use std::fmt::Write;

use xshell::{cmd, cp, pushd, read_dir, write_file};

use crate::{codegen, date_iso, flags, is_release_tag, project_root, Mode, Result};

impl flags::Release {
    pub(crate) fn run(self) -> Result<()> {
        if !self.dry_run {
            cmd!("git switch release").run()?;
            cmd!("git fetch upstream --tags --force").run()?;
            cmd!("git reset --hard tags/nightly").run()?;
            cmd!("git push").run()?;
        }
        codegen::generate_assists_docs(Mode::Overwrite)?;
        codegen::generate_feature_docs(Mode::Overwrite)?;

        let website_root = project_root().join("../rust-analyzer.github.io");
        let changelog_dir = website_root.join("./thisweek/_posts");

        let today = date_iso()?;
        let commit = cmd!("git rev-parse HEAD").read()?;
        let changelog_n = read_dir(changelog_dir.as_path())?.len();

        for &adoc in [
            "manual.adoc",
            "generated_assists.adoc",
            "generated_config.adoc",
            "generated_diagnostic.adoc",
            "generated_features.adoc",
        ]
        .iter()
        {
            let src = project_root().join("./docs/user/").join(adoc);
            let dst = website_root.join(adoc);
            cp(src, dst)?;
        }

        let tags = cmd!("git tag --list").read()?;
        let prev_tag = tags.lines().filter(|line| is_release_tag(line)).last().unwrap();

        let git_log = cmd!("git log {prev_tag}..HEAD --merges --reverse").read()?;
        let mut git_log_summary = String::new();
        for line in git_log.lines() {
            let line = line.trim_start();
            if let Some(p) = line.find(':') {
                if let Ok(pr) = line[..p].parse::<u32>() {
                    writeln!(git_log_summary, "* pr:{}[]{}", pr, &line[p + 1..]).unwrap();
                }
            }
        }

        let contents = format!(
            "\
= Changelog #{}
:sectanchors:
:page-layout: post

Commit: commit:{}[] +
Release: release:{}[]

== Sponsors

**Become a sponsor:** On https://opencollective.com/rust-analyzer/[OpenCollective] or
https://github.com/sponsors/rust-analyzer[GitHub Sponsors].

== New Features

{}

== Fixes

== Internal Improvements
",
            changelog_n, commit, today, git_log_summary
        );

        let path = changelog_dir.join(format!("{}-changelog-{}.adoc", today, changelog_n));
        write_file(&path, &contents)?;

        Ok(())
    }
}

impl flags::Promote {
    pub(crate) fn run(self) -> Result<()> {
        let _dir = pushd("../rust-rust-analyzer")?;
        cmd!("git switch master").run()?;
        cmd!("git fetch upstream").run()?;
        cmd!("git reset --hard upstream/master").run()?;
        cmd!("git submodule update --recursive").run()?;

        let branch = format!("rust-analyzer-{}", date_iso()?);
        cmd!("git switch -c {branch}").run()?;
        {
            let _dir = pushd("src/tools/rust-analyzer")?;
            cmd!("git fetch origin").run()?;
            cmd!("git reset --hard origin/release").run()?;
        }
        cmd!("git add src/tools/rust-analyzer").run()?;
        cmd!("git commit -m':arrow_up: rust-analyzer'").run()?;
        if !self.dry_run {
            cmd!("git push -u").run()?;
            cmd!("xdg-open https://github.com/matklad/rust/pull/new/{branch}?body=r%3F%20%40ghost")
                .run()?;
        }
        Ok(())
    }
}