use std::ffi::OsStr;
use std::fs::{read_dir, remove_file};
use std::io::{BufWriter, Write};

use axum::async_trait;
use maud::html;
use sqlx::SqlitePool;

use crate::error::AppError;
use crate::db::product::Product;
use crate::handlers::frontend_builder::PageBuilder;

use super::product::ProductMarker;
use super::ProductDatabaseHandler;


#[derive(Debug, serde::Serialize, sqlx::FromRow)]
pub struct Story {
    pub id: i64,
    pub language: String,
    pub pdf: Vec<u8>,
    pub epub: Vec<u8>,
    pub pid: i64,
}

impl ProductMarker for Story {
    fn product_id(&self) -> i64 {
        self.pid
    }
}

pub async fn synchronize_story_files(pool: &SqlitePool) -> Result<(), anyhow::Error> {
    for entry in read_dir("static")? {
        let path = entry?.path();
        if path.extension().is_some_and(|ext| ext == OsStr::new("pdf") || ext == OsStr::new("epub")) {
            remove_file(path)?;
        }
    }
    let results = sqlx::query!("SELECT p.name, s.pdf, s.epub FROM story s INNER JOIN product p ON s.pid = p.id").fetch_all(pool).await?;
    for result in results.iter() {
        let mut pdf_filename = format!("{}.pdf", result.name).to_lowercase();
        pdf_filename.retain(|c| !c.is_whitespace());

        let file = std::fs::File::create_new(format!("static/{}", pdf_filename))?;
        BufWriter::new(file).write_all(&result.pdf.to_vec())?;

        let mut epub_filename = format!("{}.epub", result.name).to_lowercase();
        epub_filename.retain(|c| !c.is_whitespace());

        let file = std::fs::File::create_new(format!("static/{}", epub_filename))?;
        BufWriter::new(file).write_all(&result.epub.to_vec())?;
    }
    Ok(())
}

#[async_trait]
impl ProductDatabaseHandler for Story {
    async fn get_all(pool: &SqlitePool) -> Result<Vec<Self>, AppError>
    where
        Self: Sized,
    {
        Ok(sqlx::query_as!(Story, "SELECT * FROM story")
            .fetch_all(pool)
            .await?)
    }

    async fn post(&self, pool: &SqlitePool, name: String, description: String) -> Result<Self, AppError>
    where
        Self: Sized,
    {
        let time = std::time::SystemTime::now();
        let uploaddate = time.duration_since(std::time::UNIX_EPOCH)?.as_millis() as i64;

        let mut tx = pool.begin().await?;
        let product = sqlx::query_as!(
            Product, 
            "INSERT INTO product (name, description, uploaddate, updatedate) VALUES ($1, $2, $3, $4) RETURNING id, name, description, uploaddate, updatedate", 
            name, 
            description,
            uploaddate,
            uploaddate)
            .fetch_one(&mut *tx)
            .await?;

        let story = sqlx::query_as!(
            Story,
            "INSERT INTO story (language, pdf, epub, pid) VALUES ($1, $2, $3, $4) RETURNING id, language, pdf, epub, pid", 
            self.language,
            self.pdf,
            self.epub,
            product.id)
            .fetch_one(&mut *tx)
            .await?;

        tx.commit().await?;

        Ok(story)
    }
}

impl PageBuilder for Story {
   fn page_title() -> String {
        "Stories".to_string()
    } 

   // TODO: Add pdf and epub download link + language info
   fn product_specific_card_content(&self) -> maud::Markup {
       html!(
           span {
           }
       )
   }
}