use async_graphql::{
    connection::{Connection},
    Context, EmptySubscription, Enum, Error, FieldResult, Object, Schema, SimpleObject, Union,
};
use log::info;
use notmuch::Notmuch;
use sqlx::postgres::PgPool;

use crate::{newsreader, nm};

/// # Number of seconds since the Epoch
pub type UnixTime = isize;

/// # Thread ID, sans "thread:"
pub type ThreadId = String;

#[derive(Debug, SimpleObject)]
pub struct ThreadSummary {
    pub thread: ThreadId,
    pub timestamp: UnixTime,
    /// user-friendly timestamp
    pub date_relative: String,
    /// number of matched messages
    pub matched: isize,
    /// total messages in thread
    pub total: isize,
    /// comma-separated names with | between matched and unmatched
    pub authors: String,
    pub subject: String,
    pub tags: Vec<String>,
}

#[derive(Debug, SimpleObject)]
pub struct Thread {
    pub thread_id: String,
    pub subject: String,
    pub messages: Vec<Message>,
}

#[derive(Debug, SimpleObject)]
pub struct Message {
    // Message-ID for message, prepend `id:<id>` to search in notmuch
    pub id: String,
    // First From header found in email
    pub from: Option<Email>,
    // All To headers found in email
    pub to: Vec<Email>,
    // All CC headers found in email
    pub cc: Vec<Email>,
    // First Subject header found in email
    pub subject: Option<String>,
    // Parsed Date header, if found and valid
    pub timestamp: Option<i64>,
    // Headers
    pub headers: Vec<Header>,
    // The body contents
    pub body: Body,
    // On disk location of message
    pub path: String,
    pub attachments: Vec<Attachment>,
    pub tags: Vec<String>,
}

// Content-Type: image/jpeg; name="PXL_20231125_204826860.jpg"
// Content-Disposition: attachment; filename="PXL_20231125_204826860.jpg"
// Content-Transfer-Encoding: base64
// Content-ID: <f_lponoluo1>
// X-Attachment-Id: f_lponoluo1
#[derive(Default, Debug, SimpleObject)]
pub struct Attachment {
    pub id: String,
    pub idx: String,
    pub filename: Option<String>,
    pub size: usize,
    pub content_type: Option<String>,
    pub content_id: Option<String>,
    pub disposition: DispositionType,
    pub bytes: Vec<u8>,
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Disposition {
    pub r#type: DispositionType,
    pub filename: Option<String>,
    pub size: Option<usize>,
}

#[derive(Debug, Enum, Copy, Clone, Eq, PartialEq)]
pub enum DispositionType {
    Inline,
    Attachment,
}

impl From<mailparse::DispositionType> for DispositionType {
    fn from(value: mailparse::DispositionType) -> Self {
        match value {
            mailparse::DispositionType::Inline => DispositionType::Inline,
            mailparse::DispositionType::Attachment => DispositionType::Attachment,
            dt => panic!("unhandled DispositionType {dt:?}"),
        }
    }
}

impl Default for DispositionType {
    fn default() -> Self {
        DispositionType::Attachment
    }
}

#[derive(Debug, SimpleObject)]
pub struct Header {
    pub key: String,
    pub value: String,
}

#[derive(Debug)]
pub struct UnhandledContentType {
    pub text: String,
    pub content_tree: String,
}

#[Object]
impl UnhandledContentType {
    async fn contents(&self) -> &str {
        &self.text
    }
    async fn content_tree(&self) -> &str {
        &self.content_tree
    }
}

#[derive(Debug)]
pub struct PlainText {
    pub text: String,
    pub content_tree: String,
}

#[Object]
impl PlainText {
    async fn contents(&self) -> &str {
        &self.text
    }
    async fn content_tree(&self) -> &str {
        &self.content_tree
    }
}

#[derive(Debug)]
pub struct Html {
    pub html: String,
    pub content_tree: String,
}

#[Object]
impl Html {
    async fn contents(&self) -> &str {
        &self.html
    }
    async fn content_tree(&self) -> &str {
        &self.content_tree
    }
    async fn headers(&self) -> Vec<Header> {
        Vec::new()
    }
}

#[derive(Debug, Union)]
pub enum Body {
    UnhandledContentType(UnhandledContentType),
    PlainText(PlainText),
    Html(Html),
}

impl Body {
    pub fn html(html: String) -> Body {
        Body::Html(Html {
            html,
            content_tree: "".to_string(),
        })
    }
    pub fn text(text: String) -> Body {
        Body::PlainText(PlainText {
            text,
            content_tree: "".to_string(),
        })
    }
}

#[derive(Debug, SimpleObject)]
pub struct Email {
    pub name: Option<String>,
    pub addr: Option<String>,
}

#[derive(SimpleObject)]
pub(crate) struct Tag {
    pub name: String,
    pub fg_color: String,
    pub bg_color: String,
    pub unread: usize,
}

pub struct QueryRoot;
#[Object]
impl QueryRoot {
    async fn count<'ctx>(&self, ctx: &Context<'ctx>, query: String) -> Result<usize, Error> {
        let nm = ctx.data_unchecked::<Notmuch>();
        let pool = ctx.data_unchecked::<PgPool>();

        // TODO: make this search both copra and merge results
        if newsreader::is_newsreader_search(&query) {
            Ok(newsreader::count(pool, &query).await?)
        } else {
            Ok(nm::count(nm, &query).await?)
        }
    }

    async fn search<'ctx>(
        &self,
        ctx: &Context<'ctx>,
        after: Option<String>,
        before: Option<String>,
        first: Option<i32>,
        last: Option<i32>,
        query: String,
    ) -> Result<Connection<usize, ThreadSummary>, Error> {
        info!("search({after:?} {before:?} {first:?} {last:?} {query:?})");
        let nm = ctx.data_unchecked::<Notmuch>();
        let pool = ctx.data_unchecked::<PgPool>();

        // TODO: make this search both copra and merge results
        if newsreader::is_newsreader_search(&query) {
            Ok(newsreader::search(pool, after, before, first, last, query).await?)
        } else {
            Ok(nm::search(nm, after, before, first, last, query).await?)
        }
    }

    async fn tags<'ctx>(&self, ctx: &Context<'ctx>) -> FieldResult<Vec<Tag>> {
        let nm = ctx.data_unchecked::<Notmuch>();
        let pool = ctx.data_unchecked::<PgPool>();
        let needs_unread = ctx.look_ahead().field("unread").exists();
        let mut tags = newsreader::tags(pool, needs_unread).await?;
        tags.append(&mut nm::tags(nm, needs_unread)?);
        Ok(tags)
    }
    async fn thread<'ctx>(&self, ctx: &Context<'ctx>, thread_id: String) -> Result<Thread, Error> {
        let nm = ctx.data_unchecked::<Notmuch>();
        let pool = ctx.data_unchecked::<PgPool>();
        let debug_content_tree = ctx
            .look_ahead()
            .field("messages")
            .field("body")
            .field("contentTree")
            .exists();
        // TODO: look at thread_id and conditionally load newsreader
        if newsreader::is_newsreader_thread(&thread_id) {
            Ok(newsreader::thread(pool, thread_id).await?)
        } else {
            Ok(nm::thread(nm, thread_id, debug_content_tree).await?)
        }
    }
}

pub struct Mutation;
#[Object]
impl Mutation {
    async fn set_read_status<'ctx>(
        &self,
        ctx: &Context<'ctx>,
        query: String,
        unread: bool,
    ) -> Result<bool, Error> {
        let nm = ctx.data_unchecked::<Notmuch>();
        info!("set_read_status({unread})");
        if unread {
            nm.tag_add("unread", &format!("{query}"))?;
        } else {
            nm.tag_remove("unread", &format!("{query}"))?;
        }
        Ok(true)
    }
    async fn tag_add<'ctx>(
        &self,
        ctx: &Context<'ctx>,
        query: String,
        tag: String,
    ) -> Result<bool, Error> {
        let nm = ctx.data_unchecked::<Notmuch>();
        info!("tag_add({tag}, {query})");
        nm.tag_add(&tag, &query)?;
        Ok(true)
    }
    async fn tag_remove<'ctx>(
        &self,
        ctx: &Context<'ctx>,
        query: String,
        tag: String,
    ) -> Result<bool, Error> {
        let nm = ctx.data_unchecked::<Notmuch>();
        info!("tag_remove({tag}, {query})");
        nm.tag_remove(&tag, &query)?;
        Ok(true)
    }
}

pub type GraphqlSchema = Schema<QueryRoot, Mutation, EmptySubscription>;