use axum::{Json, extract::{Path, Query, State}, http::StatusCode, response::IntoResponse};
use serde::Deserialize;
use std::collections::HashMap;
use sqlx::types::Json as SqlxJson;
use uuid::Uuid;
use validator::Validate;

use crate::model::Page;
use crate::util::response::ApiErr;
use crate::AppState;

#[derive(Deserialize, Validate)]
pub struct GetPageListQuery {
    #[validate(length(min = 1, max = 100))]
    pub name: Option<String>,
}

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

    let pages: Vec<Page> = if let Some(name) = query.name {
        sqlx::query_as::<_, Page>(
            r#"
            SELECT * FROM page
            WHERE name ILIKE $1
            ORDER BY created_at
            "#,
        )
        .bind(format!("%{}%", name))
        .fetch_all(pool)
        .await?
    } else {
        sqlx::query_as::<_, Page>(
            r#"SELECT * FROM page ORDER BY created_at"#,
        )
        .fetch_all(pool)
        .await?
    };

    Ok(Json(pages))
}

pub async fn get_page(
    State(state): State<AppState>,
    Path(page_id): Path<Uuid>,
) -> Result<impl IntoResponse, ApiErr> {
    let page = sqlx::query_as::<_, Page>("SELECT * FROM page WHERE id = $1")
        .bind(page_id)
        .fetch_optional(&state.pool)
        .await?;

    match page {
        Some(p) => Ok(Json(p)),
        None => Err(ApiErr::NotFound("Page not found".to_string(), None)),
    }
}

#[derive(Debug, Deserialize, Validate)]
pub struct CreatePageReq {
    #[validate(length(min = 1, max = 100))]
    pub name: String,
    pub data: HashMap<String, Uuid>,
}

#[derive(Debug, Deserialize, Validate)]
pub struct UpdatePageReq {
    #[validate(length(min = 1, max = 100))]
    pub name: Option<String>,
    pub data: Option<HashMap<String, Uuid>>,
}

pub async fn create_page(
    State(state): State<AppState>,
    Json(payload): Json<CreatePageReq>,
) -> Result<impl IntoResponse, ApiErr> {
    payload.validate()?;

    let page_id = sqlx::query_scalar::<_, Uuid>(
        r#"
        INSERT INTO page (name, data)
        VALUES ($1, $2)
        RETURNING id
        "#,
    )
    .bind(&payload.name)
    .bind(SqlxJson(payload.data))
    .fetch_one(&state.pool)
    .await?;

    Ok((StatusCode::CREATED, Json(serde_json::json!({
        "id": page_id,
        "ok_msg": "Page created successfully"
    }))))
}

pub async fn update_page(
    State(state): State<AppState>,
    Path(page_id): Path<Uuid>,
    Json(payload): Json<UpdatePageReq>,
) -> Result<impl IntoResponse, ApiErr> {
    payload.validate()?;

    let exists = sqlx::query("SELECT 1 FROM page WHERE id = $1")
        .bind(page_id)
        .fetch_optional(&state.pool)
        .await?;
    if exists.is_none() {
        return Err(ApiErr::NotFound("Page not found".to_string(), None));
    }

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

    let mut updates = Vec::new();
    let mut param_count = 1;

    if payload.name.is_some() {
        updates.push(format!("name = ${}", param_count));
        param_count += 1;
    }
    if payload.data.is_some() {
        updates.push(format!("data = ${}", param_count));
        param_count += 1;
    }

    updates.push("updated_at = NOW()".to_string());

    let sql = format!(
        r#"UPDATE page SET {} WHERE id = ${}"#,
        updates.join(", "),
        param_count
    );

    let mut query = sqlx::query(&sql);
    if let Some(name) = payload.name {
        query = query.bind(name);
    }
    if let Some(data) = payload.data {
        query = query.bind(SqlxJson(data));
    }
    query = query.bind(page_id);

    query.execute(&state.pool).await?;

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

pub async fn delete_page(
    State(state): State<AppState>,
    Path(page_id): Path<Uuid>,
) -> Result<impl IntoResponse, ApiErr> {
    let result = sqlx::query("DELETE FROM page WHERE id = $1")
        .bind(page_id)
        .execute(&state.pool)
        .await?;

    if result.rows_affected() == 0 {
        return Err(ApiErr::NotFound("Page not found".to_string(), None));
    }

    Ok(StatusCode::NO_CONTENT)
}