#!/bin/env bash
#
# update-cpd-cli.sh - Automate cpd-cli version updates
# =============================================================================
# 
# This script downloads the latest cpd-cli release, extracts it, cleans up
# old versions, and updates symlinks for a seamless update process.
#
# Usage: chmod +x update-cpd-cli.sh && ./update-cpd-cli.sh
#
# Environment variables (optional):
#   CPD_CLI_PATH  - Override default installation path (/usr/local/bin)
#   CPD_SOURCE    - Override GitHub releases base URL
#
# Requirements:
#   - curl (for downloading)
#   - tar (for extraction)
#   - sudo or root access for /usr/local/bin
#
# Features:
#   - Automatic version detection from GitHub API
#   - Backup of current version before update
#   - Automatic symlink updates
#   - Detailed logging with timestamps
#   - Rollback capability (keeps old version as .OLD)
#   - Clean removal of leftover tarballs
#
# =============================================================================

set -euo pipefail

# =============================================================================
# Configuration
# =============================================================================

SOURCE_URL="https://github.com/IBM/cpd-cli/releases"
INSTALL_PATH="${CPD_CLI_PATH:-/usr/local/bin}"
TEMP_DIR="${TMPDIR:-/tmp}/cpd-cli-update"
RELEASE_FILE="cpd-cli-linux-*.tgz"
VERSION_VAR="cpd_version"

# =============================================================================
# Logging Functions
# =============================================================================

log() {
    printf '%s [INFO] %b\n"' "$(date '+%Y-%m-%d %H:%M:%S %Z')" "$*"
}

log_warn() {
    printf '%s [WARN] %b\n"' "$(date '+%Y-%m-%d %H:%M:%S %Z')" "$*"
}

log_error() {
    printf '%s [ERROR] %b\n"' "$(date '+%Y-%m-%d %H:%M:%S %Z')" "$*" >&2
}

log_success() {
    printf '%s [SUCCESS] %b\n"' "$(date '+%Y-%m-%d %H:%M:%S %Z')" "$*"
}

# =============================================================================
# Cleanup Handler
# =============================================================================

cleanup() {
    local status=$?
    if [[ $status -ne 0 ]]; then
        log_error "Script failed with exit code ${status}"
    fi
    # Always cleanup temp directory
    if [[ -d "$TEMP_DIR" ]]; then
        rm -rf "$TEMP_DIR"
    fi
    exit $status
}

trap cleanup EXIT

# =============================================================================
# Check Prerequisites
# =============================================================================

check_prerequisites() {
    # Check for curl
    if ! command -v curl &> /dev/null; then
        log_error "curl is required but not installed"
        return 1
    fi

    # Check for tar
    if ! command -v tar &> /dev/null; then
        log_error "tar is required but not installed"
        return 1
    fi

    log "Prerequisites check passed"
}

# =============================================================================
# Get Latest Release
# =============================================================================

get_latest_release() {
    log "Fetching latest release from GitHub API..."

    # Use GitHub Releases API
    local latest_url="${SOURCE_URL}/latest.json"
    local curl_timeout=30

    if ! curl -sL -o "${TEMP_DIR}/latest.json" "$latest_url"; then
        log_error "Failed to fetch latest release from GitHub"
        return 1
    fi

    # Extract version and filename from JSON
    local version filename
    version=$(jq -r '.tag_name' "${TEMP_DIR}/latest.json" 2>/dev/null) || {
        log_warn "jq not available, extracting version from URL"
        # Fallback: extract from URL
        version=$(curl -sL "${SOURCE_URL}/" \
            -H "Accept: application/json" \
            | grep -oP 'href="/releases/tag/(?<version>[^"]+)"' \
            | grep -oP '>[^<]*<' \
            | sed -E 's/.*>([^<]+)<.*/\1/')
    }

    filename="cpd-cli-linux-EE-${version}.tgz"

    if [[ -z "$version" ]]; then
        log_error "Could not determine version from GitHub API or page"
        return 1
    fi

    log "Latest release: $filename (version: $version)" >&2
    echo "$version"
    return 0
}

# =============================================================================
# Download Release
# =============================================================================

download_release() {
    local version=$1
    local filename="cpd-cli-linux-EE-${version}.tgz"
    local release_file=""  # Store actual filename from download

    log "Downloading ${filename}..."

    if curl -sL -o "${TEMP_DIR}/${filename}" \
         "${SOURCE_URL}/download/${filename}" \
         --create-dirs \
         --retry 3 \
         --retry-delay 5 \
         --max-time 600 \
         -o /dev/null; then

        # Verify download size
        local size
        size=$(stat -c%s "${TEMP_DIR}/${filename}" 2>/dev/null || stat -f%z "${TEMP_DIR}/${filename}" 2>/dev/null)

        if [[ ${size%.*} -gt 0 ]]; then
            log "Download complete: $(numfmt --to=iec ${size} 2>/dev/null || echo "${size} bytes")"
            release_file="${TEMP_DIR}/${filename}"
        else
            log_error "Downloaded file appears empty or corrupted"
            return 1
        fi
    else
        log_error "Failed to download release file"
        return 1
    fi

    echo "$release_file"
    return 0
}

# =============================================================================
# Extract Release
# =============================================================================

extract_release() {
    local tarball=$1
    local target_dir
    local version

    version=$(basename "$tarball" | sed -E 's/cpd-cli-linux-EE-([0-9.]+)\.tgz.*/\1/')
    target_dir="${TEMP_DIR}/${version}-${$(date +%s)}"

    log "Extracting to ${target_dir}..."

    # Change to temp directory and extract
    if cd "$TEMP_DIR" && tar xzf "$tarball"; then
        # Get the actual extracted directory name
        target_dir="${TEMP_DIR}/$(ls -d ${TEMP_DIR}/*/ | head -n1)"
        log "Extraction complete"
    else
        log_error "Failed to extract release"
        return 1
    fi

    echo "$target_dir"
    return 0
}

# =============================================================================
# Handle Current Installation
# =============================================================================

handle_current() {
    local installation_path="${INSTALL_PATH}"
    local current_symlink
    local current_dir

    # Check if we have a symlink
    if [[ -L "${installation_path}/cpd-cli" ]]; then
        current_symlink=readlink -f "${installation_path}/cpd-cli" 2>/dev/null
        log "Current installation: ${current_symlink}"

        # Rename to backup
        local old_backup="cpd-cli-linux-EE.$(${echo "$current_symlink" | sed -E 's|.*-([0-9.]+).*|\1|'})-OLD"
        if [[ -d "$current_symlink" ]]; then
            mv "$current_symlink" "${installation_path}/${old_backup}" 2>/dev/null || {
                log_warn "Cannot move current version directly, will clean up after update"
            }
        fi
    fi

    # Remove old symlinks if they exist
    if [[ -L "${installation_path}/cpd-cli" ]] || \
         [[ -L "${installation_path}/LICENSES" ]] || \
         [[ -L "${installation_path}/plugins" ]]; then

        log "Cleaning up old symlinks..."

        # Use sudo to remove symlinks if not root
        if [[ $EUID -ne 0 ]]; then
            sudo rm -f "${installation_path}/cpd-cli" \
                   "${installation_path}/LICENSES" \
                   "${installation_path}/plugins" 2>/dev/null || \
                log_warn "Unable to remove old symlinks without elevated privileges"
        else
            rm -f "${installation_path}/cpd-cli" \
                 "${installation_path}/LICENSES" \
                 "${installation_path}/plugins" 2>/dev/null
        fi
    fi

    return 0
}

# =============================================================================
# Install New Version
# =============================================================================

install_version() {
    local installation_path="${INSTALL_PATH}"
    local new_dir=$1
    local version

    version=$(basename "$new_dir" | sed -E 's/^.+-([0-9.]+)$/*/')

    log "Installing cpd-cli ${version}..."

    if [[ $EUID -ne 0 ]]; then
        log "Running with elevated privileges..."
        sudo mv "$new_dir" "/${installation_path}/"
    else
        mv "$new_dir" "/${installation_path}/"
    fi

    # Install symlinks
    log "Creating symlinks..."

    if [[ $EUID -ne 0 ]]; then
        sudo ln -snf "/${installation_path}/${version}/cpd-cli" "/${installation_path}/cpd-cli"
        sudo ln -snf "/${installation_path}/${version}/LICENSES" "/${installation_path}/LICENSES"
        sudo ln -snf "/${installation_path}/${version}/plugins" "/${installation_path}/plugins"
    else
        ln -snf "/${installation_path}/${version}/cpd-cli" "/${installation_path}/cpd-cli"
        ln -snf "/${installation_path}/${version}/LICENSES" "/${installation_path}/LICENSES"
        ln -snf "/${installation_path}/${version}/plugins" "/${installation_path}/plugins"
    fi

    log_success "Successfully installed cpd-cli ${version}"
}

# =============================================================================
# Cleanup Old Versions
# =============================================================================

cleanup_old() {
    local installation_path="${INSTALL_PATH}"
    local clean_patterns=("cpd-cli-linux-EE-*.tgz")
    local clean_count=0

    echo $'
=== Old Versions ==='

    for pattern in "${clean_patterns[@]}"; do
        while [[ -e "${installation_path}/${pattern}" ]]; do
            local old_version
            old_version=$(basename "${installation_path}/${pattern}" | grep -oE '[0-9.]+')

            log "Removing old version: ${old_version:-unknown} (${pattern})"
            rm -f "${installation_path}/${pattern}"
            ((clean_count++)) || true
        done
    done

    if [[ $clean_count -gt 0 ]]; then
        log "Cleaned up ${clean_count} old release(s)"
    fi

    echo "====================="
}

# =============================================================================
# Verify Installation
# =============================================================================

verify_installation() {
    local output

    echo $'
=== Verification ==='

    if [[ -L "${INSTALL_PATH}/cpd-cli" ]]; then
        output="${INSTALL_PATH}/cpd-cli" 2>/dev/null
        log_success "cpd-cli is a symlink pointing to: $(readlink -f "${INSTALL_PATH}/cpd-cli")" >&2
    else
        log_error "cpd-cli symlink was not created"
        return 1
    fi

    # Test version command
    echo "$output/" 2>/dev/null || {
        echo "$output" 2>/dev/null && log_error "Failed to execute cpd-cli"
        return 1
    }
}

# =============================================================================
# Main Function
# =============================================================================

main() {
    log "========================================"
    log "Starting cpd-cli Update Process"
    log "========================================"

    # Check prerequisites
    check_prerequisites || exit 1

    # Create temp directory
    mkdir -p "$TEMP_DIR"

    # Get latest version
    local latest_version
    latest_version=$(get_latest_release) || exit 1

    # Download release
    local download_path
    download_path=$(download_release "$latest_version") || exit 1

    # Extract release
    local extracted_dir
    extracted_dir=$(extract_release "$download_path") || exit 1

    # Handle current installation (backup if exists)
    handle_current

    # Install new version
    install_version "$extracted_dir"

    # Cleanup old tarballs and leftover dirs
    cleanup_old

    # Verify
    verify_installation || exit 1

    log "========================================"
    log_success "Update completed successfully!"
    log "New version: $(cpd-cli --version 2>/dev/null | sed -nE 's/Version: ([0-9.]+).*/\1/i')"
    log "========================================"

    return 0
}

# =============================================================================
# Execute
# =============================================================================

main "$@"