#!/usr/bin/env bash
# common.sh - Shared functions for archangel installer
# Source this file: source "$(dirname "$0")/lib/common.sh"

#############################
# Output Functions
#############################

# No color by default — use --color flag to enable
RED=''
GREEN=''
YELLOW=''
BLUE=''
BOLD=''
NC=''

enable_color() {
    RED='\033[0;31m'
    GREEN='\033[0;32m'
    YELLOW='\033[0;33m'
    BLUE='\033[0;34m'
    BOLD='\033[1m'
    NC='\033[0m'
}

info()   { echo -e "${GREEN}[INFO]${NC} $1"; }
warn()   { echo -e "${YELLOW}[WARN]${NC} $1"; }
error()  { echo -e "${RED}[ERROR]${NC} $1"; exit 1; }
step()   { echo ""; echo -e "${BOLD}==> $1${NC}"; }
prompt() { echo -e "${BLUE}$1${NC}"; }

# Log to file if LOG_FILE is set
log() {
    local msg
    msg="[$(date +'%Y-%m-%d %H:%M:%S')] $1"
    if [[ -n "$LOG_FILE" ]]; then
        echo "$msg" >> "$LOG_FILE"
    fi
}

#############################
# Validation Functions
#############################

require_root() {
    if [[ $EUID -ne 0 ]]; then
        error "This script must be run as root"
    fi
}

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

require_command() {
    command_exists "$1" || error "Required command not found: $1"
}

#############################
# Package Selection
#############################

# Print the pacstrap package list for the given filesystem, one per line.
# Common packages first, then filesystem-specific ones.
# Returns 1 for unknown filesystem.
#
# Usage: mapfile -t pkgs < <(pacstrap_packages zfs)
pacstrap_packages() {
    local fs="$1"
    local common=(
        base base-devel
        linux-lts linux-lts-headers linux-firmware
        efibootmgr
        networkmanager avahi nss-mdns openssh
        git vim sudo zsh nodejs npm
        ttf-dejavu fzf wget inetutils wireless-regdb
    )
    local fs_specific
    case "$fs" in
        zfs)   fs_specific=(zfs-dkms zfs-utils) ;;
        btrfs) fs_specific=(btrfs-progs grub grub-btrfs snapper snap-pac) ;;
        *)     return 1 ;;
    esac
    printf '%s\n' "${common[@]}" "${fs_specific[@]}"
}

#############################
# Password / Passphrase Input
#############################

# Prompt for a secret, require confirmation, enforce min length, loop
# until valid. Sets the named variable by nameref so UI output stays
# on the terminal and the caller doesn't command-substitute.
#
# Usage: prompt_password VAR_NAME "label for prompts" MIN_LEN
#   min_len of 0 disables the length check.
prompt_password() {
    local -n _out="$1"
    local label="$2"
    local min_len="${3:-0}"
    local confirm

    while true; do
        prompt "Enter $label:"
        read -rs _out
        echo ""

        prompt "Confirm $label:"
        read -rs confirm
        echo ""

        if [[ "$_out" != "$confirm" ]]; then
            warn "Passphrases do not match. Try again."
            continue
        fi
        if [[ $min_len -gt 0 && ${#_out} -lt $min_len ]]; then
            warn "Passphrase must be at least $min_len characters. Try again."
            continue
        fi
        break
    done
}

#############################
# FZF Prompts
#############################

# Check if fzf is available
has_fzf() {
    command_exists fzf
}

# Generic fzf selection
# Usage: result=$(fzf_select "prompt" "option1" "option2" ...)
fzf_select() {
    local prompt="$1"
    shift
    local options=("$@")

    if has_fzf; then
        printf '%s\n' "${options[@]}" | fzf --prompt="$prompt " --height=15 --reverse
    else
        # Fallback to simple select
        PS3="$prompt "
        select opt in "${options[@]}"; do
            if [[ -n "$opt" ]]; then
                echo "$opt"
                break
            fi
        done
    fi
}

# Multi-select with fzf
# Usage: readarray -t results < <(fzf_multi "prompt" "opt1" "opt2" ...)
fzf_multi() {
    local prompt="$1"
    shift
    local options=("$@")

    if has_fzf; then
        printf '%s\n' "${options[@]}" | fzf --prompt="$prompt " --height=20 --reverse --multi
    else
        # Fallback: just return all options (user must edit)
        printf '%s\n' "${options[@]}"
    fi
}

#############################
# Filesystem Selection
#############################

# Select filesystem type (ZFS or Btrfs)
# Sets global FILESYSTEM variable
select_filesystem() {
    step "Select Filesystem"

    local options=(
        "ZFS - Built-in encryption, best data integrity (recommended)"
        "Btrfs - Copy-on-write, LUKS encryption, GRUB snapshot boot"
    )

    local selected
    selected=$(fzf_select "Filesystem:" "${options[@]}")

    case "$selected" in
        ZFS*)
            FILESYSTEM="zfs"
            info "Selected: ZFS"
            ;;
        Btrfs*)
            FILESYSTEM="btrfs"
            info "Selected: Btrfs"
            ;;
        *)
            error "No filesystem selected"
            ;;
    esac
}

#############################
# Disk Utilities
#############################

# Get disk size in human-readable format
get_disk_size() {
    local disk="$1"
    lsblk -dno SIZE "$disk" 2>/dev/null | tr -d ' '
}

# Get disk model
get_disk_model() {
    local disk="$1"
    lsblk -dno MODEL "$disk" 2>/dev/null | tr -d ' ' | head -c 20
}

# Check if disk is in use (mounted or has holders)
disk_in_use() {
    local disk="$1"
    [[ -n "$(lsblk -no MOUNTPOINT "$disk" 2>/dev/null | grep -v '^$')" ]] && return 0
    [[ -n "$(ls /sys/block/"$(basename "$disk")"/holders/ 2>/dev/null)" ]] && return 0
    return 1
}

# List available disks (not in use)
list_available_disks() {
    local disks=()
    for disk in /dev/nvme[0-9]n[0-9] /dev/sd[a-z] /dev/vd[a-z]; do
        [[ -b "$disk" ]] || continue
        disk_in_use "$disk" && continue
        local size
        size=$(get_disk_size "$disk")
        local model
        model=$(get_disk_model "$disk")
        disks+=("$disk ($size, $model)")
    done
    printf '%s\n' "${disks[@]}"
}