use rocket::http::Status;
use rocket::serde::{self, json::Json, Deserialize, Serialize};
use rocket_db_pools::Connection;
use sqlx::types::JsonValue;
use sqlx::Executor;
use tracing::error;
use url::Url;
use uuid::Uuid;

use crate::feed_utils::fetch_feed;
use crate::user::AuthenticatedUser;
use crate::Db;

#[derive(Debug, Serialize)]
#[serde(crate = "rocket::serde")]
pub struct Feed {
    pub feed_id: Uuid,
    pub name: String,
    pub url: Url,
    pub user_id: Uuid,
    pub added_time: chrono::DateTime<chrono::Utc>,
    pub last_checked_time: chrono::DateTime<chrono::Utc>,
    pub categorization: Vec<String>,
}

impl Feed {
    pub fn new(name: String, url: Url, user_id: Uuid) -> Self {
        let now = chrono::Utc::now();
        Feed {
            feed_id: Uuid::new_v4(),
            name,
            url,
            user_id,
            added_time: now,
            last_checked_time: chrono::DateTime::UNIX_EPOCH,
            categorization: Vec::new(),
        }
    }

    pub async fn write_to_database<'a, E>(&self, executor: E) -> sqlx::Result<()>
    where
        E: Executor<'a, Database = sqlx::Sqlite>,
    {
        // Convert categorization to JSON value
        let categorization_json = serde::json::to_value(&self.categorization).map_err(|e| {
            error!("Failed to serialize categorization: {}", e);
            sqlx::Error::Decode(Box::new(e))
        })?;

        let feed_id_str = self.feed_id.to_string();
        let user_id_str = self.user_id.to_string();
        let added_time_str = self.added_time.to_rfc3339();
        let last_checked_time_str = self.last_checked_time.to_rfc3339();
        let url_str = self.url.as_str();
        let categorization_str = categorization_json.to_string();

        sqlx::query!(
            r#"
            INSERT INTO feeds (feed_id, name, url, user_id, added_time, last_checked_time, categorization) 
            VALUES (?, ?, ?, ?, ?, ?, json(?))
            "#,
            feed_id_str,
            self.name,
            url_str,
            user_id_str,
            added_time_str,
            last_checked_time_str,
            categorization_str
        )
        .execute(executor)
        .await?;

        Ok(())
    }
}

#[derive(Debug, Deserialize)]
#[serde(crate = "rocket::serde")]
pub struct NewFeed {
    pub url: Url,
    #[serde(default)]
    pub categorization: Vec<String>,
}

#[post("/feeds", data = "<new_feed>")]
pub async fn create_feed(
    mut db: Connection<Db>,
    new_feed: Json<NewFeed>,
    user: AuthenticatedUser,
) -> Result<Json<Feed>, Status> {
    let new_feed = new_feed.into_inner();

    if !new_feed.url.scheme().eq("http") && !new_feed.url.scheme().eq("https") {
        eprintln!("Invalid URL scheme: {}", new_feed.url.scheme());
        return Err(Status::UnprocessableEntity);
    }

    let feed_data = fetch_feed(&new_feed.url)
        .await
        .map_err(|_| Status::UnprocessableEntity)?;

    // Use the feed title as the name, or URL if no title is available
    let name = feed_data.title.map(|t| t.content).unwrap_or_else(|| {
        new_feed
            .url
            .host_str()
            .map(|s| s.to_string())
            .unwrap_or_else(|| "<Unknown>".to_string())
    });

    let mut feed = Feed::new(name, new_feed.url, user.user_id);
    feed.categorization = new_feed.categorization;

    match feed.write_to_database(&mut **db).await {
        Ok(_) => Ok(Json(feed)),
        Err(e) => {
            eprintln!("Database error: {}", e);
            match e {
                sqlx::Error::Database(db_err) if db_err.is_unique_violation() => {
                    Err(Status::Conflict)
                }
                _ => Err(Status::InternalServerError),
            }
        }
    }
}

#[get("/feeds")]
pub async fn list_feeds(
    mut db: Connection<Db>,
    user: AuthenticatedUser,
) -> Result<Json<Vec<Feed>>, Status> {
    let user_id = user.user_id.to_string();

    let query = sqlx::query!(
        r#"
        SELECT 
            feed_id as "feed_id: String",
            name,
            url,
            user_id as "user_id: String",
            added_time as "added_time: chrono::DateTime<chrono::Utc>",
            last_checked_time as "last_checked_time: chrono::DateTime<chrono::Utc>",
            categorization as "categorization: JsonValue"
        FROM feeds
        WHERE user_id = ?
        ORDER BY name ASC
        "#,
        user_id
    )
    .fetch_all(&mut **db)
    .await
    .map_err(|e| {
        eprintln!("Database error: {}", e);
        Status::InternalServerError
    })?;

    let feeds = query
        .into_iter()
        .map(|row| {
            // Parse URL from string
            let url = Url::parse(&row.url).map_err(|e| {
                eprintln!("Failed to parse URL '{}': {}", row.url, e);
                Status::InternalServerError
            })?;

            // Parse categorization from JSON value
            let categorization: Vec<String> =
                serde::json::from_value(row.categorization).map_err(|e| {
                    eprintln!("Failed to parse categorization: {}", e);
                    Status::InternalServerError
                })?;
            let feed_id = Uuid::parse_str(&row.feed_id).map_err(|e| {
                eprintln!("Failed to parse feed_id UUID: {}", e);
                Status::InternalServerError
            })?;

            let user_id = Uuid::parse_str(&row.user_id).map_err(|e| {
                eprintln!("Failed to parse user_id UUID: {}", e);
                Status::InternalServerError
            })?;
            Ok(Feed {
                name: row.name,
                feed_id,
                url,
                user_id,
                added_time: row.added_time,
                last_checked_time: row.last_checked_time,
                categorization,
            })
        })
        .collect::<Result<Vec<_>, Status>>()?;

    Ok(Json(feeds))
}

#[delete("/feeds/<feed_id>")]
pub async fn delete_feed(mut db: Connection<Db>, feed_id: &str, user: AuthenticatedUser) -> Status {
    // Validate UUID format
    let feed_uuid = match Uuid::parse_str(feed_id) {
        Ok(uuid) => uuid,
        Err(_) => return Status::BadRequest,
    };

    let feed_id_str = feed_uuid.to_string();
    let user_id_str = user.user_id.to_string();

    let result = sqlx::query!(
        "DELETE FROM feeds WHERE feed_id = ? AND user_id = ?",
        feed_id_str,
        user_id_str
    )
    .execute(&mut **db)
    .await;

    match result {
        Ok(result) => {
            if result.rows_affected() > 0 {
                Status::NoContent
            } else {
                Status::NotFound
            }
        }
        Err(e) => {
            eprintln!("Database error: {}", e);
            Status::InternalServerError
        }
    }
}

#[get("/feeds/<feed_id>")]
pub async fn get_feed(
    mut db: Connection<Db>,
    feed_id: &str,
    user: AuthenticatedUser,
) -> Result<Json<Feed>, Status> {
    // Validate UUID format
    let feed_uuid = Uuid::parse_str(feed_id).map_err(|_| Status::BadRequest)?;
    let user_id = user.user_id.to_string();

    let row = sqlx::query!(
        r#"
        SELECT 
            feed_id as "feed_id: String",
            name,
            url,
            user_id as "user_id: String",
            added_time as "added_time: chrono::DateTime<chrono::Utc>",
            last_checked_time as "last_checked_time: chrono::DateTime<chrono::Utc>",
            categorization as "categorization: JsonValue"
        FROM feeds
        WHERE feed_id = ? AND user_id = ?
        "#,
        feed_uuid,
        user_id
    )
    .fetch_optional(&mut **db)
    .await
    .map_err(|e| {
        eprintln!("Database error: {}", e);
        Status::InternalServerError
    })?;

    let row = row.ok_or(Status::NotFound)?;

    // Parse URL from string
    let url = Url::parse(&row.url).map_err(|e| {
        eprintln!("Failed to parse URL '{}': {}", row.url, e);
        Status::InternalServerError
    })?;

    // Parse categorization from JSON value
    let categorization: Vec<String> = serde::json::from_value(row.categorization).map_err(|e| {
        eprintln!("Failed to parse categorization: {}", e);
        Status::InternalServerError
    })?;
    let user_id = Uuid::parse_str(&row.user_id).map_err(|e| {
        eprintln!("Failed to parse user_id UUID: {}", e);
        Status::InternalServerError
    })?;
    let feed_id = Uuid::parse_str(&row.feed_id).map_err(|e| {
        eprintln!("Failed to parse feed_id UUID: {}", e);
        Status::InternalServerError
    })?;

    Ok(Json(Feed {
        feed_id,
        name: row.name,
        url,
        user_id,
        added_time: row.added_time,
        last_checked_time: row.last_checked_time,
        categorization,
    }))
}