use chrono::{DateTime, FixedOffset};
use rocket::fs::TempFile;
use rocket::tokio::io::{AsyncReadExt, BufReader};
use rocket_db_pools::Connection;
use serde::Serialize;
use sqlx::types::Decimal;
use tracing::error;

use crate::imaging;
use crate::Database;

#[derive(Debug, Serialize)]
pub struct Receipt {
    pub id: i32,
    pub date: DateTime<FixedOffset>,
    pub vendor: String,
    pub amount: Decimal,
    pub notes: Option<String>,
    pub filename: String,
    pub image: Vec<u8>,
}

#[derive(Debug, Serialize)]
pub struct ReceiptJson {
    pub id: i32,
    pub date: DateTime<FixedOffset>,
    pub vendor: String,
    pub amount: Decimal,
    pub notes: Option<String>,
    pub filename: String,
}

#[derive(rocket::FromForm)]
pub struct ReceiptPostForm<'r> {
    pub transaction: Option<String>,
    pub date: String,
    pub vendor: String,
    pub amount: String,
    pub is_restaurant: Option<bool>,
    pub notes: String,
    pub photo: TempFile<'r>,
}

pub struct ReceiptPostData {
    pub date: DateTime<FixedOffset>,
    pub vendor: String,
    pub amount: Decimal,
    pub is_restaurant: bool,
    pub notes: String,
    pub filename: String,
    pub photo: Vec<u8>,
}

#[derive(Debug, thiserror::Error)]
pub enum ReceiptPostFormError {
    #[error("Invalid date: {0}")]
    Date(#[from] chrono::format::ParseError),
    #[error("Invalid amount: {0}")]
    Amount(#[from] rust_decimal::Error),
    #[error("Error reading photo: {0}")]
    Photo(#[from] std::io::Error),
    #[error("Unsupported image type")]
    UnsupportedImageFormat,
}

#[derive(Serialize)]
#[serde(rename_all = "lowercase")]
pub enum AddReceiptResponse {
    Success(ReceiptJson),
    Error(String),
}

#[derive(Serialize)]
#[serde(rename_all = "lowercase")]
pub enum DeleteReceiptResponse {
    Success,
    Error(String),
}

impl ReceiptPostData {
    pub async fn from_form(
        form: &ReceiptPostForm<'_>,
    ) -> Result<Self, ReceiptPostFormError> {
        let date = DateTime::parse_from_str(
            &format!("{} 00:00:00 +0000", form.date),
            "%Y-%m-%d %H:%M:%S %z",
        )?;
        let vendor = form.vendor.clone();
        use rust_decimal::prelude::FromStr;
        let amount = Decimal::from_str(&form.amount)?;
        let is_restaurant = form.is_restaurant.unwrap_or_default();
        let notes = form.notes.clone();
        let stream = form.photo.open().await?;
        let mut reader = BufReader::new(stream);
        let mut photo = Vec::new();
        reader.read_to_end(&mut photo).await?;
        let extension = match imaging::get_type(&photo).as_deref() {
            Some("BMP") => "bmp",
            Some("JPEG") => "jpg",
            Some("PDF") => "pdf",
            Some("PNG") => "png",
            Some("PPM") => "ppm",
            Some("TIFF") => "tiff",
            Some("WEBP") => "webp",
            Some(f) => {
                error!("Unsupported image format: {}", f);
                return Err(ReceiptPostFormError::UnsupportedImageFormat);
            },
            None => {
                return Err(ReceiptPostFormError::UnsupportedImageFormat);
            },
        };
        let filename = form
            .photo
            .name()
            .map(|n| format!("{}.{}", n, extension))
            .unwrap_or("photo.jpg".into());
        Ok(Self {
            date,
            vendor,
            amount,
            is_restaurant,
            notes,
            filename,
            photo,
        })
    }
}

pub struct ReceiptsRepository {
    conn: Connection<Database>,
}

impl ReceiptsRepository {
    pub fn new(conn: Connection<Database>) -> Self {
        Self { conn }
    }

    pub async fn list_receipts(
        &mut self,
    ) -> Result<Vec<ReceiptJson>, sqlx::Error> {
        sqlx::query_file_as!(ReceiptJson, "sql/receipts/list-receipts.sql")
            .fetch_all(&mut **self.conn)
            .await
    }

    pub async fn add_receipt(
        &mut self,
        data: &ReceiptPostData,
    ) -> Result<ReceiptJson, sqlx::Error> {
        let result = sqlx::query_file_as!(
            ReceiptJson,
            "sql/receipts/insert-receipt.sql",
            data.vendor,
            data.date,
            data.amount,
            data.notes,
            data.filename,
            data.photo,
        )
        .fetch_one(&mut **self.conn)
        .await?;
        Ok(result)
    }

    pub async fn get_receipt(
        &mut self,
        id: i32,
    ) -> Result<ReceiptJson, sqlx::Error> {
        sqlx::query_file_as!(ReceiptJson, "sql/receipts/get-receipt.sql", id,)
            .fetch_one(&mut **self.conn)
            .await
    }
    pub async fn get_receipt_photo(
        &mut self,
        id: i32,
    ) -> Result<(String, Vec<u8>), sqlx::Error> {
        let result = sqlx::query!(
            "SELECT filename, image FROM receipts WHERE id = $1",
            id,
        )
        .fetch_one(&mut **self.conn)
        .await?;
        Ok((result.filename, result.image))
    }

    pub async fn delete_receipt(
        &mut self,
        id: i32,
    ) -> Result<(), sqlx::Error> {
        sqlx::query_as!(ReceiptJson, "DELETE FROM receipts WHERE id = $1", id)
            .execute(&mut **self.conn)
            .await?;
        Ok(())
    }
}