#!/bin/bash

set -euo pipefail

arch=$(uname -m)

if [ "$(id -u)" -eq 0 ]; then
    echo "This script is not meant to be run as root."
    echo "It will create a home directory inside the rootfs for your current user, and if that user is root, this might not be what you want."
    read -p "Are you sure you want to continue as root? (y/N) " -n 1 -r
    echo
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        exit 1
    fi
fi

if [ "$arch" != "riscv64" ]; then
    echo "You are not on 64-bit RISC-V. felix86 only works on 64-bit RISC-V."
    exit 1
fi

missing=()
for cmd in curl tar unzip sudo jq patchelf; do
    command -v "$cmd" >/dev/null 2>&1 || missing+=("$cmd")
done

if [ ${#missing[@]} -gt 0 ]; then
    echo "Error: missing required tools: ${missing[*]}"
    echo "  Ubuntu/Debian: sudo apt install ${missing[*]}"
    echo "  Arch:          sudo pacman -S ${missing[*]}"
    exit 1
fi

if [ -z "$HOME" ] || [ ! -d "$HOME" ]; then
    echo "Error: \$HOME is not set or not a valid directory."
    exit 1
fi

if [ -z "$USER" ]; then
    echo "\$USER is not set"
    exit 1
fi

INSTALLATION_DIR="/opt/felix86"
FILE="$INSTALLATION_DIR/felix86"

check_url() {
  local url="$1"

  if ! curl --output /dev/null --silent --head --fail "$url"; then
    echo "URL is invalid or unreachable: $url"
    exit 1
  else
    return 0
  fi
}

select_release_url() {
  local url_list
  check_url "https://cdn.felix86.com/releases/meta.txt"
  url_list=$(curl -s https://cdn.felix86.com/releases/meta.txt)

  if [[ -z "$url_list" ]]; then
    echo "Failed to fetch the releases list or it's empty."
    return 1
  fi

  local total_lines
  total_lines=$(echo "$url_list" | wc -l)
  if (( total_lines > 5 )); then
    echo "Failed to parse https://cdn.felix86.com/releases/meta.txt"
    return 1
  fi

  local entries=()
  while IFS= read -r line && [[ ${#entries[@]} -lt 5 ]]; do
    entries+=("$line")
  done <<< "$url_list"

  if [[ ${#entries[@]} -eq 0 ]]; then
    echo "No valid entries found."
    return 1
  fi

  echo "┌───────────────────────────────────────┐"
  echo "│   Welcome to the felix86 installer!   │"
  echo "├───────────────────────────────────────┤"
  echo "│                                       │"
  echo "│  Please choose the version you'd      │"
  echo "│  like to install                      │"
  echo "│                                       │"
  echo "└───────────────────────────────────────┘"
  echo 

  for i in "${!entries[@]}"; do
    local version="${entries[$i]%% *}"
    local display="felix86 $version"
    local extra=""
    if [[ $i -eq 0 ]]; then
        extra="[Default]"
    fi
    printf " %d) %-17s %s\n" $((i+1)) "$display" "$extra"
  done

  local latest_index=$(( ${#entries[@]} + 1 ))
  printf " %d) %-17s %s\n" $latest_index "Nightly version" "[Unstable]"

  local choose_nightly_index=$(( ${#entries[@]} + 2 ))
  printf " %d) %s\n" $choose_nightly_index "Choose specific build"
  echo

  local choice
  while true; do
    read -p "Choose a release (1-$choose_nightly_index) [default: 1]: " choice
    choice=${choice:-1}
    if [[ "$choice" =~ ^[1-9][0-9]*$ ]] && (( choice >= 1 && choice <= choose_nightly_index )); then
      break
    else
      echo "Invalid selection. Please choose a number between 1 and $choose_nightly_index."
    fi
  done

  if (( choice == latest_index )); then
    echo "Fetching latest artifact link..."
    ver="latest"
    nightly="https://nightly.link/OFFTKP/felix86/workflows/build/master"
    FELIX86_LINK="$nightly/linux_artifact.zip"
  elif (( choice == choose_nightly_index )); then
    echo "Fetching latest artifacts..."
    github_api_link="https://api.github.com/repos/OFFTKP/felix86/actions/artifacts?name=linux_artifact&per_page=100"
    github_api_response=$(curl -s -L -H "Accept: application/vnd.github+json" -H "X-GitHub-Api-Version: 2022-11-28" "$github_api_link" | jq '.artifacts[] | select(.workflow_run.head_branch == "master")')
    if [ -z "$github_api_response" ]; then
      echo "No artifacts found on master branch"
      exit 1
    fi
    artifacts_array=$(echo "$github_api_response" | jq -s '.')
    artifacts_length=$(echo "$artifacts_array" | jq 'length')
    echo "Available artifacts:"
    echo "$artifacts_array" | jq -r 'to_entries[] | "\(.key + 1)) felix86 commit \(.value.workflow_run.head_sha[0:7]) from \(.value.created_at | strptime("%Y-%m-%dT%H:%M:%SZ") | strftime("%Y-%m-%d %H:%M"))"'
    echo ""
    read -p "Select artifact (1-$artifacts_length): " selection
    if [[ "$selection" =~ ^[0-9]+$ ]] && [ "$selection" -ge 1 ] && [ "$selection" -le "$artifacts_length" ]; then
      selected_id=$(echo "$artifacts_array" | jq -r ".[$((selection-1))].workflow_run.id")
      if [ -z "$selected_id" ]; then
        echo "Failed to get artifact id?"
        exit 1
      fi
      FELIX86_LINK=https://nightly.link/OFFTKP/felix86/actions/runs/$selected_id/linux_artifact.zip
    else
      echo "Invalid selection"
      exit 1
    fi
  else
    ver=${entries[$((choice-1))]}
    selected="https://github.com/OFFTKP/felix86/releases/download/$ver/felix86.$ver.zip"
    FELIX86_LINK="${selected#* }"
  fi
}

select_release_url

echo "Downloading felix86 from $FELIX86_LINK ..."
mkdir -p /tmp/felix86_artifact
curl -L "$FELIX86_LINK" -o /tmp/felix86_artifact/archive.zip
echo "Unzipping..."
unzip -o -d /tmp/felix86_artifact /tmp/felix86_artifact/archive.zip
rm /tmp/felix86_artifact/archive.zip
echo "Moving felix86 executable to $FILE, requesting permission..."
sudo mkdir -p "$INSTALLATION_DIR"
sudo mkdir -p "$INSTALLATION_DIR/lib"
sudo mkdir -p "$INSTALLATION_DIR/lib/x86_64-linux-gnu"
sudo mkdir -p "$INSTALLATION_DIR/lib/riscv64-linux-gnu"
sudo mkdir -p "$INSTALLATION_DIR/licenses"

sudo mv /tmp/felix86_artifact/felix86 $FILE
if [ -f "/tmp/felix86_artifact/felix86.png" ]; then
  sudo mkdir -p "$INSTALLATION_DIR/icons"
  sudo mv "/tmp/felix86_artifact/felix86.png" "$INSTALLATION_DIR/icons/felix86.png"
fi
sudo mv /tmp/felix86_artifact/lib/x86_64-linux-gnu/* "$INSTALLATION_DIR/lib/x86_64-linux-gnu/"

echo "Downloading custom glibc fork..."
mkdir -p /tmp/felix86_artifact/glibc
FELIX86_GLIBC_LINK="https://github.com/felix86-emu/glibc/releases/download/2.4.3-felix86/glibc-felix86.zip"
curl -fsSL "$FELIX86_GLIBC_LINK" -o /tmp/felix86_artifact/glibc/glibc.zip
unzip -o -d /tmp/felix86_artifact/glibc /tmp/felix86_artifact/glibc/glibc.zip
rm /tmp/felix86_artifact/glibc/glibc.zip
sudo mv /tmp/felix86_artifact/glibc/lib/riscv64-linux-gnu/* "$INSTALLATION_DIR/lib/riscv64-linux-gnu/"
sudo mv /tmp/felix86_artifact/glibc/licenses/* "$INSTALLATION_DIR/licenses"
rmdir /tmp/felix86_artifact/glibc/lib/riscv64-linux-gnu
rmdir /tmp/felix86_artifact/glibc/lib
rmdir /tmp/felix86_artifact/glibc/licenses
rmdir /tmp/felix86_artifact/glibc

sudo ln -sf "$FILE" /usr/bin/felix86
sudo patchelf --set-interpreter "$INSTALLATION_DIR/lib/riscv64-linux-gnu/ld-linux-riscv64-lp64d.so.1" \
         --add-rpath "$INSTALLATION_DIR/lib/riscv64-linux-gnu" \
         "$FILE"
sudo chown 0:0 "$FILE"
sudo chmod +x "$FILE"
sudo chown -R 0:0 "$INSTALLATION_DIR/lib"
echo "Successfully installed felix86 at $FILE and libraries at $INSTALLATION_DIR/lib"
felix86 --set-thunks $INSTALLATION_DIR/lib

rmdir /tmp/felix86_artifact/lib/x86_64-linux-gnu
rmdir /tmp/felix86_artifact/lib
rmdir /tmp/felix86_artifact

current_rootfs=$(felix86 -g)
INSTALL_ROOTFS=1
if [[ -n "$current_rootfs" && -d "$current_rootfs" ]]; then
  echo "Looks like you already have a rootfs at $current_rootfs"
  read -p "Do you want to install a new rootfs anyway? (y/N) " -n 1 -r
  echo
  if [[ ! $REPLY =~ ^[Yy]$ ]]; then
      INSTALL_ROOTFS=0
  fi
fi

if [[ "$INSTALL_ROOTFS" == "1" ]]; then
  bash <(curl -s https://install.felix86.com/rootfs.sh)
fi

NEW_ROOTFS=$(felix86 -g)

# Finally register felix86 in binfmt_misc
sudo --preserve-env=HOME felix86 --binfmt-misc

echo "Running a test program..."

# Let's try to run a test program
set +e
FELIX86_QUIET=1 felix86 "$NEW_ROOTFS/bin/bash" -c "exit 42"
exit_code=$?

# If everything went fine, felix86 should return 42
if [ "$exit_code" -ne 42 ]; then
    echo "felix86 failed to run a simple program -- may not have installed correctly?"
    echo "Running again with logging enabled:"
    felix86 "$NEW_ROOTFS/bin/bash" -c "exit 42"
    exit 1
fi

echo "felix86 installed successfully"
echo
echo

echo "┌───────────────────────────────────────┐"
echo "│       felix86 is now installed!       │"
echo "├───────────────────────────────────────┤"
echo "│                                       │"
echo "│ To enter an emulated bash, use:       │"
echo "│                                       │"
echo "│ felix86 --shell   (25.12 and later)   │"
echo "│                                       │"
echo "│   OR                                  │"
echo "│                                       │"
echo "│ felix86 /path/to/rootfs/bin/bash      │"
echo "│                                       │"
echo "├───────────────────────────────────────┤"
echo "│                                       │"
echo "│ Alternatively, run programs directly: │"
echo "│                                       │"
echo "│ /path/to/rootfs/MyGame.AppImage       │"
echo "│                                       │"
echo "└───────────────────────────────────────┘"

if ! felix86 -d; then
  echo "Failed binfmt_misc installation check"
  echo "felix86 is currently not used as the default emulator for x86 applications"
  echo "If you have other x86 emulators registered then you will need to unregister them"
  echo "Example of unregistering an emulator: sudo sh -c \"echo -1 > /proc/sys/fs/binfmt_misc/qemu-x86_64\""
  echo "To make this change permanent, make sure to remove the respective file from one of these directories:"
  echo "  /etc/binfmt.d"
  echo "  /run/binfmt.d"
  echo "  /usr/local/lib/binfmt.d"
  echo "  /usr/lib/binfmt.d"
  echo "After you're done, to register felix86, run: sudo --preserve-env=HOME $FILE -b"
  echo "If you don't register to binfmt_misc, some apps like sudo (needed by AppImages) will not work"
fi