//! Releases (hub spec §9): notes and assets on a tag, generated notes from

//! the changes since the previous release, source archives of any state.

use super::settings::{csrf, require};

use super::{filters, lookup, lookup_role, Error, Page, RepoShell, Shell};

use crate::auth::{Access, Viewer};

use crate::db::{self, accounts, releases as rdb};

use crate::repos::archive::{self, Format};

use crate::repos::{view, RepoName};

use crate::Shared;

use askama::Template;

use axum::extract::{Form, Multipart, Path, Query, State};

use axum::http::header;

use axum::response::{IntoResponse, Redirect, Response};

use oxy_core::hash::ChangeHash;

use serde::Deserialize;

use std::collections::HashMap;

/// A release as the pages and the API show it.

pub struct ReleaseView {

    pub r: rdb::Release,

    pub notes_html: String,

    pub assets: Vec<rdb::Asset>,

    pub heads: Vec<String>,

    pub signer: Option<String>,

    pub latest: bool,

}

async fn views(app: &Shared, repo: &RepoName, row: &db::repos::RepoRow) -> Result<Vec<ReleaseView>, sqlx::Error> {

    let list = rdb::list(&app.db, row.id).await?;

    let latest = rdb::latest(&app.db, row.id).await?.map(|r| r.id);

    let tags: HashMap<String, (Vec<String>, Option<String>)> = app

        .repos

        .read(repo, |r, _| Ok(view::tags(r)?.into_iter().map(|t| (t.name, (t.heads, t.signer))).collect()))

        .await

        .unwrap_or_default();

    let mut out = Vec::new();

    for r in list {

        let assets = rdb::assets(&app.db, r.id).await?;

        let (heads, signer) = tags.get(&r.tag).cloned().unwrap_or_default();

        let notes_html = super::issues::markdown(app, row.id, &format!("/{}", row.slug()), &r.notes).await;

        out.push(ReleaseView { latest: Some(r.id) == latest, r, notes_html, assets, heads, signer });

    }

    Ok(out)

}

#[derive(Template)]

#[template(path = "releases.html")]

pub struct ReleasesPage {

    shell: Shell,

    repo: RepoShell,

    releases: Vec<ReleaseView>,

    unreleased: Vec<String>,

    one: bool,

}

pub async fn list(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name)): Path<(String, String)>,

) -> Result<Page<ReleasesPage>, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/releases"), &viewer);

    let (repo, row, role) = lookup(&app, &shell, &viewer, &owner, &name).await?;

    let releases = views(&app, &repo, &row).await.map_err(|e| Error::from_db(shell.clone(), e))?;

    let tags: Vec<String> =

        app.repos.read(&repo, |r, _| Ok(view::tags(r)?.into_iter().map(|t| t.name).collect())).await.unwrap_or_default();

    let unreleased = tags.into_iter().filter(|t| !releases.iter().any(|r| &r.r.tag == t)).collect();

    Ok(Page(ReleasesPage { shell, repo: RepoShell::new(&app, &row, "releases").with_role(role), releases, unreleased, one: false }))

}

pub async fn show(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name, tag)): Path<(String, String, String)>,

) -> Result<Page<ReleasesPage>, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/releases/tag/{tag}"), &viewer);

    let (repo, row, role) = lookup(&app, &shell, &viewer, &owner, &name).await?;

    let releases: Vec<ReleaseView> =

        views(&app, &repo, &row).await.map_err(|e| Error::from_db(shell.clone(), e))?.into_iter().filter(|r| r.r.tag == tag).collect();

    if releases.is_empty() {

        return Err(Error::not_found(shell));

    }

    Ok(Page(ReleasesPage { shell, repo: RepoShell::new(&app, &row, "releases").with_role(role), releases, unreleased: vec![], one: true }))

}

/// Notes drafted from the changes in `tag`'s state that the previous

/// release's state lacks: one line per change, newest first.

async fn generated_notes(app: &Shared, repo: &RepoName, repo_id: i64, tag: &str) -> String {

    let previous = rdb::list(&app.db, repo_id).await.unwrap_or_default().into_iter().find(|r| r.tag != tag).map(|r| r.tag);

    let tag = tag.to_string();

    app.repos

        .read(repo, move |r, cache| {

            let Some(heads) = r.tag_heads(&tag)? else { return Ok(String::new()) };

            let now = cache.load(r, &heads)?;

            let before: Vec<ChangeHash> = match &previous {

                Some(p) => r.tag_heads(p)?.unwrap_or_default(),

                None => vec![],

            };

            let then = cache.load(r, &before)?;

            let mut added: Vec<_> = now

                .state

                .changes()

                .filter(|(h, _)| !then.state.contains(h))

                .map(|(h, m)| (m.hlc, *h, m.message.clone(), m.author))

                .collect();

            added.sort_by_key(|a| std::cmp::Reverse(a.0));

            let mut out = match &previous {

                Some(p) => format!("Changes since {p}:\n\n"),

                None => "Changes:\n\n".to_string(),

            };

            for (_, h, message, author) in added {

                let who = view::author(r, &author, &message).name;

                out.push_str(&format!("- {} ({}, {})\n", message.lines().next().unwrap_or(""), &h.to_hex()[..12], who));

            }

            Ok(out)

        })

        .await

        .unwrap_or_default()

}

#[derive(Template)]

#[template(path = "release_new.html")]

pub struct NewReleasePage {

    shell: Shell,

    repo: RepoShell,

    tags: Vec<String>,

    tag: String,

    notes: String,

    error: Option<String>,

}

#[derive(Deserialize)]

pub struct NewQuery {

    tag: Option<String>,

}

pub async fn new_form(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name)): Path<(String, String)>,

    Query(q): Query<NewQuery>,

) -> Result<Page<NewReleasePage>, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/releases/new"), &viewer);

    require(&viewer, &shell)?;

    let (repo, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Write).await?;

    let tags: Vec<String> = app

        .repos

        .read(&repo, |r, _| Ok(view::tags(r)?.into_iter().map(|t| t.name).collect()))

        .await

        .map_err(|e| Error::from_repo(shell.clone(), e))?;

    let tag = q.tag.filter(|t| tags.contains(t)).or_else(|| tags.first().cloned()).unwrap_or_default();

    let notes = if tag.is_empty() { String::new() } else { generated_notes(&app, &repo, row.id, &tag).await };

    Ok(Page(NewReleasePage { shell, repo: RepoShell::new(&app, &row, "releases").with_role(role), tags, tag, notes, error: None }))

}

#[derive(Deserialize)]

pub struct NewForm {

    #[serde(rename = "_csrf")]

    csrf_token: String,

    tag: String,

    title: String,

    #[serde(default)]

    notes: String,

    #[serde(default)]

    prerelease: Option<String>,

}

/// Create a release for an existing tag; shared by the form and the API.

#[allow(clippy::too_many_arguments)]

pub async fn create_release(

    app: &Shared,

    repo: &RepoName,

    row: &db::repos::RepoRow,

    me: &accounts::Account,

    tag: &str,

    title: &str,

    notes: Option<String>,

    prerelease: bool,

) -> Result<rdb::Release, String> {

    let exists = app

        .repos

        .read(repo, {

            let t = tag.to_string();

            move |r, _| Ok(r.tag_heads(&t)?.is_some())

        })

        .await

        .map_err(|e| e.to_string())?;

    if !exists {

        return Err(format!("there is no tag {tag}; create it with oxy tag create and push it"));

    }

    if rdb::get(&app.db, row.id, tag).await.map_err(|e| e.to_string())?.is_some() {

        return Err(format!("{tag} already has a release"));

    }

    let notes = match notes {

        Some(n) => n,

        None => generated_notes(app, repo, row.id, tag).await,

    };

    let title = if title.trim().is_empty() { tag.to_string() } else { title.trim().to_string() };

    let r = rdb::create(&app.db, row.id, tag, &title, notes.trim(), prerelease, Some((me.id, &me.username)))

        .await

        .map_err(|e| e.to_string())?;

    accounts::audit(&app.db, Some(me), "release.published", &format!("{}@{tag}", row.slug()), "").await.ok();

    crate::hooks::emit(

        app,

        row,

        "release.published",

        &me.username,

        serde_json::json!({ "tag": tag, "title": title, "prerelease": prerelease }),

    )

    .await;

    crate::notify::deliver(

        app,

        crate::notify::Event {

            kind: "release",

            title: format!("{} released {title}", row.slug()),

            url: format!("/{}/releases/tag/{tag}", row.slug()),

            actor: me,

            repo_id: row.id,

            thread: None,

            mention_text: "",

            direct: vec![],

        },

    )

    .await;

    Ok(r)

}

pub async fn create(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name)): Path<(String, String)>,

    Form(f): Form<NewForm>,

) -> Result<Response, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/releases/new"), &viewer);

    let me = require(&viewer, &shell)?;

    csrf(&viewer, &f.csrf_token, &shell)?;

    let (repo, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Write).await?;

    match create_release(&app, &repo, &row, &me.account, &f.tag, &f.title, Some(f.notes.clone()), f.prerelease.is_some()).await {

        Ok(r) => Ok(Redirect::to(&format!("/{owner}/{name}/releases/tag/{}", r.tag)).into_response()),

        Err(msg) => {

            let tags = app.repos.read(&repo, |r, _| Ok(view::tags(r)?.into_iter().map(|t| t.name).collect())).await.unwrap_or_default();

            Ok(Page(NewReleasePage {

                shell,

                repo: RepoShell::new(&app, &row, "releases").with_role(role),

                tags,

                tag: f.tag,

                notes: f.notes,

                error: Some(msg),

            })

            .into_response())

        }

    }

}

#[derive(Deserialize)]

pub struct EditForm {

    #[serde(rename = "_csrf")]

    csrf_token: String,

    #[serde(default)]

    title: String,

    #[serde(default)]

    notes: String,

    #[serde(default)]

    prerelease: Option<String>,

    #[serde(default)]

    action: String,

    #[serde(default)]

    asset: Option<i64>,

}

pub async fn edit(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name, id)): Path<(String, String, i64)>,

    Form(f): Form<EditForm>,

) -> Result<Response, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/releases"), &viewer);

    let me = require(&viewer, &shell)?;

    csrf(&viewer, &f.csrf_token, &shell)?;

    let (_, row, _) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Write).await?;

    let e = |e| Error::from_db(shell.clone(), e);

    let Some(r) = rdb::list(&app.db, row.id).await.map_err(e)?.into_iter().find(|r| r.id == id) else {

        return Err(Error::not_found(shell));

    };

    match f.action.as_str() {

        "delete" => {

            let assets = rdb::assets(&app.db, r.id).await.map_err(e)?;

            rdb::delete(&app.db, r.id).await.map_err(e)?;

            for a in assets {

                remove_blob_if_unused(&app, &a.hash).await;

            }

            accounts::audit(&app.db, Some(&me.account), "release.deleted", &format!("{owner}/{name}@{}", r.tag), "").await.ok();

            return Ok(Redirect::to(&format!("/{owner}/{name}/releases")).into_response());

        }

        "delete_asset" => {

            if let Some(a) = rdb::assets(&app.db, r.id).await.map_err(e)?.into_iter().find(|a| Some(a.id) == f.asset) {

                rdb::delete_asset(&app.db, a.id).await.map_err(e)?;

                remove_blob_if_unused(&app, &a.hash).await;

            }

        }

        _ => rdb::edit(

            &app.db,

            r.id,

            if f.title.trim().is_empty() { &r.tag } else { f.title.trim() },

            f.notes.trim(),

            f.prerelease.is_some(),

        )

        .await

        .map_err(e)?,

    }

    Ok(Redirect::to(&format!("/{owner}/{name}/releases/tag/{}", r.tag)).into_response())

}

fn blob_path(app: &Shared, hash: &str) -> std::path::PathBuf {

    app.config.data.join("assets").join(&hash[..2]).join(hash)

}

async fn remove_blob_if_unused(app: &Shared, hash: &str) {

    if !rdb::hash_in_use(&app.db, hash).await.unwrap_or(true) {

        tokio::fs::remove_file(blob_path(app, hash)).await.ok();

    }

}

/// Store an uploaded asset by content and attach it to a release.

pub async fn store_asset(app: &Shared, release_id: i64, name: &str, content_type: &str, bytes: &[u8]) -> Result<rdb::Asset, String> {

    let name = name.rsplit(['/', '\\']).next().unwrap_or(name).trim();

    if name.is_empty() || name.starts_with('.') || name.len() > 200 {

        return Err("give the asset a file name".into());

    }

    if bytes.len() as u64 > app.config.limits.asset_limit.0 {

        return Err("the asset is larger than this hub allows".into());

    }

    let hash = hex::encode(blake3::hash(bytes).as_bytes());

    let path = blob_path(app, &hash);

    if !path.exists() {

        tokio::fs::create_dir_all(path.parent().unwrap()).await.map_err(|e| e.to_string())?;

        let tmp = path.with_extension("partial");

        tokio::fs::write(&tmp, bytes).await.map_err(|e| e.to_string())?;

        tokio::fs::rename(&tmp, &path).await.map_err(|e| e.to_string())?;

    }

    let ct = if content_type.is_empty() { "application/octet-stream" } else { content_type };

    rdb::add_asset(&app.db, release_id, name, bytes.len() as i64, &hash, ct).await.map_err(|e| e.to_string())

}

pub async fn upload(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name, id)): Path<(String, String, i64)>,

    mut multipart: Multipart,

) -> Result<Response, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/releases"), &viewer);

    require(&viewer, &shell)?;

    let (_, row, _) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Write).await?;

    let Some(r) = rdb::list(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?.into_iter().find(|r| r.id == id) else {

        return Err(Error::not_found(shell));

    };

    let mut token = String::new();

    let mut files: Vec<(String, String, Vec<u8>)> = vec![];

    while let Ok(Some(field)) = multipart.next_field().await {

        match field.name() {

            Some("_csrf") => token = field.text().await.unwrap_or_default(),

            Some("asset") => {

                let fname = field.file_name().unwrap_or("").to_string();

                let ct = field.content_type().unwrap_or("").to_string();

                let bytes = field.bytes().await.map_err(|e| Error::bad(shell.clone(), e.to_string()))?;

                if !fname.is_empty() {

                    files.push((fname, ct, bytes.to_vec()));

                }

            }

            _ => {}

        }

    }

    csrf(&viewer, &token, &shell)?;

    for (fname, ct, bytes) in files {

        store_asset(&app, r.id, &fname, &ct, &bytes).await.map_err(|m| Error::bad(shell.clone(), m))?;

    }

    Ok(Redirect::to(&format!("/{owner}/{name}/releases/tag/{}", r.tag)).into_response())

}

pub async fn download(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name, id, file)): Path<(String, String, i64, String)>,

) -> Result<Response, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/releases"), &viewer);

    let (_, row, _) = lookup(&app, &shell, &viewer, &owner, &name).await?;

    let e = |e| Error::from_db(shell.clone(), e);

    let asset: Option<rdb::Asset> =

        sqlx::query_as("SELECT a.* FROM release_assets a JOIN releases r ON r.id = a.release_id WHERE a.id = ? AND r.repo_id = ?")

            .bind(id)

            .bind(row.id)

            .fetch_optional(&app.db)

            .await

            .map_err(e)?;

    let Some(a) = asset.filter(|a| a.name == file) else { return Err(Error::not_found(shell)) };

    let bytes = tokio::fs::read(blob_path(&app, &a.hash)).await.map_err(|_| Error::not_found(shell.clone()))?;

    rdb::count_download(&app.db, a.id).await.ok();

    Ok((

        [

            (header::CONTENT_TYPE, a.content_type.clone()),

            (header::CONTENT_DISPOSITION, format!("attachment; filename=\"{}\"", a.name.replace('"', ""))),

            (header::X_CONTENT_TYPE_OPTIONS, "nosniff".to_string()),

            (header::CACHE_CONTROL, "public, max-age=31536000, immutable".to_string()),

        ],

        bytes,

    )

        .into_response())

}

#[derive(Deserialize)]

pub struct ArchiveQuery {

    #[serde(rename = "ref")]

    r: String,

    format: String,

}

/// `GET /{owner}/{name}/archive?ref=v1.0&format=tar.zst`: built once per

/// state and served from the cache after.

pub async fn source_archive(

    State(app): State<Shared>,

    viewer: Viewer,

    Path((owner, name)): Path<(String, String)>,

    Query(q): Query<ArchiveQuery>,

) -> Result<Response, Error> {

    let shell = Shell::new(&app, &format!("/{owner}/{name}/archive"), &viewer);

    let (repo, _, _) = lookup(&app, &shell, &viewer, &owner, &name).await?;

    let format = Format::parse(&q.format).ok_or_else(|| Error::bad(shell.clone(), "format is tar.zst or zip"))?;

    let label: String = q.r.chars().map(|c| if c.is_ascii_alphanumeric() || matches!(c, '.' | '-' | '_') { c } else { '-' }).collect();

    let prefix = format!("{name}-{}", label.trim_matches('-'));

    let data = app.config.data.clone();

    let spec = q.r.clone();

    let p = prefix.clone();

    let path = app

        .repos

        .read(&repo, move |r, cache| {

            let target = view::resolve(r, cache, &spec)?;