#!/usr/bin/env bash
set -Eeuo pipefail

script_dir="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
release_name=Ling-3.0-Flash-CIRU-int4-Strix-native
export PATH="$HOME/.local/bin:$PATH"

usage() {
  cat <<EOF
Install the CIRU Ling 3.0 Flash gfx1151 runtime.

Human-guided install:
  bash install.sh --interactive

Non-interactive install for agents and automation:
  bash install.sh --install-root PATH --model-path PATH [OPTIONS]

Engine-only upgrade of an existing installation:
  bash install.sh --upgrade --install-root PATH

Options:
  --interactive          Ask for paths and optional actions.
  --install-root PATH    Runtime root; defaults to the current directory.
                         The vLLM environment is created at PATH/.venv.
                         PATH cannot contain whitespace or a colon because
                         the ROCr override is loaded through LD_PRELOAD.
  --model-path PATH      Exact checkpoint directory; defaults to
                         ./Ling-3.0-Flash-CIRU-int4-Strix-native.
  --install-host-deps    Run scripts/install-host-deps.sh (may use sudo).
  --download-model       Download the pinned checkpoint from this repository
                         to MODEL_PATH. Without this flag, a missing model does
                         not block the runtime installation.
                         The checkpoint is approximately 77 GB.
  --upgrade              Upgrade only the CIRU engine in an existing runtime.
                         Model weights and ling3-runtime.env are not touched.
  --skip-build           Validate/configure an already-built runtime.
  --dry-run              Print the commands and resolved paths without running them.
  --print-env            Print launch exports for the resolved paths and exit.
  -h, --help             Show this help.

The installer writes PATH/ling3-runtime.env before downloads/builds. Agents can use:
  source PATH/ling3-runtime.env
  bash scripts/run-256k.sh

Environment variables can always be supplied directly:
  VENV=PATH/.venv MODEL_PATH=MODEL_PATH bash scripts/run-256k.sh
EOF
}

die() {
  printf 'install.sh: %s\n' "$*" >&2
  exit 2
}

absolute_path() {
  local path="$1"
  case "$path" in
    '~') path="$HOME" ;;
    [~]/*) path="$HOME/${path#\~/}" ;;
    '$HOME') path="$HOME" ;;
    '$HOME/'*) path="$HOME/${path#\$HOME/}" ;;
    '${HOME}') path="$HOME" ;;
    '${HOME}/'*) path="$HOME/${path#\$\{HOME\}/}" ;;
    '$PWD') path="$PWD" ;;
    '$PWD/'*) path="$PWD/${path#\$PWD/}" ;;
    '${PWD}') path="$PWD" ;;
    '${PWD}/'*) path="$PWD/${path#\$\{PWD\}/}" ;;
  esac
  case "$path" in
    *'$'*) die "unexpanded shell variable in path: $path" ;;
  esac
  if command -v realpath >/dev/null 2>&1; then
    realpath -m -- "$path"
  elif [[ "$path" = /* ]]; then
    printf '%s\n' "$path"
  else
    printf '%s/%s\n' "$PWD" "${path#./}"
  fi
}

write_runtime_env() {
  local temporary_file="$env_file.tmp.$$"
  mkdir -p "$install_root"
  {
    printf '# Generated by %s/install.sh\n' "$script_dir"
    printf 'export VENV=%q\n' "$venv"
    printf 'export MODEL_PATH=%q\n' "$model_path"
  } >"$temporary_file"
  mv -f -- "$temporary_file" "$env_file"
}

prompt_value() {
  local variable_name="$1"
  local label="$2"
  local default_value="$3"
  local reply
  read -r -p "$label [$default_value]: " reply
  printf -v "$variable_name" '%s' "${reply:-$default_value}"
}

ask_yes_no() {
  local label="$1"
  local default_answer="$2"
  local suffix reply
  if [ "$default_answer" = yes ]; then
    suffix='[Y/n]'
  else
    suffix='[y/N]'
  fi
  while true; do
    read -r -p "$label $suffix: " reply
    reply="${reply:-$default_answer}"
    case "${reply,,}" in
      y|yes) return 0 ;;
      n|no) return 1 ;;
      *) printf 'Please answer yes or no.\n' >&2 ;;
    esac
  done
}

interactive=0
install_root=
model_path=
install_host_deps=0
download_model=0
build_runtime=1
dry_run=0
print_env=0
upgrade=0

if [ "$#" -eq 0 ]; then
  usage
  exit 0
fi

while [ "$#" -gt 0 ]; do
  case "$1" in
    --interactive)
      interactive=1
      shift
      ;;
    --install-root)
      [ "$#" -ge 2 ] || die '--install-root requires a path'
      [ -n "$2" ] || die '--install-root requires a non-empty path'
      install_root="$2"
      shift 2
      ;;
    --model-path)
      [ "$#" -ge 2 ] || die '--model-path requires a path'
      [ -n "$2" ] || die '--model-path requires a non-empty path'
      model_path="$2"
      shift 2
      ;;
    --install-host-deps)
      install_host_deps=1
      shift
      ;;
    --download-model)
      download_model=1
      shift
      ;;
    --upgrade)
      upgrade=1
      shift
      ;;
    --skip-build)
      build_runtime=0
      shift
      ;;
    --dry-run)
      dry_run=1
      shift
      ;;
    --print-env)
      print_env=1
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      die "unknown option: $1"
      ;;
  esac
done

if [ "$upgrade" = 1 ]; then
  [ -z "$model_path" ] || die '--model-path is not used with --upgrade'
  [ "$download_model" = 0 ] || die '--download-model is not used with --upgrade'
  [ "$build_runtime" = 1 ] || die '--skip-build is not used with --upgrade'
  [ "$print_env" = 0 ] || die '--print-env is not used with --upgrade'
fi

if [ "$interactive" = 1 ]; then
  [ -t 0 ] || die '--interactive requires a terminal; use explicit flags for automation'
  prompt_value install_root 'Runtime install directory' "${install_root:-$PWD}"
  if [ "$upgrade" != 1 ]; then
    prompt_value model_path 'Ling checkpoint directory' \
      "${model_path:-$PWD/$release_name}"
  fi
  if ask_yes_no 'Run the distro host-dependency installer (may use sudo)?' no; then
    install_host_deps=1
  fi
  if [ "$upgrade" != 1 ] && [ ! -f "$model_path/config.json" ]; then
    if ask_yes_no 'Checkpoint not found there. Download it from this repository (~77 GB)?' no; then
      download_model=1
    fi
  fi
fi

install_root="$(absolute_path "${install_root:-$PWD}")"
case "$install_root" in
  *[[:space:]:]*)
    die "install root cannot contain whitespace or ':' because ROCr is loaded through LD_PRELOAD: $install_root"
    ;;
esac
venv="$install_root/.venv"
env_file="$install_root/ling3-runtime.env"
if [ "$upgrade" != 1 ]; then
  model_path="$(absolute_path "${model_path:-$PWD/$release_name}")"
fi

if [ "$print_env" = 1 ]; then
  printf 'export VENV=%q\n' "$venv"
  printf 'export MODEL_PATH=%q\n' "$model_path"
  exit 0
fi

if [ "$upgrade" = 1 ]; then
  printf 'CIRU Ling engine-only upgrade\n'
  printf '  package: %s\n  install root: %s\n  venv: %s\n' \
    "$script_dir" "$install_root" "$venv"
  printf '  host dependencies: %s\n  model files: preserved\n' "$install_host_deps"
else
  printf 'CIRU Ling runtime installation\n'
  printf '  package: %s\n  install root: %s\n  venv: %s\n  model: %s\n' \
    "$script_dir" "$install_root" "$venv" "$model_path"
  printf '  host dependencies: %s\n  download model: %s\n  build runtime: %s\n' \
    "$install_host_deps" "$download_model" "$build_runtime"
fi

if [ "$interactive" = 1 ] && ! ask_yes_no 'Continue with these settings?' yes; then
  printf 'Installation cancelled.\n'
  exit 0
fi

if [ "$dry_run" = 1 ]; then
  if [ "$install_host_deps" = 1 ]; then
    printf 'DRY RUN: bash %q\n' "$script_dir/scripts/install-host-deps.sh"
  fi
  if [ "$upgrade" = 1 ]; then
    printf 'DRY RUN: validate %q and preserve model files/configuration\n' "$venv"
    printf 'DRY RUN: bash %q %q\n' \
      "$script_dir/scripts/install-rocr-idle-fix.sh" "$install_root"
    exit 0
  fi
  if [ "$download_model" = 1 ]; then
    printf 'DRY RUN: bash %q --model-path %q\n' \
      "$script_dir/scripts/download-model.sh" "$model_path"
  fi
  if [ "$build_runtime" = 1 ]; then
    printf 'DRY RUN: bash %q %q\n' \
      "$script_dir/scripts/build-vllm-gfx1151.sh" "$install_root"
  fi
  printf 'DRY RUN: bash %q %q\n' \
    "$script_dir/scripts/install-rocr-idle-fix.sh" "$install_root"
  printf 'DRY RUN: write %q\n' "$env_file"
  exit 0
fi

if [ "$upgrade" = 1 ]; then
  [ -x "$venv/bin/python" ] || \
    die "existing CIRU runtime is missing Python: $venv/bin/python"
  [ -x "$venv/bin/vllm" ] || \
    die "existing CIRU runtime is missing vLLM: $venv/bin/vllm"
  if [ "$install_host_deps" = 1 ]; then
    bash "$script_dir/scripts/install-host-deps.sh"
  fi
  bash "$script_dir/scripts/install-rocr-idle-fix.sh" "$install_root"
  printf '\nEngine upgrade complete. Model files and ling3-runtime.env were unchanged.\n'
  printf 'Restart the CIRU launcher or service to load the corrected ROCr runtime.\n'
  printf 'Emergency rollback: set CIRU_DISABLE_ROCR_IDLE_FIX=1 before launching.\n'
  exit 0
fi

# The environment file contains only resolved paths, so create it before any
# download or build. A failed dependency/build step must still leave users a
# correct, sourceable record of the intended runtime and model locations.
write_runtime_env
printf 'Prepared environment file: %s\n' "$env_file"

if [ "$download_model" != 1 ] && [ ! -f "$model_path/config.json" ]; then
  printf 'Model download skipped; the runtime will be installed without weights.\n'
  printf 'Expected future model path: %s\n' "$model_path"
fi

if [ "$install_host_deps" = 1 ]; then
  bash "$script_dir/scripts/install-host-deps.sh"
fi

if [ "$download_model" = 1 ]; then
  bash "$script_dir/scripts/download-model.sh" --model-path "$model_path"
fi

if [ "$build_runtime" = 1 ]; then
  bash "$script_dir/scripts/build-vllm-gfx1151.sh" "$install_root"
fi
bash "$script_dir/scripts/install-rocr-idle-fix.sh" "$install_root"

[ -x "$venv/bin/python" ] || die "runtime Python is missing after installation: $venv/bin/python"
[ -x "$venv/bin/vllm" ] || die "vLLM launcher is missing after installation: $venv/bin/vllm"
if [ -f "$model_path/config.json" ]; then
  model_ready=1
elif [ "$download_model" = 1 ]; then
  die "model download completed without the expected config: $model_path/config.json"
else
  model_ready=0
fi

printf '\nInstallation complete.\n'
printf 'Environment file: %s\n\n' "$env_file"
if [ "$model_ready" = 1 ]; then
  printf 'Launch the native 256K profile:\n'
  printf '  source %q\n  bash %q\n\n' "$env_file" "$script_dir/scripts/run-256k.sh"
else
  printf 'The optional model download was skipped. Download it later with:\n'
  printf '  bash %q --model-path %q\n\n' \
    "$script_dir/scripts/download-model.sh" "$model_path"
  printf 'Then launch with:\n'
  printf '  source %q\n  bash %q\n\n' "$env_file" "$script_dir/scripts/run-256k.sh"
fi
printf 'For agents or automation:\n'
printf '  export VENV=%q\n  export MODEL_PATH=%q\n' "$venv" "$model_path"
if [ "$model_ready" = 1 ]; then
  printf '  bash %q\n' "$script_dir/scripts/run-256k.sh"
else
  printf '  # Provide the checkpoint before running %q\n' "$script_dir/scripts/run-256k.sh"
fi