#!/usr/bin/env bash

set -u

ROOT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
CONFIG_DIR="${FFX_CONFIG_DIR:-${HOME}/.local/etc}"
CONFIG_FILE="${FFX_CONFIG_FILE:-${CONFIG_DIR}/ffx.json}"
VAR_DIR="${FFX_VAR_DIR:-${HOME}/.local/var/ffx}"
LOG_DIR="${FFX_LOG_DIR:-${HOME}/.local/var/log}"
DATABASE_FILE="${FFX_DATABASE_FILE:-${VAR_DIR}/ffx.db}"
SUBTITLES_BASE_DIR="${FFX_SUBTITLES_BASE_DIR:-${HOME}/.local/var/sync/subtitles}"
FFX_PYTHON="${FFX_PYTHON:-${HOME}/.local/share/ffx.venv/bin/python}"
CONFIG_TEMPLATE_FILE="${FFX_CONFIG_TEMPLATE:-${ROOT_DIR}/assets/ffx.json.j2}"

CHECK_ONLY=0
WITH_TESTS=0

MUTATIONS=0
INSTALL_FAILURES=0
READINESS_FAILURES=0

MISSING_REQUIRED_SYSTEM=()
MISSING_OPTIONAL_SYSTEM=()

COLOR_RESET=""
COLOR_GREEN=""
COLOR_YELLOW=""
COLOR_RED=""

if [ -t 1 ]; then
    COLOR_RESET="$(printf '\033[0m')"
    COLOR_GREEN="$(printf '\033[32m')"
    COLOR_YELLOW="$(printf '\033[33m')"
    COLOR_RED="$(printf '\033[31m')"
fi

usage() {
    cat <<EOF
Usage: $(basename "$0") [--check] [--with-tests] [--help]

Prepare the local workstation environment for an already installed FFX bundle.

Options:
  --check           Report readiness only. Do not create, install, or modify.
  --with-tests      Include test-related notes while preparing system dependencies and local config.
  --help            Show this help text.

Environment overrides:
  FFX_CONFIG_DIR    Override the parent directory for the seeded ffx.json file.
  FFX_CONFIG_FILE   Override the seeded config file path directly.
  FFX_VAR_DIR       Override the default data directory.
  FFX_LOG_DIR       Override the default log directory.
  FFX_DATABASE_FILE Override the database path written into a newly seeded config.
  FFX_SUBTITLES_BASE_DIR Override the default subtitles base directory written into a newly seeded config.
  FFX_PYTHON        Override the bundle venv Python used to render the seeded config.
  FFX_CONFIG_TEMPLATE Override the Jinja2 template path used to seed the config.

Notes:
  - tools/setup.sh is the first installation step and owns bundle venv setup.
  - This script is the second step and owns system dependencies plus local config.
  - After the bundle is installed, the aligned CLI wrapper is: ffx configure_workstation
  - Python test packages are installed by tools/setup.sh --with-tests, not here.
EOF
}

status_ok() {
    printf '%sok%s' "${COLOR_GREEN}" "${COLOR_RESET}"
}

status_warn() {
    printf '%swarn%s' "${COLOR_YELLOW}" "${COLOR_RESET}"
}

status_fail() {
    printf '%sfailed%s' "${COLOR_RED}" "${COLOR_RESET}"
}

report_component() {
    local level="$1"
    local label="$2"
    local detail="$3"
    local rendered_status=""

    case "${level}" in
        ok)
            rendered_status="$(status_ok)"
            ;;
        warn)
            rendered_status="$(status_warn)"
            ;;
        *)
            rendered_status="$(status_fail)"
            ;;
    esac

    printf '[%s] %s%s\n' "${rendered_status}" "${label}" "${detail:+: $detail}"
}

command_exists() {
    command -v "$1" >/dev/null 2>&1
}

check_command_component() {
    command_exists "$2"
}

check_tmdb_key() {
    [ -n "${TMDB_API_KEY:-}" ]
}

check_seeded_dir() {
    [ -d "$1" ]
}

check_seeded_file() {
    [ -f "$1" ]
}

component_detail() {
    case "$1" in
        git|python3|ffmpeg|ffprobe|cpulimit)
            command -v "$1" || printf "command '%s' not found" "$1"
            ;;
        tmdb-key)
            if check_tmdb_key; then
                printf 'TMDB_API_KEY is set'
            else
                printf 'TMDB_API_KEY is unset; TMDB-backed flows will be skipped or fail'
            fi
            ;;
        config-dir)
            if check_seeded_dir "${CONFIG_DIR}"; then
                printf '%s' "${CONFIG_DIR}"
            else
                printf 'missing; prep can create it'
            fi
            ;;
        var-dir)
            if check_seeded_dir "${VAR_DIR}"; then
                printf '%s' "${VAR_DIR}"
            else
                printf 'missing; prep can create it'
            fi
            ;;
        log-dir)
            if check_seeded_dir "${LOG_DIR}"; then
                printf '%s' "${LOG_DIR}"
            else
                printf 'missing; prep can create it'
            fi
            ;;
        subtitles-base-dir)
            if check_seeded_dir "${SUBTITLES_BASE_DIR}"; then
                printf '%s' "${SUBTITLES_BASE_DIR}"
            else
                printf 'missing; prep can create it'
            fi
            ;;
        ffx-config)
            if check_seeded_file "${CONFIG_FILE}"; then
                printf '%s' "${CONFIG_FILE}"
            else
                printf 'missing; prep can seed a default non-destructively'
            fi
            ;;
    esac
}

report_toolchain_component() {
    local label="$1"
    local command_name="$2"
    local required="$3"

    if check_command_component "${label}" "${command_name}" "${required}"; then
        report_component ok "${label}" "$(component_detail "${command_name}")"
    else
        if [ "${required}" = "required" ]; then
            report_component failed "${label}" "$(component_detail "${command_name}")"
            MISSING_REQUIRED_SYSTEM+=("${command_name}")
            READINESS_FAILURES=$((READINESS_FAILURES + 1))
        else
            report_component warn "${label}" "$(component_detail "${command_name}")"
            MISSING_OPTIONAL_SYSTEM+=("${command_name}")
        fi
    fi
}

report_tmdb_component() {
    if check_tmdb_key; then
        report_component ok "TMDB API key" "$(component_detail tmdb-key)"
    else
        report_component warn "TMDB API key" "$(component_detail tmdb-key)"
    fi
}

report_seeded_component() {
    local label="$1"
    local key="$2"
    local required="$3"
    local ok=1

    case "${key}" in
        config-dir)
            check_seeded_dir "${CONFIG_DIR}" || ok=0
            ;;
        var-dir)
            check_seeded_dir "${VAR_DIR}" || ok=0
            ;;
        log-dir)
            check_seeded_dir "${LOG_DIR}" || ok=0
            ;;
        subtitles-base-dir)
            check_seeded_dir "${SUBTITLES_BASE_DIR}" || ok=0
            ;;
        ffx-config)
            check_seeded_file "${CONFIG_FILE}" || ok=0
            ;;
    esac

    if [ "${ok}" -eq 1 ]; then
        report_component ok "${label}" "$(component_detail "${key}")"
    else
        if [ "${required}" = "required" ]; then
            report_component failed "${label}" "$(component_detail "${key}")"
            READINESS_FAILURES=$((READINESS_FAILURES + 1))
        else
            report_component warn "${label}" "$(component_detail "${key}")"
        fi
    fi
}

print_dependency_status() {
    READINESS_FAILURES=0
    MISSING_REQUIRED_SYSTEM=()
    MISSING_OPTIONAL_SYSTEM=()

    echo "Dependency status:"
    report_toolchain_component "git" "git" "required"
    report_toolchain_component "python3" "python3" "required"
    report_toolchain_component "ffmpeg" "ffmpeg" "required"
    report_toolchain_component "ffprobe" "ffprobe" "required"
    report_toolchain_component "cpulimit" "cpulimit" "required"
    report_tmdb_component
}

print_seeded_file_status() {
    echo "Seeded local files:"
    report_seeded_component "Config dir" "config-dir" "optional"
    report_seeded_component "Var dir" "var-dir" "optional"
    report_seeded_component "Log dir" "log-dir" "optional"
    report_seeded_component "Subtitles base dir" "subtitles-base-dir" "optional"
    report_seeded_component "ffx config" "ffx-config" "optional"
}

print_test_package_status() {
    if [ "${WITH_TESTS}" -eq 0 ]; then
        return 0
    fi

    echo "Test environment notes:"
    report_component ok "system test dependencies" "no extra system packages beyond the standard runtime toolchain"
    report_component ok "Python test packages" "install via tools/setup.sh --with-tests"
}

detect_package_manager() {
    if command_exists apt-get; then
        printf 'apt-get\n'
        return 0
    fi
    if command_exists pacman; then
        printf 'pacman\n'
        return 0
    fi
    return 1
}

run_root_command() {
    if [ "${EUID}" -eq 0 ]; then
        "$@"
    elif command_exists sudo; then
        sudo "$@"
    else
        return 1
    fi
}

install_system_requirements() {
    local package_manager

    if ! package_manager="$(detect_package_manager)"; then
        printf 'No supported package manager found for automatic preparation.\n' >&2
        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
        return 1
    fi

    case "${package_manager}" in
        apt-get)
            printf 'Installing missing system dependencies via apt-get...\n'
            if ! run_root_command apt-get update; then
                printf 'apt-get update failed.\n' >&2
                INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
                return 1
            fi
            if ! run_root_command apt-get install -y git python3 ffmpeg cpulimit; then
                printf 'apt-get install failed.\n' >&2
                INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
                return 1
            fi
            ;;
        pacman)
            printf 'Installing missing system dependencies via pacman...\n'
            if ! run_root_command pacman -Sy --noconfirm git python ffmpeg cpulimit; then
                printf 'pacman install failed.\n' >&2
                INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
                return 1
            fi
            ;;
    esac

    MUTATIONS=$((MUTATIONS + 1))
    return 0
}

render_default_config() {
    local output_path="$1"
    local temporary_output_path=""

    if [ ! -x "${FFX_PYTHON}" ]; then
        printf 'Missing bundle Python interpreter at %s.\n' "${FFX_PYTHON}" >&2
        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
        return 1
    fi

    if [ ! -f "${CONFIG_TEMPLATE_FILE}" ]; then
        printf 'Missing FFX config template at %s.\n' "${CONFIG_TEMPLATE_FILE}" >&2
        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
        return 1
    fi

    if ! temporary_output_path="$(mktemp "${output_path}.tmp.XXXXXX")"; then
        printf 'Failed to create a temporary config file next to %s.\n' "${output_path}" >&2
        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
        return 1
    fi

    if ! FFX_CONFIG_TEMPLATE_FILE="${CONFIG_TEMPLATE_FILE}" \
        FFX_REPO_ROOT="${ROOT_DIR}" \
        FFX_DATABASE_PATH="${DATABASE_FILE}" \
        FFX_LOG_DIRECTORY="${LOG_DIR}" \
        FFX_SUBTITLES_DIRECTORY="${SUBTITLES_BASE_DIR}" \
        "${FFX_PYTHON}" - >"${temporary_output_path}" <<'PY'
from __future__ import annotations

import json
import os
import sys
from pathlib import Path

from jinja2 import Environment, FileSystemLoader, StrictUndefined

repo_root = Path(os.environ["FFX_REPO_ROOT"])
src_root = repo_root / "src"
if str(src_root) not in sys.path:
    sys.path.insert(0, str(src_root))

from ffx.constants import (
    DEFAULT_SHOW_INDEX_EPISODE_DIGITS,
    DEFAULT_SHOW_INDEX_SEASON_DIGITS,
    DEFAULT_SHOW_INDICATOR_EPISODE_DIGITS,
    DEFAULT_SHOW_INDICATOR_SEASON_DIGITS,
)

template_path = Path(os.environ["FFX_CONFIG_TEMPLATE_FILE"])
environment = Environment(
    loader=FileSystemLoader(str(template_path.parent)),
    undefined=StrictUndefined,
    autoescape=False,
    keep_trailing_newline=True,
)
template = environment.get_template(template_path.name)

sys.stdout.write(
    template.render(
        database_path_json=json.dumps(os.environ["FFX_DATABASE_PATH"]),
        log_directory_json=json.dumps(os.environ["FFX_LOG_DIRECTORY"]),
        subtitles_directory_json=json.dumps(os.environ["FFX_SUBTITLES_DIRECTORY"]),
        default_index_season_digits=DEFAULT_SHOW_INDEX_SEASON_DIGITS,
        default_index_episode_digits=DEFAULT_SHOW_INDEX_EPISODE_DIGITS,
        default_indicator_season_digits=DEFAULT_SHOW_INDICATOR_SEASON_DIGITS,
        default_indicator_episode_digits=DEFAULT_SHOW_INDICATOR_EPISODE_DIGITS,
    )
)
PY
    then
        rm -f "${temporary_output_path}"
        printf 'Failed to render ffx config from template %s.\n' "${CONFIG_TEMPLATE_FILE}" >&2
        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
        return 1
    fi

    if ! mv "${temporary_output_path}" "${output_path}"; then
        rm -f "${temporary_output_path}"
        printf 'Failed to move rendered ffx config into place at %s.\n' "${output_path}" >&2
        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
        return 1
    fi

    return 0
}

seed_default_config() {
    if [ "${CHECK_ONLY}" -eq 1 ]; then
        return 0
    fi

    local created_any=0

    if [ ! -d "${CONFIG_DIR}" ]; then
        printf 'Creating config dir at %s...\n' "${CONFIG_DIR}"
        if ! mkdir -p "${CONFIG_DIR}"; then
            printf 'Failed to create config dir at %s.\n' "${CONFIG_DIR}" >&2
            INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
            return 1
        fi
        created_any=1
    fi

    if [ ! -d "${VAR_DIR}" ]; then
        printf 'Creating var dir at %s...\n' "${VAR_DIR}"
        if ! mkdir -p "${VAR_DIR}"; then
            printf 'Failed to create var dir at %s.\n' "${VAR_DIR}" >&2
            INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
            return 1
        fi
        created_any=1
    fi

    if [ ! -d "${LOG_DIR}" ]; then
        printf 'Creating log dir at %s...\n' "${LOG_DIR}"
        if ! mkdir -p "${LOG_DIR}"; then
            printf 'Failed to create log dir at %s.\n' "${LOG_DIR}" >&2
            INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
            return 1
        fi
        created_any=1
    fi

    if [ ! -d "${SUBTITLES_BASE_DIR}" ]; then
        printf 'Creating subtitles base dir at %s...\n' "${SUBTITLES_BASE_DIR}"
        if ! mkdir -p "${SUBTITLES_BASE_DIR}"; then
            printf 'Failed to create subtitles base dir at %s.\n' "${SUBTITLES_BASE_DIR}" >&2
            INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
            return 1
        fi
        created_any=1
    fi

    if [ ! -f "${CONFIG_FILE}" ]; then
        printf 'Seeding ffx config at %s...\n' "${CONFIG_FILE}"
        if ! render_default_config "${CONFIG_FILE}"; then
            return 1
        fi
        created_any=1
    fi

    if [ "${created_any}" -eq 1 ]; then
        MUTATIONS=$((MUTATIONS + 1))
    fi

    return 0
}

parse_args() {
    while [ "$#" -gt 0 ]; do
        case "$1" in
            --check)
                CHECK_ONLY=1
                ;;
            --with-tests)
                WITH_TESTS=1
                ;;
            --help|-h)
                usage
                exit 0
                ;;
            *)
                printf 'Unknown option: %s\n\n' "$1" >&2
                usage >&2
                exit 2
                ;;
        esac
        shift
    done
}

main() {
    parse_args "$@"

    print_dependency_status

    if [ "${CHECK_ONLY}" -eq 0 ] && [ "${#MISSING_REQUIRED_SYSTEM[@]}" -gt 0 ]; then
        install_system_requirements

        echo
        print_dependency_status
    fi

    echo
    print_seeded_file_status

    echo
    print_test_package_status

    if [ "${CHECK_ONLY}" -eq 0 ]; then
        seed_default_config
        echo
        print_dependency_status
        echo
        print_seeded_file_status
        echo
        print_test_package_status
    fi

    echo
    if [ "${INSTALL_FAILURES}" -gt 0 ]; then
        echo "One or more install steps failed; see the status checks above." >&2
        return 1
    fi

    if [ "${READINESS_FAILURES}" -gt 0 ]; then
        if [ "${CHECK_ONLY}" -eq 1 ]; then
            echo "Required system prerequisites are incomplete." >&2
        else
            echo "Required components are still missing after preparation." >&2
        fi
        return 1
    fi

    if [ "${CHECK_ONLY}" -eq 1 ]; then
        echo "The FFX preparation environment is ready."
    elif [ "${MUTATIONS}" -gt 0 ]; then
        echo "The FFX preparation environment is ready."
    else
        echo "The FFX preparation environment is already prepared."
    fi

    return 0
}

main "$@"