use axum::{Json, extract::{Path, Query, State}, http::HeaderMap, response::IntoResponse};
use serde::{Deserialize, Serialize};
use uuid::Uuid;
use validator::Validate;
use sqlx::{Row, QueryBuilder};

use crate::util::{response::ApiErr, pagination::{PaginatedResponse, PaginationParams}};

use crate::{
    AppState,
    model::{Node, Point},
};

/// List all points.
#[derive(Deserialize, Validate)]
pub struct GetPointListQuery {
    pub source_id: Option<Uuid>,
    #[serde(flatten)]
    pub pagination: PaginationParams,
}

#[derive(Serialize)]
pub struct PointWithMonitor {
    #[serde(flatten)]
    pub point: Point,
    pub point_monitor: Option<crate::telemetry::PointMonitorInfo>,
}

pub async fn get_point_list(
    State(state): State<AppState>,
    Query(query): Query<GetPointListQuery>,
) -> Result<impl IntoResponse, ApiErr> {
    query.validate()?;
    let pool = &state.pool;

    // 获取总数
    let total = crate::service::get_points_count(pool, query.source_id).await?;

    // 获取分页数据
    let points = crate::service::get_points_paginated(
        pool,
        query.source_id,
        query.pagination.page_size,
        query.pagination.offset(),
    ).await?;

    let monitor_guard = state
        .connection_manager
        .get_point_monitor_data_read_guard()
        .await;

    let data: Vec<PointWithMonitor> = points
        .into_iter()
        .map(|point| {
            let point_monitor = monitor_guard
                .get(&point.id)
                .cloned();
            PointWithMonitor { point, point_monitor }
        })
        .collect();

    let response = PaginatedResponse::new(data, total, query.pagination.page, query.pagination.page_size);

    Ok(Json(response))
}
/// Get a point by id.
pub async fn get_point(
    State(state): State<AppState>,
    Path(point_id): Path<Uuid>,
) -> Result<impl IntoResponse, ApiErr> {
    let pool = &state.pool;
    let point = crate::service::get_point_by_id(pool, point_id).await?;

    Ok(Json(point))
}


/// Request payload for updating editable point fields.
#[derive(Deserialize, Validate)]
pub struct UpdatePointReq {
    pub name: Option<String>,
    pub description: Option<String>,
    pub unit: Option<String>,
    pub tag_id: Option<Uuid>,
}

/// Request payload for batch setting point tags.
#[derive(Deserialize, Validate)]
pub struct BatchSetPointTagsReq {
    pub point_ids: Vec<Uuid>,
    pub tag_id: Option<Uuid>,
}

/// Update point metadata (name/description/unit only).
pub async fn update_point(
    State(state): State<AppState>,
    Path(point_id): Path<Uuid>,
    Json(payload): Json<UpdatePointReq>,
) -> Result<impl IntoResponse, ApiErr> {
    payload.validate()?;

    let pool = &state.pool;

    if payload.name.is_none() && payload.description.is_none() && payload.unit.is_none() && payload.tag_id.is_none() {
        return Ok(Json(serde_json::json!({"ok_msg": "No fields to update"})));
    }

    // If tag_id is provided, ensure tag exists.
    if let Some(tag_id) = payload.tag_id {
        let tag_exists = sqlx::query(
            r#"SELECT 1 FROM tag WHERE id = $1"#,
        )
        .bind(tag_id)
        .fetch_optional(pool)
        .await?
        .is_some();

        if !tag_exists {
            return Err(ApiErr::NotFound("Tag not found".to_string(), None));
        }
    }

    // Ensure target point exists.
    let existing_point = sqlx::query_as::<_, Point>(
        r#"SELECT * FROM point WHERE id = $1"#,
    )
    .bind(point_id)
    .fetch_optional(pool)
    .await?;
    if existing_point.is_none() {
        return Err(ApiErr::NotFound("Point not found".to_string(), None));
    }

    let mut qb = QueryBuilder::new("UPDATE point SET ");
    let mut sep = qb.separated(", ");

    if let Some(name) = &payload.name {
        sep.push("name = ").push_bind(name);
    }
    if let Some(description) = &payload.description {
        sep.push("description = ").push_bind(description);
    }
    if let Some(unit) = &payload.unit {
        sep.push("unit = ").push_bind(unit);
    }
    if let Some(tag_id) = &payload.tag_id {
        sep.push("tag_id = ").push_bind(tag_id);
    }

    sep.push("updated_at = NOW()");

    qb.push(" WHERE id = ").push_bind(point_id);
    qb.build().execute(pool).await?;

    Ok(Json(serde_json::json!({"ok_msg": "Point updated successfully"})))
}

/// Batch set point tags.
pub async fn batch_set_point_tags(
    State(state): State<AppState>,
    Json(payload): Json<BatchSetPointTagsReq>,
) -> Result<impl IntoResponse, ApiErr> {
    payload.validate()?;

    if payload.point_ids.is_empty() {
        return Err(ApiErr::BadRequest("point_ids cannot be empty".to_string(), None));
    }

    let pool = &state.pool;

    // If tag_id is provided, ensure tag exists.
    if let Some(tag_id) = payload.tag_id {
        let tag_exists = sqlx::query(
            r#"SELECT 1 FROM tag WHERE id = $1"#,
        )
        .bind(tag_id)
        .fetch_optional(pool)
        .await?
        .is_some();

        if !tag_exists {
            return Err(ApiErr::NotFound("Tag not found".to_string(), None));
        }
    }

    // Check which points exist
    let existing_points: Vec<Uuid> = sqlx::query(
        r#"SELECT id FROM point WHERE id = ANY($1)"#,
    )
    .bind(&payload.point_ids)
    .fetch_all(pool)
    .await?
    .into_iter()
    .map(|row: sqlx::postgres::PgRow| row.get::<Uuid, _>("id"))
    .collect();

    if existing_points.is_empty() {
        return Err(ApiErr::NotFound("No valid points found".to_string(), None));
    }

    // Update tag_id for all existing points
    let result = sqlx::query(
        r#"UPDATE point SET tag_id = $1, updated_at = NOW() WHERE id = ANY($2)"#,
    )
    .bind(payload.tag_id)
    .bind(&existing_points)
    .execute(pool)
    .await?;

    Ok(Json(serde_json::json!({
        "ok_msg": "Point tags updated successfully",
        "updated_count": result.rows_affected()
    })))
}

/// Delete one point by id.
pub async fn delete_point(
    State(state): State<AppState>,
    Path(point_id): Path<Uuid>,
) -> Result<impl IntoResponse, ApiErr> {
    let pool = &state.pool;

    let source_id = {
        let grouped = crate::service::get_points_grouped_by_source(pool, &[point_id]).await?;
        grouped.keys().next().copied()
    };

    // Ensure target point exists.
    let existing_point = sqlx::query_as::<_, Point>(
        r#"SELECT * FROM point WHERE id = $1"#,
    )
    .bind(point_id)
    .fetch_optional(pool)
    .await?;
    if existing_point.is_none() {
        return Err(ApiErr::NotFound("Point not found".to_string(), None));
    }

    // Delete point.
    sqlx::query(
        r#"delete from point WHERE id = $1"#,
    )
    .bind(point_id)
    .execute(pool)
    .await?;

    if let Some(source_id) = source_id {
        if let Err(e) = state
            .event_manager
            .send(crate::event::ReloadEvent::PointDeleteBatch {
                source_id,
                point_ids: vec![point_id],
            })
        {
            tracing::error!("Failed to send PointDeleteBatch event: {}", e);
        }
    }

    Ok(Json(serde_json::json!({"ok_msg": "Point deleted successfully"})))
}

#[derive(Deserialize, Validate)]
/// Request payload for batch point creation from node ids.
pub struct BatchCreatePointsReq {
    pub node_ids: Vec<Uuid>,
}

#[derive(Serialize)]
/// Response payload for batch point creation.
pub struct BatchCreatePointsRes {
    pub success_count: usize,
    pub failed_count: usize,
    pub failed_node_ids: Vec<Uuid>,
    pub created_point_ids: Vec<Uuid>,
}

/// Batch create points by node ids.
pub async fn batch_create_points(
    State(state): State<AppState>,
    Json(payload): Json<BatchCreatePointsReq>,
) -> Result<impl IntoResponse, ApiErr> {
    payload.validate()?;

    let pool = &state.pool;

    if payload.node_ids.is_empty() {
        return Err(ApiErr::BadRequest("node_ids cannot be empty".to_string(), None));
    }

    let mut success_count = 0;
    let mut failed_count = 0;
    let mut failed_node_ids = Vec::new();
    let mut created_point_ids = Vec::new();

    // Use one transaction for the full batch.
    let mut tx = pool.begin().await?;

    for node_id in payload.node_ids {
        // Ensure node exists.
        let node_exists = sqlx::query(
            r#"SELECT 1 FROM node WHERE id = $1"#,
        )
        .bind(node_id)
        .fetch_optional(&mut *tx)
        .await?
        .is_some();

        if !node_exists {
            failed_count += 1;
            failed_node_ids.push(node_id);
            continue;
        }

        // Skip nodes that already have a point.
        let point_exists = sqlx::query(
            r#"SELECT 1 FROM point WHERE node_id = $1"#,
        )
        .bind(node_id)
        .fetch_optional(&mut *tx)
        .await?
        .is_some();

        if point_exists {
            continue;
        }

        // Use node browse_name as default point name.
        let node_info = sqlx::query_as::<_, Node>(
            r#"SELECT * FROM node WHERE id = $1"#,
        )
        .bind(node_id)
        .fetch_optional(&mut *tx)
        .await?;

        let name = match node_info {
            Some(node) => node.browse_name.clone(),
            None => format!("Point_{}", node_id),
        };

        let new_id = Uuid::new_v4();

        sqlx::query(
            r#"
            INSERT INTO point (id, node_id, name)
            VALUES ($1, $2, $3)
            "#
        )
        .bind(new_id)
        .bind(node_id)
        .bind(&name)
        .execute(&mut *tx)
        .await?;

        success_count += 1;
        created_point_ids.push(new_id);
    }

    // Commit the transaction.
    tx.commit().await?;

    // Emit grouped create events by source.
    if !created_point_ids.is_empty() {
        let grouped = crate::service::get_points_grouped_by_source(pool, &created_point_ids).await?;
        for (source_id, points) in grouped {
            let point_ids: Vec<Uuid> = points.into_iter().map(|p| p.point_id).collect();
            if let Err(e) = state
                .event_manager
                .send(crate::event::ReloadEvent::PointCreateBatch { source_id, point_ids })
            {
                tracing::error!("Failed to send PointCreateBatch event: {}", e);
            }
        }
    }

    Ok(Json(BatchCreatePointsRes {
        success_count,
        failed_count,
        failed_node_ids,
        created_point_ids,
    }))
}

#[derive(Deserialize, Validate)]
/// Request payload for batch point deletion.
pub struct BatchDeletePointsReq {
    pub point_ids: Vec<Uuid>,
}

#[derive(Serialize)]
/// Response payload for batch point deletion.
pub struct BatchDeletePointsRes {
    pub deleted_count: u64,
}

/// Batch delete points and emit grouped delete events by source.
pub async fn batch_delete_points(
    State(state): State<AppState>,
    Json(payload): Json<BatchDeletePointsReq>,
) -> Result<impl IntoResponse, ApiErr> {
    payload.validate()?;

    if payload.point_ids.is_empty() {
        return Err(ApiErr::BadRequest("point_ids cannot be empty".to_string(), None));
    }

    let pool = &state.pool;
    let point_ids = payload.point_ids;

    let grouped = crate::service::get_points_grouped_by_source(pool, &point_ids).await?;
    let existing_point_ids: Vec<Uuid> = grouped
        .values()
        .flat_map(|points| points.iter().map(|p| p.point_id))
        .collect();

    if existing_point_ids.is_empty() {
        return Ok(Json(BatchDeletePointsRes { deleted_count: 0 }));
    }

    let result = sqlx::query(
        r#"DELETE FROM point WHERE id = ANY($1)"#,
    )
    .bind(&existing_point_ids)
    .execute(pool)
    .await?;

    for (source_id, points) in grouped {
        let ids: Vec<Uuid> = points.into_iter().map(|p| p.point_id).collect();
        if let Err(e) = state
            .event_manager
            .send(crate::event::ReloadEvent::PointDeleteBatch {
                source_id,
                point_ids: ids,
            })
        {
            tracing::error!("Failed to send PointDeleteBatch event: {}", e);
        }
    }

    Ok(Json(BatchDeletePointsRes {
        deleted_count: result.rows_affected(),
    }))
}





pub async fn batch_set_point_value(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(payload): Json<crate::connection::BatchSetPointValueReq>,
) -> Result<impl IntoResponse, ApiErr> {
    let write_key = headers
        .get("X-Write-Key")
        .and_then(|v| v.to_str().ok())
        .unwrap_or_default();

    if !state.config.verify_write_key(write_key) {
        return Err(ApiErr::Forbidden(
            "write permission denied".to_string(),
            Some(serde_json::json!({
                "hint": "set WRITE_API_KEY (or legacy WRITE_KEY) and pass header X-Write-Key"
            })),
        ));
    }

    let result = state.connection_manager.write_point_values_batch(payload)
        .await
        .map_err(|e| ApiErr::Internal(e, None))?;
    Ok(Json(result))
}