/// 聚合表达式：`energy` 列在 pms 是 BIGINT、在 pms_dev 是 DECIMAL，
/// 统一 `CAST(... AS SIGNED)` 后交给 Rust `i64`；`COALESCE` 保证无数据时为 0 而非 NULL。
const SUM_ENERGY_SIGNED: &str = "CAST(COALESCE(SUM(cr.energy), 0) AS SIGNED)";
/// 聚合表达式：充电次数。`COUNT(*)` 原生类型是 BIGINT UNSIGNED，
/// 不能直接解码成 `i64`（sqlx 类型不匹配），必须 CAST。
const COUNT_CHARGES_SIGNED: &str = "CAST(COUNT(*) AS SIGNED)";

/// 能耗聚合的时间窗口 SQL 片段（全部按 `cr.start_time` 半开区间 `[起, 止)`）。
///
/// # 为什么用半开区间而不是 `DATE(cr.start_time) = CURDATE()`
/// `DATE(列) = 常量` 会让 `start_time` 上的索引失效（列被函数包裹 ⇒ 无法走 range scan），
/// 而 `cr.start_time >= 起 AND cr.start_time < 止` 是**等价的**且能命中
/// `idx_charge_records_start_time`。时刻口径与 `DATE(...)` 完全一致：
/// 只按"充电开始的那一刻"归属，不用 `end_time`。
mod time_window {
    /// 今日：`[今天 00:00:00, 明天 00:00:00)`
    pub const TODAY: &str =
        "cr.start_time >= CURDATE() AND cr.start_time < CURDATE() + INTERVAL 1 DAY";

    /// 本月：`[本月 1 日 00:00:00, 下月 1 日 00:00:00)`
    ///
    /// 原 `energy_stats` 实现只有下界（`stat_date >= 本月1日`），因为 `stat_date` 是"按天快照"、
    /// 不存在未来日期。换成时间戳列后补上上界：口径不变（仍只含本月），
    /// 同时避免时钟偏移产生的未来行被算进本月。
    pub const THIS_MONTH: &str = "cr.start_time >= DATE_FORMAT(CURDATE(), '%Y-%m-01') \
                                  AND cr.start_time < DATE_FORMAT(CURDATE() + INTERVAL 1 MONTH, '%Y-%m-01')";

    /// 导出用的"结束日期"（含当天）：`end_date <= ?` 在 DATE 列上原本含当天，
    /// 换成时间戳列后必须写成 `< 次日 00:00:00` 才是同样的"含当天"语义。
    pub const BEFORE_NEXT_DAY: &str = "cr.start_time < DATE_ADD(?, INTERVAL 1 DAY)";
}

/// 把外部传入的 `range` 夹到合法区间，防负数 / 0 / 超大值
/// （负数会让 `DATE_SUB(..., INTERVAL -5 DAY)` 变成"未来 5 天"，超大值会扫全表）。
fn clamp_range(range: i64) -> i64 {
    range.clamp(TREND_RANGE_MIN, TREND_RANGE_MAX)
}

/// 趋势查询参数
#[derive(Debug, Deserialize)]
pub struct TrendQuery {
    /// day | week | month
    #[serde(default = "default_granularity")]
    pub granularity: String,
    /// 天数范围，默认30天
    #[serde(default = "default_range")]
    pub range: i64,
}

/// 导出查询参数
#[derive(Debug, Deserialize)]
pub struct ExportQuery {
    pub cabinet_id: Option<i64>,
    pub project_id: Option<i64>,
    pub start_date: Option<String>,
    pub end_date: Option<String>,
}

/// 柜子排行行
#[derive(Debug, sqlx::FromRow)]
struct CabinetRankRow {
    id: i64,
    abstract_id: String,
    name: Option<String>,
    today_energy: Option<i64>,
    month_energy: Option<i64>,
}

/// 项目统计行
#[derive(Debug, sqlx::FromRow)]
struct ProjectStatRow {
    id: i64,
    name: String,
    cabinet_count: i64,
    today_energy: Option<i64>,
    month_energy: Option<i64>,
}

/// 趋势数据行
#[derive(Debug, sqlx::FromRow)]
struct TrendRow {
    period: String,  // 日期或周/月标识
    energy: Option<i64>,
    charge_count: Option<i64>,
}

/// 能耗明细行（用于导出）
#[derive(Debug, sqlx::FromRow)]
struct EnergyDetailRow {
    stat_date: chrono::NaiveDate,
    cabinet_id: i64,
    cabinet_name: Option<String>,
    project_name: Option<String>,
    total_energy: Option<i64>,
    charge_count: Option<i64>,
}

fn default_granularity() -> String { "day".to_string() }
fn default_range() -> i64 { 30 }

// ---------------------------------------------------------------------------
// 过滤条件构造（组织隔离 + 数据范围，两处口径必须完全一致）
// ---------------------------------------------------------------------------

/// `charge_records cr` 上的过滤片段：组织隔离 **∧** 数据范围（项目级）
///
/// - 未配置数据范围 ⇒ 只有组织条件（与今天完全一致）；
/// - 无组织的客户侧账号 ⇒ ` AND 1=0`（空集，绝不退化成"全部"）；
/// - 总管理员 ⇒ 两个条件都为空（豁免）。
///
/// 返回的是**条件后缀**（调用方拼在 `WHERE {时间窗口}` 之后）⇒ 这里直接 `push_str`
/// 追加 ` AND ...`；**不能**用 `append_where`（空串时会补 `WHERE`，拼出 `WHERE a WHERE b`）。
fn charge_record_filters(user: &CurrentUser) -> (String, Vec<String>) {
    let (mut cond, mut binds): (String, Vec<String>) = if user.role_level >= 2 {
        (String::new(), vec![])
    } else if let Some(oid) = user.organization_id {
        (
            " AND cr.cabinet_id IN (SELECT c.id FROM cabinets c JOIN projects p ON c.project_id = p.id WHERE p.organization_id = ?)".to_string(),
            vec![oid.to_string()],
        )
    } else {
        (" AND 1=0".to_string(), vec![])
    };

    let (scope_cond, scope_binds) = user.effective_scope().cabinet_condition("cr.cabinet_id");
    cond.push_str(&scope_cond);
    binds.extend(scope_binds);

    (cond, binds)
}

/// 统计当前用户可见的柜子数量（`online_only = true` 时只算在线柜子）
///
/// 口径与设备列表一致：非总管理员经 `cabinets → projects` 组织过滤，
/// 再叠加数据范围的项目收窄。
async fn count_visible_cabinets(
    pool: &sqlx::MySqlPool,
    user: &CurrentUser,
    online_only: bool,
) -> Result<i64, AppError> {
    if user.role_level >= 2 {
        let sql = if online_only {
            "SELECT COUNT(*) FROM cabinets WHERE status = 1"
        } else {
            "SELECT COUNT(*) FROM cabinets"
        };
        return Ok(sqlx::query_scalar(sql).fetch_one(pool).await?);
    }

    let Some(oid) = user.organization_id else {
        return Ok(0);
    };

    let (scope_cond, scope_binds) = user.effective_scope().project_condition("c.project_id");
    let status_cond = if online_only { " AND c.status = 1" } else { "" };
    let sql = format!(
        "SELECT COUNT(*) FROM cabinets c JOIN projects p ON c.project_id = p.id WHERE p.organization_id = ?{}{}",
        status_cond, scope_cond
    );
    let mut query = sqlx::query_scalar::<_, i64>(&sql).bind(oid);
    for bind in &scope_binds {
        query = query.bind(bind);
    }
    Ok(query.fetch_one(pool).await?)
}

/// GET /api/energy-stats/summary — 总览
///
/// 返回今日/本月能耗、电费估算、柜子/在线数量。
pub async fn get_summary(
    user: CurrentUser,
    State(state): State<super::AppState>,
) -> Result<Json<Value>, AppError> {
    auth::check_permission(&user, "energy:view")?;
    let pool = &state.mysql;

    // 今天/本月能耗的过滤条件 = 组织隔离 + 数据范围（项目级，未配置 = 不限制）
    let (org_filter, org_binds) = charge_record_filters(&user);

    // 今日总能耗：聚合 charge_records（原来是 energy_stats.stat_date = CURDATE()）
    let today_sql = format!(
        "SELECT {} FROM charge_records cr WHERE {}{}",
        SUM_ENERGY_SIGNED,
        time_window::TODAY,
        org_filter
    );
    let mut today_q = sqlx::query_scalar::<_, i64>(&today_sql);
    for v in &org_binds { today_q = today_q.bind(v); }
    let today_energy: i64 = today_q.fetch_one(pool).await?;

    // 本月总能耗：聚合 charge_records（原来是 energy_stats.stat_date >= 本月1日）
    let month_sql = format!(
        "SELECT {} FROM charge_records cr WHERE {}{}",
        SUM_ENERGY_SIGNED,
        time_window::THIS_MONTH,
        org_filter
    );
    let mut month_q = sqlx::query_scalar::<_, i64>(&month_sql);
    for v in &org_binds { month_q = month_q.bind(v); }
    let month_energy: i64 = month_q.fetch_one(pool).await?;

    // 柜子总数 / 在线柜子数（含组织过滤 + 数据范围）
    let cabinet_count = count_visible_cabinets(pool, &user, false).await?;
    let online_count = count_visible_cabinets(pool, &user, true).await?;

    Ok(Json(json!({
        "code": 0,
        "data": {
            "today_energy": today_energy,
            "month_energy": month_energy,
            "estimated_cost": (month_energy * COST_PER_WH_CENT / 1000) as f64 / 100.0,
            "cabinet_count": cabinet_count,
            "online_count": online_count,
        },
        "message": "ok"
    })))
}

/// GET /api/energy-stats/cabinets — 柜子能耗排行
///
/// 按今日能耗降序排列，返回柜子列表及今日/本月能耗。
pub async fn get_cabinet_ranking(
    user: CurrentUser,
    State(state): State<super::AppState>,
) -> Result<Json<Value>, AppError> {
    auth::check_permission(&user, "energy:view")?;
    let pool = &state.mysql;

    // 组织过滤：INNER JOIN projects 把可见范围限制在用户所属组织
    // （口径与原实现完全一致，只是不再经过 energy_stats）
    let (org_join, org_binds): (String, Vec<String>) = if user.role_level >= 2 {
        (String::new(), vec![])
    } else if let Some(oid) = user.organization_id {
        (
            " JOIN projects p ON c.project_id = p.id AND p.organization_id = ?".to_string(),
            vec![oid.to_string()],
        )
    } else {
        (" JOIN projects p ON 1=0".to_string(), vec![])
    };

    // 数据范围（项目级）叠加：未配置 = 不限制；总管理员豁免。
    // 这里是 **JOIN 片段后缀**（拼在 `FROM cabinets c {}` 位置），直接原样拼接 ` AND ...`。
    let (scope_cond, scope_binds) = user.effective_scope().project_condition("c.project_id");
    let (org_join, org_binds) = {
        let mut join = org_join;
        let mut binds = org_binds;
        join.push_str(&scope_cond);
        binds.extend(scope_binds);
        (join, binds)
    };

    // 今日/本月能耗改为「按 cabinet_id 聚合 charge_records」的两个派生表：
    // 每个柜子至多一行，LEFT JOIN 到 cabinets 后语义与原 energy_stats 版本一致。
    //
    // `COALESCE(c.abstract_id, '')`：`abstract_id` 已被迁移改成**可空**（老数据/联调库里就有 NULL），
    // 而 `CabinetRankRow.abstract_id` 是 `String` ⇒ 遇到 NULL 会让整条查询解码失败、接口 500。
    // 响应字段名与类型不变（仍是字符串），只是把 NULL 显示为空串而不是让整个排行崩掉。
    let sql = format!(
        "SELECT c.id, COALESCE(c.abstract_id, '') AS abstract_id, c.name, \
         CAST(COALESCE(cr_today.today_total, 0) AS SIGNED) AS today_energy, \
         CAST(COALESCE(cr_month.month_total, 0) AS SIGNED) AS month_energy \
         FROM cabinets c \
         LEFT JOIN ( \
             SELECT cr.cabinet_id, SUM(cr.energy) AS today_total \
             FROM charge_records cr \
             WHERE {today} \
             GROUP BY cr.cabinet_id \
         ) cr_today ON c.id = cr_today.cabinet_id \
         LEFT JOIN ( \
             SELECT cr.cabinet_id, SUM(cr.energy) AS month_total \
             FROM charge_records cr \
             WHERE {month} \
             GROUP BY cr.cabinet_id \
         ) cr_month ON c.id = cr_month.cabinet_id \
         {} \
         ORDER BY today_energy DESC, c.id ASC",
        org_join,
        today = time_window::TODAY,
        month = time_window::THIS_MONTH,
    );
    let mut query = sqlx::query_as::<_, CabinetRankRow>(&sql);
    for v in &org_binds { query = query.bind(v); }
    let rows = query.fetch_all(pool).await?;

    let list: Vec<Value> = rows.iter().map(|r| {
        json!({
            "cabinet_id": r.id,
            "abstract_id": r.abstract_id,
            "name": r.name,
            "today_energy": r.today_energy.unwrap_or(0),
            "month_energy": r.month_energy.unwrap_or(0),
        })
    }).collect();

    Ok(Json(json!({
        "code": 0,
        "data": list,
        "message": "ok"
    })))
}

/// GET /api/energy-stats/projects — 项目能耗统计
///
/// 按今日能耗降序排列，返回项目级聚合数据。
pub async fn get_project_stats(
    user: CurrentUser,
    State(state): State<super::AppState>,
) -> Result<Json<Value>, AppError> {
    auth::check_permission(&user, "energy:view")?;
    let pool = &state.mysql;

    let (org_filter, org_binds): (String, Vec<String>) = if user.role_level >= 2 {
        (String::new(), vec![])
    } else if let Some(oid) = user.organization_id {
        (" WHERE p.organization_id = ?".to_string(), vec![oid.to_string()])
    } else {
        (" WHERE 1=0".to_string(), vec![])
    };

    // 数据范围（项目级）叠加：只统计范围内项目的能耗（未配置 = 不限制）。
    // 这里是 **WHERE 后缀**（拼在 `GROUP BY` 之前），直接原样拼接 ` AND ...`。
    let (scope_cond, scope_binds) = user.effective_scope().project_condition("p.id");
    let (org_filter, org_binds) = {
        let mut cond = org_filter;
        let mut binds = org_binds;
        cond.push_str(&scope_cond);
        binds.extend(scope_binds);
        (cond, binds)
    };

    // `charge_records` 只有 `cabinet_id`，项目维度必须经 cabinets → projects 关联；
    // 两个派生表都**按 cabinet_id 聚合**（每柜一行），避免"记录级 JOIN 让 SUM 被放大 N 倍"：
    // 若直接 LEFT JOIN charge_records 再 GROUP BY 项目，则本月汇总会被今天的记录条数重复累加。
    let sql = format!(
        "SELECT p.id, p.name, \
         COUNT(DISTINCT c.id) AS cabinet_count, \
         CAST(COALESCE(SUM(cr_today.today_total), 0) AS SIGNED) AS today_energy, \
         CAST(COALESCE(SUM(cr_month.month_total), 0) AS SIGNED) AS month_energy \
         FROM projects p \
         LEFT JOIN cabinets c ON p.id = c.project_id \
         LEFT JOIN ( \
             SELECT cr.cabinet_id, SUM(cr.energy) AS today_total \
             FROM charge_records cr \
             WHERE {today} \
             GROUP BY cr.cabinet_id \
         ) cr_today ON c.id = cr_today.cabinet_id \
         LEFT JOIN ( \
             SELECT cr.cabinet_id, SUM(cr.energy) AS month_total \
             FROM charge_records cr \
             WHERE {month} \
             GROUP BY cr.cabinet_id \
         ) cr_month ON c.id = cr_month.cabinet_id \
         {} \
         GROUP BY p.id, p.name \
         ORDER BY today_energy DESC, p.id ASC",
        org_filter,
        today = time_window::TODAY,
        month = time_window::THIS_MONTH,
    );
    let mut query = sqlx::query_as::<_, ProjectStatRow>(&sql);
    for v in &org_binds { query = query.bind(v); }
    let rows = query.fetch_all(pool).await?;

    let list: Vec<Value> = rows.iter().map(|r| {
        json!({
            "project_id": r.id,
            "name": r.name,
            "cabinet_count": r.cabinet_count,
            "today_energy": r.today_energy.unwrap_or(0),
            "month_energy": r.month_energy.unwrap_or(0),
        })
    }).collect();

    Ok(Json(json!({
        "code": 0,
        "data": list,
        "message": "ok"
    })))
}

/// GET /api/energy-stats/trend — 趋势数据
///
/// granularity: day | week | month, 默认 day
/// range: 天数范围, 默认 30
pub async fn get_trend(
    user: CurrentUser,
    State(state): State<super::AppState>,
    Query(params): Query<TrendQuery>,
) -> Result<Json<Value>, AppError> {
    auth::check_permission(&user, "energy:view")?;
    let pool = &state.mysql;

    // 组织过滤：cr.cabinet_id → cabinets.project_id → projects.organization_id
    // （口径与原实现完全一致，仅把别名 es → cr）+ 数据范围（项目级）
    let (org_filter, org_binds) = charge_record_filters(&user);

    // range 必须夹紧：负数会让 DATE_SUB 变成"未来 N 天"，超大值会拖垮查询
    let range = clamp_range(params.range);

    // 前端的粒度取值只有 day / week / month（见 software/web/src/pages/energy/index.tsx 的
    // Select options），未知取值按 day 处理（与原实现一致，不报错）。
    //
    // 三档都改为「按 period 分组聚合 charge_records」：
    // 原 day 分支没有 GROUP BY（直接吐 energy_stats 的行），而换到 charge_records 后
    // 一天会有多条记录，**必须按 DATE(start_time) 分组**，否则同一 period 会重复出现多行，
    // 折线图/柱状图的 X 轴会重复。period 文本格式与原实现保持一致
    // （day = 'YYYY-MM-DD'，week = '%Y-%u'，month = '%Y-%m'），前端只把它当分类标签用。
    let (period_expr, group_expr) = match params.granularity.as_str() {
        "week" => ("DATE_FORMAT(cr.start_time, '%Y-%u')", "period"),
        "month" => ("DATE_FORMAT(cr.start_time, '%Y-%m')", "period"),
        _ => ("DATE_FORMAT(cr.start_time, '%Y-%m-%d')", "period"),
    };

    let sql = format!(
        "SELECT {} AS period, {} AS energy, {} AS charge_count \
         FROM charge_records cr \
         WHERE cr.start_time >= DATE_SUB(CURDATE(), INTERVAL ? DAY){} \
         GROUP BY {} ORDER BY period ASC",
        period_expr,
        SUM_ENERGY_SIGNED,
        COUNT_CHARGES_SIGNED,
        org_filter,
        group_expr
    );
    let mut q = sqlx::query_as::<_, TrendRow>(&sql).bind(range);
    for v in &org_binds { q = q.bind(v); }
    let rows = q.fetch_all(pool).await?;

    let list: Vec<Value> = rows.iter().map(|r| {
        json!({
            "period": r.period,
            "energy": r.energy.unwrap_or(0),
            "charge_count": r.charge_count.unwrap_or(0),
        })
    }).collect();

    Ok(Json(json!({
        "code": 0,
        "data": {
            "granularity": params.granularity,
            "list": list,
        },
        "message": "ok"
    })))
}

/// GET /api/energy-stats/export — 异步导出能耗报表
pub async fn export_energy_stats(
    user: CurrentUser,
    State(state): State<super::AppState>,
    Query(params): Query<ExportQuery>,
) -> Result<Json<Value>, AppError> {
    auth::check_permission(&user, "energy:export")?;
    let user_id = user.user_id;
    let file_name = generate_export_filename(&params);

    // 序列化查询参数（含组织过滤信息 + 数据范围）
    let query_json = serde_json::to_string(&json!({
        "cabinet_id": params.cabinet_id,
        "project_id": params.project_id,
        "start_date": params.start_date,
        "end_date": params.end_date,
        "org_id": user.organization_id,
        "role_level": user.role_level,
        // 数据范围（项目级白名单）必须随任务一起落库：导出在后台跑，
        // 不带过去就会绕过 scope（越权导出更大范围）
        "scope_project_ids": user.effective_scope().project_ids,
    }))
    .unwrap_or_default();

    // 插入下载任务
    let result = sqlx::query(
        "INSERT INTO download_tasks (user_id, task_type, status, file_name, error_message) \
         VALUES (?, ?, 0, ?, ?)"
    )
    .bind(user_id)
    .bind("energy_stats")
    .bind(&file_name)
    .bind(&query_json)
    .execute(&state.mysql)
    .await?;

    let task_id = result.last_insert_id() as i64;

    // 后台异步生成 Excel
    let pool = state.mysql.clone();
    tokio::spawn(async move {
        if let Err(e) = generate_energy_excel(pool, task_id).await {
            tracing::error!("导出能耗统计失败 task_id={}: {}", task_id, e);
        }
    });

    Ok(Json(json!({
        "code": 0,
        "data": { "task_id": task_id },
        "message": "导出任务已创建"
    })))
}

/// 生成导出文件名
fn generate_export_filename(params: &ExportQuery) -> String {
    let start = params
        .start_date
        .as_ref()
        .map(|s| s.replace('-', ""))
        .unwrap_or_default();
    let end = params
        .end_date
        .as_ref()
        .map(|s| s.replace('-', ""))
        .unwrap_or_default();
    format!("能耗统计_{}-{}.xlsx", start, end)
}

/// 构建导出条件
///
/// 列名口径：`cabinet_id` 由 `es.` 改为 `cr.`；日期由 `stat_date`（DATE 列）改为
/// `start_time`（TIMESTAMP 列），并保持「含当天」的语义（见 `time_window::BEFORE_NEXT_DAY`）。
fn build_export_clause(
    cabinet_id: Option<i64>,
    project_id: Option<i64>,
    start_date: Option<&str>,
    end_date: Option<&str>,
) -> (String, Vec<String>) {
    let mut conditions = Vec::new();
    let mut bind_values = Vec::new();

    if let Some(id) = cabinet_id {
        conditions.push("cr.cabinet_id = ?");
        bind_values.push(id.to_string());
    }
    if let Some(id) = project_id {
        conditions.push("c.project_id = ?");
        bind_values.push(id.to_string());
    }
    if let Some(d) = start_date {
        conditions.push("cr.start_time >= ?");
        bind_values.push(d.to_string());
    }
    if let Some(d) = end_date {
        conditions.push(time_window::BEFORE_NEXT_DAY);
        bind_values.push(d.to_string());
    }

    let clause = if conditions.is_empty() {
        String::new()
    } else {
        format!("WHERE {}", conditions.join(" AND "))
    };
    (clause, bind_values)
}

/// 读取导出任务的文件名与查询参数
///
/// 任务参数以 JSON 形式临时存放在 download_tasks.error_message 中。
async fn load_export_task(
    pool: &sqlx::MySqlPool,
    task_id: i64,
) -> Result<(String, Value), Box<dyn std::error::Error + Send + Sync>> {
    let row: Option<(String, String)> = sqlx::query_as(
        "SELECT file_name, error_message FROM download_tasks WHERE id = ?"
    )
    .bind(task_id)
    .fetch_optional(pool)
    .await?;

    let (file_name, query_json) = row.ok_or("任务不存在")?;
    let params: Value = serde_json::from_str(&query_json).unwrap_or(json!({}));
    Ok((file_name, params))
}

/// 按导出参数构建 WHERE 子句与绑定值（含组织过滤）
fn build_export_where(params: &Value) -> (String, Vec<String>) {
    let (mut where_clause, mut bind_values) = build_export_clause(
        params.get("cabinet_id").and_then(|v| v.as_i64()),
        params.get("project_id").and_then(|v| v.as_i64()),
        params.get("start_date").and_then(|v| v.as_str()),
        params.get("end_date").and_then(|v| v.as_str()),
    );

    // 组织过滤（非总管理员）
    let role_level = params.get("role_level").and_then(|v| v.as_i64()).unwrap_or(0);
    let org_id = params.get("org_id").and_then(|v| v.as_i64());
    if role_level < 2 {
        if let Some(oid) = org_id {
            let prefix = if where_clause.is_empty() { "WHERE " } else { " AND " };
            where_clause.push_str(&format!("{}cr.cabinet_id IN (SELECT c.id FROM cabinets c JOIN projects p ON c.project_id = p.id WHERE p.organization_id = ?)", prefix));
            bind_values.push(oid.to_string());
        } else {
            let prefix = if where_clause.is_empty() { "WHERE " } else { " AND " };
            where_clause.push_str(&format!("{}1=0", prefix));
        }
    }

    // 数据范围（非总管理员）：与在线查询同一套项目级收窄
    if role_level < 2 {
        let project_ids: Vec<i64> = params
            .get("scope_project_ids")
            .and_then(|v| v.as_array())
            .map(|arr| arr.iter().filter_map(|v| v.as_i64()).collect())
            .unwrap_or_default();
        let (scope_cond, scope_binds) =
            auth::UserScope { project_ids }.cabinet_condition("cr.cabinet_id");
        auth::append_where(&mut where_clause, &scope_cond);
        bind_values.extend(scope_binds);
    }

    (where_clause, bind_values)
}

/// 查询能耗明细行（按「日期 + 柜子」聚合 `charge_records`）
///
/// 原来直接读 `energy_stats`（每柜每天一行）；改为聚合后**必须显式分组**，
/// 分组键 = `DATE(start_time)` + `cabinet_id` + 柜名/项目名（`ONLY_FULL_GROUP_BY` 下
/// 非聚合列必须出现在 GROUP BY 中），输出列与原结构体完全一致。
async fn fetch_energy_detail_rows(
    pool: &sqlx::MySqlPool,
    where_clause: &str,
    bind_values: &[String],
) -> Result<Vec<EnergyDetailRow>, sqlx::Error> {
    // 组织隔离/筛选条件加在 WHERE 里，可能整段为空 ⇒ 这里必须自己兜住
    // `start_time IS NULL`（该列可空）：`DATE(NULL)` 会是 NULL，
    // 反序列化成 `chrono::NaiveDate` 会直接失败，让整个导出任务挂掉。
    let where_clause = if where_clause.is_empty() {
        "WHERE cr.start_time IS NOT NULL".to_string()
    } else {
        format!("{} AND cr.start_time IS NOT NULL", where_clause)
    };

    let sql = format!(
         "SELECT DATE(cr.start_time) AS stat_date, cr.cabinet_id, c.name AS cabinet_name, \
          p.name AS project_name, \
          CAST(COALESCE(SUM(cr.energy), 0) AS SIGNED) AS total_energy, \
          CAST(COUNT(*) AS SIGNED) AS charge_count \
         FROM charge_records cr \
         LEFT JOIN cabinets c ON cr.cabinet_id = c.id \
         LEFT JOIN projects p ON c.project_id = p.id \
         {} \
         GROUP BY DATE(cr.start_time), cr.cabinet_id, c.name, p.name \
         ORDER BY stat_date DESC, cr.cabinet_id ASC \
         LIMIT {}",
        where_clause, EXPORT_MAX_ROWS
    );

    let mut query = sqlx::query_as::<_, EnergyDetailRow>(&sql);
    for val in bind_values {
        query = query.bind(val);
    }
    query.fetch_all(pool).await
}

/// 构建导出工作簿（表头 + 数据行）
fn build_energy_workbook(
    rows: &[EnergyDetailRow],
) -> Result<rust_xlsxwriter::Workbook, Box<dyn std::error::Error + Send + Sync>> {
    let mut workbook = rust_xlsxwriter::Workbook::new();
    let sheet = workbook.add_worksheet();
    sheet.set_name("能耗统计")?;

    let headers = [
        "日期", "柜子ID", "柜子名称", "所属项目", "能耗(Wh)", "充电次数",
    ];
    for (col, header) in headers.iter().enumerate() {
        sheet.write_string(0, col as u16, *header)?;
    }

    for (row_idx, record) in rows.iter().enumerate() {
        let row = (row_idx + 1) as u32;
        sheet.write_string(row, 0, record.stat_date.to_string())?;
        sheet.write_number(row, 1, record.cabinet_id as f64)?;
        sheet.write_string(row, 2, record.cabinet_name.as_deref().unwrap_or("-"))?;
        sheet.write_string(row, 3, record.project_name.as_deref().unwrap_or("-"))?;
        sheet.write_number(row, 4, record.total_energy.unwrap_or(0) as f64)?;
        sheet.write_number(row, 5, record.charge_count.unwrap_or(0) as f64)?;
    }

    Ok(workbook)
}

/// 将导出任务标记为完成并记录文件路径
async fn mark_task_completed(
    pool: &sqlx::MySqlPool,
    task_id: i64,
    file_path: &str,
) -> Result<(), sqlx::Error> {
    sqlx::query(
        "UPDATE download_tasks SET status = 2, progress = 100, file_path = ?, \
         error_message = NULL, completed_at = NOW() WHERE id = ?"
    )
    .bind(file_path)
    .bind(task_id)
    .execute(pool)
    .await?;

    Ok(())
}

/// 后台异步生成能耗 Excel 文件
async fn generate_energy_excel(
    pool: sqlx::MySqlPool,
    task_id: i64,
) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    // 更新状态为处理中
    sqlx::query("UPDATE download_tasks SET status = 1 WHERE id = ?")
        .bind(task_id)
        .execute(&pool)
        .await?;

    // 获取查询参数
    let (file_name, params) = load_export_task(&pool, task_id).await?;

    // 组织过滤（非总管理员）+ 查询能耗明细
    let (where_clause, bind_values) = build_export_where(&params);
    let rows = fetch_energy_detail_rows(&pool, &where_clause, &bind_values).await?;

    // 更新进度 50%
    sqlx::query("UPDATE download_tasks SET progress = 50 WHERE id = ?")
        .bind(task_id)
        .execute(&pool)
        .await?;

    // 生成 Excel
    let mut workbook = build_energy_workbook(&rows)?;

    // 保存文件
    let file_dir = "./exports";
    tokio::fs::create_dir_all(file_dir).await?;
    let file_path = format!("{}/{}", file_dir, file_name);
    workbook.save(&file_path)?;

    // 更新任务状态为完成
    mark_task_completed(&pool, task_id, &file_path).await?;

    tracing::info!("能耗统计导出完成 task_id={} file={}", task_id, file_path);
    Ok(())
}

// ---------------------------------------------------------------------------
// 单元测试
// ---------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use super::*;

    /// 趋势 `range` 夹紧：负数会让 `DATE_SUB(CURDATE(), INTERVAL -5 DAY)` 变成"未来 5 天"，
    /// 0 会让窗口退化成"仅今天零点以后"，超大值会全表扫描。
    #[test]
    fn test_clamp_range_bounds_illegal_values() {
        assert_eq!(clamp_range(30), 30, "合法值应原样保留");
        assert_eq!(clamp_range(0), TREND_RANGE_MIN, "0 应被抬到下限");
        assert_eq!(clamp_range(-5), TREND_RANGE_MIN, "负数应被抬到下限");
        assert_eq!(clamp_range(999_999), TREND_RANGE_MAX, "超大值应被压到上限");
    }

    /// 时间窗口片段必须只按 `start_time` 归属（不得出现 `end_time` / `stat_date`），
    /// 且今日/本月都必须是半开区间（索引可用的写法）。
    #[test]
    fn test_time_window_uses_start_time_half_open_ranges() {
        assert!(time_window::TODAY.contains("cr.start_time >= CURDATE()"));
        assert!(time_window::TODAY.contains("cr.start_time < CURDATE() + INTERVAL 1 DAY"));
        assert!(time_window::THIS_MONTH.contains("cr.start_time >= DATE_FORMAT(CURDATE(), '%Y-%m-01')"));
        assert!(time_window::THIS_MONTH.contains("INTERVAL 1 MONTH"));
        // 导出结束日期必须"含当天" ⇒ 用 < 次日 00:00:00，而不是 <= 当天（会丢掉当天全部记录）
        assert_eq!(time_window::BEFORE_NEXT_DAY, "cr.start_time < DATE_ADD(?, INTERVAL 1 DAY)");

        for window in [time_window::TODAY, time_window::THIS_MONTH] {
            assert!(!window.contains("end_time"), "口径必须是 start_time：{}", window);
            assert!(!window.contains("stat_date"), "不得再引用 energy_stats.stat_date：{}", window);
        }
    }

    /// 导出 WHERE 构建：列名必须指向 charge_records（`cr.`），
    /// 日期条件必须落在 `cr.start_time`，且参数一律走占位符（不做字符串拼接）。
    #[test]
    fn test_build_export_clause_targets_charge_records() {
        let (clause, binds) = build_export_clause(
            Some(7),
            Some(3),
            Some("2026-01-01"),
            Some("2026-01-31"),
        );
        assert!(clause.starts_with("WHERE "), "非空条件应带 WHERE：{}", clause);
        assert!(clause.contains("cr.cabinet_id = ?"), "柜子过滤应指向 cr：{}", clause);
        assert!(clause.contains("c.project_id = ?"), "项目过滤应指向 cabinets：{}", clause);
        assert!(clause.contains("cr.start_time >= ?"), "起始日期应落在 cr.start_time：{}", clause);
        assert!(clause.contains(time_window::BEFORE_NEXT_DAY), "结束日期应含当天：{}", clause);
        assert!(!clause.contains("energy_stats"), "不得再引用 energy_stats：{}", clause);
        assert_eq!(binds, vec!["7", "3", "2026-01-01", "2026-01-31"]);
    }

    /// 无条件时应返回空子句（由 `fetch_energy_detail_rows` 自己补 `start_time IS NOT NULL` 兜底）
    #[test]
    fn test_build_export_clause_empty_when_no_filters() {
        let (clause, binds) = build_export_clause(None, None, None, None);
        assert!(clause.is_empty());
        assert!(binds.is_empty());
    }

    /// 组织隔离：非总管理员 + 有组织 ⇒ 必须追加 `cr.cabinet_id IN (...)` 子查询并带上组织 ID；
    /// 非总管理员 + 无组织 ⇒ 必须追加 `1=0` 空集（**绝不退化成"全部"**）。
    #[test]
    fn test_build_export_where_keeps_org_isolation() {
        // 总管理员：不加任何组织条件
        let (clause, binds) = build_export_where(&json!({"role_level": 2}));
        assert!(clause.is_empty(), "总管理员不应有额外条件：{}", clause);
        assert!(binds.is_empty());

        // 组织管理员：追加组织子查询
        let (clause, binds) = build_export_where(&json!({"role_level": 1, "org_id": 42}));
        assert!(
            clause.contains("cr.cabinet_id IN (SELECT c.id FROM cabinets c JOIN projects p ON c.project_id = p.id WHERE p.organization_id = ?)"),
            "组织隔离条件丢失：{}",
            clause
        );
        assert_eq!(binds, vec!["42"]);

        // 客户侧账号但无组织：空集
        let (clause, binds) = build_export_where(&json!({"role_level": 0}));
        assert_eq!(clause, "WHERE 1=0");
        assert!(binds.is_empty());

        // 已有条件时组织条件用 AND 拼接（不能覆盖原有筛选）
        let (clause, _) = build_export_where(&json!({"cabinet_id": 9, "role_level": 1, "org_id": 42}));
        assert!(clause.contains("cr.cabinet_id = ? AND cr.cabinet_id IN ("), "拼接方式错误：{}", clause);
    }

    /// 电费估算口径：`energy` 单位 Wh，单价 0.80 元/kWh ⇒ 1000 Wh = 0.80 元。
    #[test]
    fn test_estimated_cost_unit_is_wh_times_80_cent_per_kwh() {
        let month_energy_wh: i64 = 1000;
        let cost = (month_energy_wh * COST_PER_WH_CENT / 1000) as f64 / 100.0;
        assert!((cost - 0.80).abs() < f64::EPSILON, "1000Wh 应为 0.8 元，实际 {}", cost);

        // 22 Wh（联调实测值）≈ 0.0176 元，不应被当成 22 kWh（那会是 17.6 元）
        let small = (22_i64 * COST_PER_WH_CENT / 1000) as f64 / 100.0;
        assert!(small < 0.02, "22Wh 不应被当成 22kWh：{}", small);
    }
}