//! Repository overview, tree, file, raw and blame pages.

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

use crate::auth::Viewer;

use crate::render::{self, highlight};

use crate::repos::view::{self, EntryKind, FileBody};

use crate::Shared;

use askama::Template;

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

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

use serde::Deserialize;

#[derive(Template)]

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

pub struct OverviewPage {

    shell: Shell,

    repo: RepoShell,

    o: view::Overview,

    readme_html: Option<String>,

}

pub async fn overview(

    State(app): State<Shared>,

    viewer: Viewer,

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

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

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

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

    let default = row.default_bookmark.clone();

    let o =

        app.repos.read(&repo, move |r, cache| view::overview(r, cache, &default)).await.map_err(|e| Error::from_repo(shell.clone(), e))?;

    let rs = RepoShell::new(&app, &row, "code").with_role(role);

    let readme_html = o.readme_html(&rs, &o.tree.target.label);

    Ok(Page(OverviewPage { shell, repo: rs, o, readme_html }))

}

impl view::Overview {

    fn readme_html(&self, rs: &RepoShell, r: &str) -> Option<String> {

        self.tree.readme.as_ref().map(|md| {

            let dir = md.path.rsplit_once('/').map(|(d, _)| format!("{d}/")).unwrap_or_default();

            render::markdown::render(&md.text, &format!("{}/file/{r}/{dir}", rs.url), &format!("{}/file/{r}/{dir}", rs.url))

        })

    }

}

#[derive(Template)]

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

pub struct TreePage {

    shell: Shell,

    repo: RepoShell,

    t: view::Tree,

    readme_html: Option<String>,

}

pub async fn tree_root(

    State(app): State<Shared>,

    viewer: Viewer,

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

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

    tree(State(app), viewer, Path((owner, name, r, String::new()))).await

}

pub async fn tree(

    State(app): State<Shared>,

    viewer: Viewer,

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

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

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

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

    let (spec, dir) = (r.clone(), path.clone());

    let t = app

        .repos

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

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

            view::tree(repo, cache, target, &dir)

        })

        .await

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

    let rs = RepoShell::new(&app, &row, "code").with_role(role);

    let readme_html = t.readme.as_ref().map(|md| {

        let dir = md.path.rsplit_once('/').map(|(d, _)| format!("{d}/")).unwrap_or_default();

        render::markdown::render(&md.text, &format!("{}/file/{r}/{dir}", rs.url), &format!("{}/file/{r}/{dir}", rs.url))

    });

    Ok(Page(TreePage { shell, repo: rs, t, readme_html }))

}

#[derive(Deserialize)]

pub struct FileQuery {

    plain: Option<String>,

    blame: Option<String>,

    /// `source` shows a Markdown file's text instead of rendering it.

    view: Option<String>,

}

#[derive(Template)]

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

pub struct FilePage {

    shell: Shell,

    repo: RepoShell,

    f: view::FileView,

    /// Highlighted lines when text.

    lines: Vec<String>,

    language: Option<&'static str>,

    markdown_html: Option<String>,

    is_image: bool,

    is_markdown: bool,

    blame: Option<Vec<BlameRow>>,

}

/// A blame gutter entry: shown only on the first line of a run.

pub struct BlameRow {

    pub first: bool,

    pub hash: String,

    pub short: String,

    pub author: String,

    pub when_ms: u64,

    pub run: usize,

}

pub async fn file(

    State(app): State<Shared>,

    viewer: Viewer,

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

    Query(q): Query<FileQuery>,

) -> Result<Response, Error> {

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

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

    let limit = app.config.limits.render_limit.0;

    let want_blame = q.blame.is_some();

    let (spec, p) = (r.clone(), path.clone());

    let (f, blame) = app

        .repos

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

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

            if want_blame {

                let b = view::blame(repo, cache, target, &p, limit)?;

                Ok((b.file, Some(b.lines)))

            } else {

                Ok((view::file(repo, cache, target, &p, limit)?, None))

            }

        })

        .await

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

    if q.plain.is_some() {

        return Ok(super::raw(f.bytes, &f.name, true));

    }

    let rs = RepoShell::new(&app, &row, "code").with_role(role);

    let is_image = super::mime_of(&f.name).starts_with("image/");

    let is_markdown = f.name.to_lowercase().ends_with(".md") || f.name.to_lowercase() == "readme";

    let want_source = q.view.as_deref() == Some("source") || blame.is_some();

    let (lines, language, markdown_html) = match &f.body {

        FileBody::Text(text) if !is_image => {

            if is_markdown && !want_source {

                let dir = f.path.rsplit_once('/').map(|(d, _)| format!("{d}/")).unwrap_or_default();

                let base = format!("{}/file/{r}/{dir}", rs.url);

                (vec![], highlight::language(&f.path), Some(render::markdown::render(text, &base, &base)))

            } else {

                (highlight::lines(&f.path, text), highlight::language(&f.path), None)

            }

        }

        _ => (vec![], None, None),

    };

    let blame = blame.map(|lines| {

        let mut rows: Vec<BlameRow> = Vec::with_capacity(lines.len());

        let mut i = 0;

        while i < lines.len() {

            let mut run = 1;

            while i + run < lines.len() && lines[i + run].hash == lines[i].hash {

                run += 1;

            }

            for k in 0..run {

                let l = &lines[i + k];

                rows.push(BlameRow {

                    first: k == 0,

                    hash: l.hash.to_hex(),

                    short: l.hash.short(8),

                    author: l.author.clone(),

                    when_ms: l.when_ms,

                    run,

                });

            }

            i += run;

        }

        rows

    });

    Ok(Page(FilePage { shell, repo: rs, f, lines, language, markdown_html, is_image, is_markdown, blame }).into_response())

}

#[derive(Deserialize)]

pub struct LastQuery {

    /// Comma-separated paths.

    paths: String,

}

/// `GET /{owner}/{name}/last/{ref}?paths=a,b` → JSON of last change per

/// path, fetched by the tree page after it paints (hub spec §6.5).

pub async fn last_changes(

    State(app): State<Shared>,

    viewer: Viewer,

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

    Query(q): Query<LastQuery>,

) -> Result<Response, Error> {

    let shell = Shell::new(&app, "", &viewer);

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

    let paths: Vec<String> = q.paths.split(',').filter(|p| !p.is_empty()).take(500).map(String::from).collect();

    let spec = r.clone();

    let found = app

        .repos

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

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

            view::last_changes(repo, cache, &target.heads, &paths)

        })

        .await

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

    let now = crate::db::now_ms() as u64;

    let body: Vec<serde_json::Value> = found

        .into_iter()

        .map(|(p, c)| {

            serde_json::json!({ "path": p, "hash": c.hash, "short": c.short, "title": c.title, "ago": render::time::ago(c.when_ms, now), "when": render::time::absolute(c.when_ms) })

        })

        .collect();

    Ok(axum::Json(body).into_response())

}

impl EntryKind {

    pub fn glyph(&self) -> &'static str {

        match self {

            EntryKind::Dir => "▸",

            EntryKind::File => "·",

            EntryKind::Symlink => "↪",

            EntryKind::Subrepo => "◫",

        }

    }

}