use phoebe::{
    attachments::attachment_to_url,
    mid_chat::{ChatAttachment, ChatMessage, ChatMessageEdit, ChatMessageReference, ChatReference},
    prelude::*,
};

use serenity::{http::AttachmentType, model::prelude::*, prelude::*};

use crate::{chat_conv, discord_reference, DiscordService};

async fn get_or_create_webhook_for_channel(
    discord: &mut DiscordService,
    channel: &ChannelId,
) -> Option<Webhook> {
    if let Ok(webhooks) = channel.webhooks(&discord.ctx).await {
        for webhook in webhooks {
            if matches!(webhook.name.as_deref(), Some("Phoebe")) {
                return Some(webhook);
            }
        }
    }

    if let Ok(webhook) = channel.create_webhook(&discord.ctx, "Phoebe").await {
        return Some(webhook);
    }

    None
}

async fn create_webhook_reply_embeds(
    discord_ctx: &Context,
    channel_id: ChannelId,
    message_id: MessageId,
) -> Vec<serde_json::Value> {
    if let Ok(replied_message) = channel_id.message(discord_ctx, message_id).await {
        let replied_author_name = format!(
            "{} ↩️",
            replied_message
                .author_nick(discord_ctx)
                .await
                .as_ref()
                .unwrap_or(&replied_message.author.name)
        );

        let reply_description = format!(
            "**[Reply to:]({})**\n{}",
            replied_message.id.link(
                channel_id,
                discord_ctx
                    .cache
                    .guild_channel(channel_id)
                    .await
                    .map(|gc| gc.guild_id)
            ),
            &replied_message.content
        );

        return vec![Embed::fake(|e| {
            e.author(|a| {
                a.icon_url(
                    &replied_message
                        .author
                        .static_avatar_url()
                        .unwrap_or_else(|| replied_message.author.default_avatar_url()),
                )
                .name(replied_author_name)
            })
            .description(reply_description)
        })];
    }

    vec![]
}

async fn create_discord_attachments(source: &'_ ChatMessage) -> Vec<AttachmentType<'_>> {
    source
        .attachments
        .iter()
        .map(|a| match a {
            ChatAttachment::Online {
                url,
                media_type: Some(media_type),
            } => {
                if media_type.starts_with("image/") {
                    AttachmentType::Image(url)
                } else {
                    todo!("Handle non-image online attachment")
                }
            }
            ChatAttachment::Online { .. } => {
                todo!("Handle online attachment with no media_type")
            }
            ChatAttachment::InMemory {
                file_name, data, ..
            } => AttachmentType::Bytes {
                filename: file_name.clone(),
                data: data.into(),
            },
        })
        .collect()
}

pub async fn send_discord_message(
    discord: &mut DiscordService,
    source: &ChatMessage,
    destination_channel: ChatReference,
) -> Result<ChatMessageReference> {
    let channel_id = destination_channel.id.parse::<ChannelId>()?;

    let discord_reply = if let Some(reply) = &source.replying {
        if let Some(reply_ref) = discord
            .lookup_message(reply, |r| future::ready(r.channel == destination_channel))
            .await
        {
            assert_eq!(reply_ref.channel.service, "discord");
            let channel_id: ChannelId = reply_ref.channel.id.parse().unwrap();
            let message_id: MessageId = reply_ref.message_id.parse::<u64>().unwrap().into();
            Some((channel_id, message_id))
        } else {
            None
        }
    } else {
        None
    };

    let files = create_discord_attachments(source).await;

    if let Some(webhook) = get_or_create_webhook_for_channel(&mut *discord, &channel_id).await {
        let reply_embeds = if let Some((channel, message)) = discord_reply {
            create_webhook_reply_embeds(&discord.ctx, channel, message).await
        } else {
            vec![]
        };

        let avatar_url = attachment_to_url(&source.author.avatar).await;

        if let Some(sent_message) = webhook
            .execute(&discord.ctx, true, |w| {
                w.content(chat_conv::format(&source.content))
                    .username(format!(
                        "{} ({})",
                        &source.author.display_name, &source.author.reference.service
                    ))
                    .avatar_url(&avatar_url)
                    .embeds(reply_embeds)
                    .add_files(files.clone())
            })
            .await?
        {
            return Ok(ChatMessageReference::new(
                discord_reference(sent_message.channel_id),
                sent_message.id,
            ));
        }
    }

    let content = format!(
        "{} ({}): {}",
        source.author.display_name,
        source.author.reference.service,
        chat_conv::format(&source.content)
    );

    let sent_message = channel_id
        .send_message(&discord.ctx, move |m| {
            let m = m.content(content);
            let m = m.add_files(files);
            if let Some(reply) = discord_reply {
                m.reference_message(reply)
            } else {
                m
            }
        })
        .await?;

    Ok(ChatMessageReference::new(
        discord_reference(sent_message.channel_id),
        sent_message.id,
    ))
}

pub async fn delete_discord_message(
    discord: &mut DiscordService,
    message: &ChatMessageReference,
) -> Result<()> {
    let channel_id = message.channel.id.parse::<ChannelId>()?;
    let message_id: MessageId = message.message_id.parse::<u64>()?.into();

    if let Some(webhook) = get_or_create_webhook_for_channel(&mut *discord, &channel_id).await {
        if webhook
            .delete_message(&discord.ctx, message_id)
            .await
            .is_ok()
        {
            return Ok(());
        }
    }

    channel_id.delete_message(&discord.ctx, message_id).await?;
    Ok(())
}

pub async fn edit_discord_message(
    discord: &mut DiscordService,
    prev_origin: &ChatMessageReference,
    edit: &ChatMessageEdit,
) -> Result<()> {
    let channel_id = prev_origin.channel.id.parse::<ChannelId>()?;
    let message_id: MessageId = prev_origin.message_id.parse::<u64>()?.into();

    if let Some(webhook) = get_or_create_webhook_for_channel(&mut *discord, &channel_id).await {
        if webhook
            .edit_message(&discord.ctx, message_id, |w| {
                w.content(chat_conv::format(&edit.new_content))
            })
            .await
            .is_ok()
        {
            return Ok(());
        }
    }

    let content = format!(
        "{} ({}): {}",
        edit.author.display_name,
        edit.author.reference.service,
        chat_conv::format(&edit.new_content)
    );

    channel_id
        .edit_message(&discord.ctx, message_id, |m| m.content(content))
        .await?;

    Ok(())
}