#!/bin/sh
# Ridgun installer (www-ridgun FR-DL-003), written by https://ridgun.com/install.sh for Ridgun 1.0.9.
#
#   curl -fsSL https://ridgun.com/install.sh | sh
#
# Downloads, into a temporary folder, what omni needs: the release for this system, the newest libs and the index.
# It checks the release against its SHA256SUMS before running anything from it, then hands over to `omni setup`,
# which checks every signature with the release key built into omni (ADR-0004) and installs ridgunc, stable and omni
# in ~/.local/bin and the standard libraries in ~/.local/lib/ridgun (it keeps its own copy in ~/.omni). Nothing is
# installed if a check fails. Nothing else on the system is touched.
set -eu

version='1.0.9'
base='https://ridgun.com'
files='x86_64-linux ridgun-1.0.9-x86_64-linux.tar.gz
arm64-linux ridgun-1.0.9-arm64-linux.tar.gz
x86_64-macos ridgun-1.0.9-x86_64-macos.tar.gz
arm64-macos ridgun-1.0.9-arm64-macos.tar.gz
x86_64-windows ridgun-1.0.9-x86_64-windows.tar.gz
arm64-windows ridgun-1.0.9-arm64-windows.tar.gz'

say() { printf 'ridgun: %s\n' "$*"; }
fail() { printf 'ridgun: %s\n' "$*" >&2; exit 1; }

[ -n "$version" ] || fail "no Ridgun release is published yet: see $base/download"

case "$(uname -s)" in
  Linux) os=linux ;;
  Darwin) os=macos ;;
  MINGW* | MSYS* | CYGWIN*) os=windows ;;
  *) os=$(uname -s | tr 'A-Z' 'a-z') ;;
esac
case "$(uname -m)" in
  x86_64 | amd64) arch=x86_64 ;;
  aarch64 | arm64) arch=arm64 ;;
  *) arch=$(uname -m) ;;
esac
target="$arch-$os"
# Git Bash, MSYS2 and Cygwin on Windows: the programs end in .exe (PowerShell has install.ps1).
exe=""
[ "$os" = windows ] && exe=".exe"
file=$(printf '%s\n' "$files" | awk -v t="$target" '$1 == t { print $2; exit }')
[ -n "$file" ] || fail "Ridgun $version has no download for $target yet: see $base/download"

if command -v curl >/dev/null 2>&1; then
  get() { curl -fsSL -o "$2" "$1"; }
elif command -v wget >/dev/null 2>&1; then
  get() { wget -q -O "$2" "$1"; }
else
  fail "needs curl or wget"
fi
# macOS has shasum, not always sha256sum.
if command -v sha256sum >/dev/null 2>&1; then
  sums_ok() { sha256sum -c --status; }
elif command -v shasum >/dev/null 2>&1; then
  sums_ok() { shasum -a 256 -c --status; }
else
  fail "needs sha256sum or shasum"
fi

# The temporary folder is laid out like $base/downloads, so omni reads it as its mirror.
tmp=$(mktemp -d)
trap 'rm -rf "$tmp"' EXIT
cd "$tmp"

# A release folder: one file with its SHA256SUMS and their signature.
get_release() {
  mkdir -p "$1"
  get "$base/downloads/$1/$2" "$1/$2" || fail "could not download $2"
  get "$base/downloads/$1/SHA256SUMS" "$1/SHA256SUMS" || fail "could not download the SHA256SUMS of $2"
  get "$base/downloads/$1/SHA256SUMS.minisig" "$1/SHA256SUMS.minisig" || fail "could not download the signature of $2"
}

say "downloading Ridgun $version for $target"
get "$base/downloads/index.tsv" index.tsv || fail "could not download the index of releases"
get_release "$version" "$file"
(cd "$version" && grep "  $file\$" SHA256SUMS | sums_ok) || fail "the checksum of $file does not match: nothing installed"

# The newest libs in the index (columns: product, version, target, path).
libs=$(awk -F '\t' '$1 == "libs" { split($2, v, "."); k = v[1] * 1000000 + v[2] * 1000 + v[3]; if (k >= best) { best = k; p = $4 } } END { print p }' index.tsv)
[ -n "$libs" ] || fail "the index has no standard libraries (libs)"
say "downloading the standard libraries ($(basename "$libs" .tar.gz))"
get_release "$(dirname "$libs")" "$(basename "$libs")"

tar -xzf "$version/$file"
[ -x "ridgun-$version/bin/omni$exe" ] || fail "this release has no omni: see $base/download"
# omni.exe is a Windows program: it reads the folder as a Windows path.
mirror="$tmp"
[ "$os" = windows ] && command -v cygpath >/dev/null 2>&1 && mirror=$(cygpath -w "$tmp")
OMNI_DOWNLOADS_MIRROR="$mirror" "./ridgun-$version/bin/omni$exe" setup "$target" || fail "omni setup failed: nothing more was installed"

dest="$HOME/.local/bin"
case ":$PATH:" in
  *":$dest:"*) "$dest/ridgunc$exe" --version ;;
  *)
    case "${SHELL:-}" in
      *zsh) profile="~/.zprofile" ;;
      *) [ "$os" = windows ] && profile="~/.bashrc" || profile="~/.profile" ;;
    esac
    say "add $dest to your PATH: echo 'export PATH=\"$dest:\$PATH\"' >> $profile" ;;
esac
say "add a library to a project with: omni install <library>; install a package's programs with: omni install -g <package> (see $base/packages)"