#!/usr/bin/env bash

set -euo pipefail

ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
TEMP_DIR=$(mktemp -d)
trap 'rm -rf "$TEMP_DIR"' EXIT

fail() {
    echo "FAIL: $*" >&2
    exit 1
}

assert_download_failure_is_reported() {
    local home="$TEMP_DIR/home-${1%.sh}"
    mkdir -p "$home"

    if HOME="$home" PATH="$TEMP_DIR/bin:/usr/bin:/bin" /bin/bash "$ROOT/$1" >"$home/output" 2>&1; then
        fail "$1 returned success after curl failed"
    fi
}

mkdir -p "$TEMP_DIR/bin"
ln -s /usr/bin/false "$TEMP_DIR/bin/curl"
ln -s /usr/bin/true "$TEMP_DIR/bin/unzip"

for script in install_fnm.sh install_nvm.sh install_pyenv.sh install_merlin_worker.sh; do
    assert_download_failure_is_reported "$script"
done

patch_home="$TEMP_DIR/patch-home"
mkdir -p "$patch_home/.config/zshrc"
cp "$ROOT/README.md" "$patch_home/.config/zshrc/missing.zsh"
if HOME="$patch_home" PATH="$TEMP_DIR/bin:/usr/bin:/bin" /bin/bash "$ROOT/patch.sh" missing >/dev/null 2>&1; then
    fail "patch.sh returned success after curl failed"
fi
cmp -s "$ROOT/README.md" "$patch_home/.config/zshrc/missing.zsh" ||
    fail "patch.sh replaced an existing config after curl failed"

if HOME="$patch_home" PATH="$TEMP_DIR/bin:/usr/bin:/bin" /bin/bash "$ROOT/patch.sh" ../invalid >/dev/null 2>&1; then
    fail "patch.sh accepted an unsafe config name"
fi

main_bin="$TEMP_DIR/main-bin"
main_home="$TEMP_DIR/main-home"
mkdir -p "$main_bin" "$main_home"
for command_name in zsh git curl tar fc-cache eza zoxide autoconf; do
    ln -s /usr/bin/true "$main_bin/$command_name"
done
ln -s /usr/bin/false "$main_bin/wget"
cp "$ROOT/README.md" "$main_home/.zshrc"
if HOME="$main_home" PATH="$main_bin:/usr/bin:/bin" /bin/bash "$ROOT/install.sh" --non-interactive >/dev/null 2>&1; then
    fail "install.sh returned success after the zshrc download failed"
fi
cmp -s "$ROOT/README.md" "$main_home/.zshrc" ||
    fail "install.sh replaced .zshrc after its download failed"

fnm_home="$TEMP_DIR/fnm-home"
mkdir -p "$fnm_home/.local/share/fnm"
ln -s /usr/bin/true "$fnm_home/.local/share/fnm/fnm"
HOME="$fnm_home" PATH=/usr/bin:/bin zsh -c 'source "$1"; command -v fnm >/dev/null' zsh "$ROOT/zshrc/fnm.zsh" ||
    fail "fnm is not restored to PATH in a new Zsh session"

for script in "$ROOT"/*.sh; do
    bash -n "$script"
done

for config in "$ROOT/.zshrc" "$ROOT"/zshrc/*.zsh; do
    zsh -n "$config"
done

grep -q 'NVM_VERSION="v0.40.4"' "$ROOT/install_nvm.sh" || fail "nvm version is stale"
grep -q 'apt-get install -y unzip' "$ROOT/install_fnm.sh" || fail "Ubuntu unzip installation is missing"
grep -q 'tail -1 || true' "$ROOT/install_merlin_worker.sh" || fail "a missing PYTHONPATH remains fatal"
grep -Fq 'mktemp "$HOME/.zshrc.download.' "$ROOT/install.sh" || fail ".zshrc is not downloaded on its target filesystem"
grep -Fq 'mktemp "$HOME/.config/.easyzsh-' "$ROOT/patch.sh" || fail "patch downloads can be sourced while incomplete"
grep -Fq '"$ZSH_CONFIGS_DIR"/*(DN)' "$ROOT/.zshrc" || fail "existing extensionless Zsh configs are ignored"
grep -Fq 'cp -Pp "$HOME/.zshrc"' "$ROOT/install.sh" || fail ".zshrc symlinks are not preserved in backups"
grep -Fq '[ -L "$HOME/.zshrc" ]' "$ROOT/install.sh" || fail "broken .zshrc symlinks are not backed up"
[[ ! -e "$ROOT/install/fnm.sh" ]] || fail "vendored fnm installer still exists"
if grep -Eq '^[[:space:]]*export MLX_USER_TOKEN=' "$ROOT"/zshrc/*.zsh; then
    fail "a static MLX user token remains"
fi

echo "installer checks passed"