#!/usr/bin/env bash

set -Eeuo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
DOTFILES_DIR="$(cd -- "$SCRIPT_DIR/../dotfiles" && pwd)"

BACKUP_ROOT="$HOME/.dotfiles-backup"
BACKUP_DIR=""

log() {
    printf '[*] %s\n' "$*"
}

warn() {
    printf '[!] %s\n' "$*" >&2
}

die() {
    printf '[✗] %s\n' "$*" >&2
    exit 1
}

# ------------------------------------------------------------
# Vérifications
# ------------------------------------------------------------

if [[ "${EUID}" -eq 0 ]]; then
    die "Ne lance pas ce script en root."
fi

if [[ ! -d "$DOTFILES_DIR" ]]; then
    die "Répertoire dotfiles introuvable : $DOTFILES_DIR"
fi

# ------------------------------------------------------------
# Dépendances système
# ------------------------------------------------------------

log "Mise à jour des paquets apt..."
#sudo apt update

log "Installation des dépendances..."
#sudo apt install -y apt-transport-https curl git gnupg stow zsh fzf zoxide

# ------------------------------------------------------------
# Rust / Cargo
# ------------------------------------------------------------

if ! command -v cargo >/dev/null 2>&1; then
    log "Cargo introuvable, installation de rustup..."

    curl \
        --proto '=https' \
        --tlsv1.2 \
        -sSf \
        https://sh.rustup.rs |
        sh -s -- -y
fi

if [[ -f "$HOME/.cargo/env" ]]; then
    # shellcheck disable=SC1091
    source "$HOME/.cargo/env"
fi

if ! command -v cargo >/dev/null 2>&1; then
    echo "Cargo est toujours introuvable après l'installation de Rust."
    exit 1 
fi

# ------------------------------------------------------------
# Spaceship
#
# Logiciel :
#   ~/.zsh/spaceship-prompt
#
# Configuration :
#   ~/.zsh/spaceship.zsh
# ------------------------------------------------------------

SPACESHIP_DIR="$HOME/.zsh/spaceship-prompt"

if [[ -d "$SPACESHIP_DIR/.git" ]]; then
    log "Spaceship déjà installé, mise à jour..."

    git -C "$SPACESHIP_DIR" pull --ff-only

elif [[ -e "$SPACESHIP_DIR" ]]; then
    die "$SPACESHIP_DIR existe mais n'est pas un dépôt Git."

else
    log "Installation de Spaceship..."

    mkdir -p "$HOME/.zsh"

    git clone \
        --depth=1 \
        https://github.com/spaceship-prompt/spaceship-prompt.git \
        "$SPACESHIP_DIR"
fi

# ------------------------------------------------------------
# Backup
# ------------------------------------------------------------

create_backup_dir() {
    if [[ -n "$BACKUP_DIR" ]]; then
        return
    fi

    local timestamp
    timestamp="$(date '+%Y%m%d-%H%M%S')"

    BACKUP_DIR="$BACKUP_ROOT/$timestamp"

    mkdir -p "$BACKUP_DIR"

    log "Backup créé dans : $BACKUP_DIR"
}

backup_path_for() {
    local target="$1"
    local relative_path

    relative_path="${target#"$HOME"/}"

    printf '%s/%s\n' "$BACKUP_DIR" "$relative_path"
}

backup_if_needed() {
    local target="$1"
    local expected_source="$2"

    # Rien n'existe.
    if [[ ! -e "$target" && ! -L "$target" ]]; then
        log "Absent, Stow va le créer : $target"
        return
    fi

    # --------------------------------------------------------
    # Symlink
    # --------------------------------------------------------

    if [[ -L "$target" ]]; then
        local current_source

        current_source="$(readlink -f "$target")"
        expected_source="$(readlink -f "$expected_source")"

        if [[ "$current_source" == "$expected_source" ]]; then
            log "Symlink déjà correct : $target"
            return
        fi

        warn "Symlink existant mais incorrect : $target"
        warn "  actuel  : $current_source"
        warn "  attendu : $expected_source"

        create_backup_dir

        local backup_path
        backup_path="$(backup_path_for "$target")"

        mkdir -p "$(dirname "$backup_path")"

        log "Backup du symlink : $target -> $backup_path"

        mv -- "$target" "$backup_path"
        return
    fi

    # --------------------------------------------------------
    # Fichier ou répertoire normal
    # --------------------------------------------------------

    create_backup_dir

    local backup_path
    backup_path="$(backup_path_for "$target")"

    mkdir -p "$(dirname "$backup_path")"

    log "Backup : $target -> $backup_path"

    mv -- "$target" "$backup_path"
}

# ------------------------------------------------------------
# Migration des dotfiles
# ------------------------------------------------------------

migrate_dotfiles() {
    log "Vérification des configurations existantes..."

    # Zsh
    backup_if_needed \
        "$HOME/.zshrc" \
        "$DOTFILES_DIR/zsh/dot-zshrc"

    backup_if_needed \
        "$HOME/.zshrc.perso" \
        "$DOTFILES_DIR/zsh/dot-zshrc.perso"

    backup_if_needed \
        "$HOME/.zsh/spaceship.zsh" \
        "$DOTFILES_DIR/zsh/dot-zsh/spaceship.zsh"

    # Zellij
    backup_if_needed \
        "$HOME/.config/zellij/config.kdl" \
        "$DOTFILES_DIR/zellij/dot-config/zellij/config.kdl"

    backup_if_needed \
        "$HOME/.config/zellij/layouts/default.kdl" \
        "$DOTFILES_DIR/zellij/dot-config/zellij/layouts/default.kdl"

    backup_if_needed \
        "$HOME/.config/zellij/plugins/monocle.wasm" \
        "$DOTFILES_DIR/zellij/dot-config/zellij/plugins/monocle.wasm"
}

migrate_dotfiles

# ------------------------------------------------------------
# Dotfiles avec GNU Stow
# ------------------------------------------------------------

log "Installation des dotfiles avec Stow..."

cd "$DOTFILES_DIR"

stow \
    --dotfiles \
    --restow \
    --target="$HOME" \
    zsh \
    zellij

# ------------------------------------------------------------
# Installation des outils Cargo
# ------------------------------------------------------------

install_cargo_package() {
    local package="$1"
    local command="${2:-$1}"

    if command -v "$command" >/dev/null 2>&1; then
        log "$package déjà installé."
        return
    fi

    log "Installation de $package..."

    cargo install --locked "$package"
}

#install_cargo_package zellij
#install_cargo_package bat
#install_cargo_package bottom
#install_cargo_package diskus
#install_cargo_package procs

# cargo-update installe la commande `cargo-install-update`
if ! command -v cargo-install-update >/dev/null 2>&1; then
    log "Installation de cargo-update..."

    cargo install --locked cargo-update
else
    log "cargo-update déjà installé."
fi

# ------------------------------------------------------------
# Résumé
# ------------------------------------------------------------

if [[ -n "$BACKUP_DIR" ]]; then
    log "Anciennes configurations sauvegardées dans :"
    log "  $BACKUP_DIR"
else
    log "Aucun backup nécessaire."
fi

log "Installation terminée avec succès."