#! /bin/bash

#####################################################################
#	     ___        __   ___                   __
#	  __| _/ ____ _/  |_ \_ |__ _____    ____ |  | ____ ________
#	 / __ | / __ \\   __\ | __ \\__  \ _/ ___\|  |/ /  |  \____ \
#	/ /_/ |(  \_\ )|  |   | \_\ \/ __ \_  \___|    \|  |  /  |_\ \
#	\____ | \____/ |__|   |___  /____  /\___  /__|_ \____/|   ___/
#	     \/                   \/     \/     \/     \/     |__|
#
#	by danix
#
#####################################################################

set -euo pipefail

# Colors for output
GREEN='\033[0;32m'
BLUE='\033[0;34m'
YELLOW='\033[1;33m'
RED='\033[0;31m'
NC='\033[0m' # No Color

### DIRECTORIES
WORKDIR=$(pwd)

# Defaults (can be overridden by config file)
DEFAULT_OUTPUT_DIR="${HOME}/Programming/GIT/my-dotfiles"
LOG_FILE="${HOME}/.local/share/dot-backup/backup.log"
DOTFILES_LIST="${HOME}/.config/dot-backup/files.list"
CONFIG_FILE="${HOME}/.config/dot-backup/config"
GIT_REMOTE=""
GIT_BRANCH=""

# Bootstrap config and log directories on first run
FIRST_RUN=false
if [[ ! -d "$(dirname "$CONFIG_FILE")" ]]; then
    FIRST_RUN=true
fi
mkdir -p "$(dirname "$CONFIG_FILE")"
mkdir -p "$(dirname "$LOG_FILE")"

# Load config file if present
if [[ -f "$CONFIG_FILE" ]]; then
    # shellcheck source=/dev/null
    source "$CONFIG_FILE"
fi

# Flags
DRY_RUN=false
VERBOSE=false
RESTORE=false
QUIET=false
PUSH=false

usage() {
    echo "Usage: $0 [options]"
    echo "  -n, --dry-run    Show what would be copied without copying"
    echo "  -v, --verbose    Print each file as it is processed"
    echo "  -r, --restore    Restore dotfiles from backup to their original locations"
    echo "  -q, --quiet      Suppress stdout; write output to log instead"
    echo "  -p, --push       Push to remote after commit (requires GIT_REMOTE in config)"
    echo "  -h, --help       Show this help"
    exit 0
}

for arg in "$@"; do
    case $arg in
        -n|--dry-run) DRY_RUN=true ;;
        -v|--verbose) VERBOSE=true ;;
        -r|--restore) RESTORE=true ;;
        -q|--quiet) QUIET=true ;;
        -p|--push) PUSH=true ;;
        -h|--help) usage ;;
        *) echo -e "${RED}Unknown option: $arg${NC}"; usage ;;
    esac
done

if [[ "$QUIET" == true ]]; then
    # save original stdout so we can notify user after redirect
    exec 3>&1
    # strip color codes and write to log
    exec > >(sed 's/\x1b\[[0-9;]*m//g' > "$LOG_FILE") 2>&1
fi

# The list of dotfiles
DOTFILES=(
    # Shell configurations
    ".bashrc"
    ".bash_profile"
    ".bash_aliases"
    ".bash_functions"
    ".dir_colors"
    ".lessfilter"
    ".profile.d"

    # Shell history (optional - comment out if you don't want history)
    # ".bash_history"

    # Git configuration
    ".gitconfig"
    ".gitignore_global"
    ".gitmessage"

    # Desktop
    ".fonts"
    ".icons"
    ".local/share/applications"
    ".local/share/icons"
    ".user-icon.jpg"

    # Editors
    ".config/nvim"
    ".config/sublime-text"

    # hyprland
    ".config/hypr"
    ".config/wal"
    ".config/waybar"
    ".config/qarma.conf"

    # firefox
    # ".mozilla"

    # thunderbird
    # ".thunderbird"

    # music players
    ".config/mpd"
    ".config/rmpc"
    ".config/sayonara"
    ".config/haruna"
    ".config/harunarc"

    # other programs
    ".config/bash-notes.rc"
    ".config/cherrytree"
    ".config/conky"
    ".config/draw.io"
    ".config/featherpad"
    ".config/htop"
    ".config/joplin-desktop"
    ".config/kitty"
    ".config/lximage-qt"
    ".config/lxqt"
    ".config/mimeapps.list"
    ".config/pcmanfm-qt"
    ".config/powerline"
    ".config/qpdfview"
    ".config/rofi"

    # pandoc
    ".local/share/pandoc/"

    # my executables
    "bin"

    ### SYSTEM FILES
    # bash completion
    "/etc/bash_completion.d"
)

# Load external list if it exists, appending to built-in list
if [[ -f "$DOTFILES_LIST" ]]; then
    while IFS= read -r line || [[ -n "$line" ]]; do
        [[ "$line" =~ ^#.*$ || -z "$line" ]] && continue
        DOTFILES+=("$line")
    done < "$DOTFILES_LIST"
fi

# helper function to check if a string ($2) begins with another string ($1)
beginswith() { [[ "$2" == "$1"* ]]; }

lastupdate() {
    D=$(date)
    echo "Last update: $D" > "${DEFAULT_OUTPUT_DIR}/lastupdate"
}

log_verbose() {
    [[ "$VERBOSE" == true ]] && echo -e "$1" || true
}

do_rsync() {
    local src="$1"
    local dst="$2"
    local is_dir="${3:-false}"
    if [[ "$DRY_RUN" == true ]]; then
        echo -e "\t ${YELLOW}[dry-run] would copy: $src → $dst${NC}"
    else
        if [[ "$is_dir" == true ]]; then
            mkdir -p "$dst"
            if [[ "$VERBOSE" == true ]]; then
                rsync -av "$src/" "$dst/"
            else
                rsync -a "$src/" "$dst/" && echo -e "\t ${GREEN}Copied${NC}"
            fi
        else
            if [[ "$VERBOSE" == true ]]; then
                rsync -av "$src" "$dst"
            else
                rsync -a "$src" "$dst" && echo -e "\t ${GREEN}Copied${NC}"
            fi
        fi
    fi
}

# ── RESTORE MODE ──────────────────────────────────────────────────────────────

do_restore() {
    if [[ ! -d "$DEFAULT_OUTPUT_DIR" ]]; then
        echo -e "${RED}Backup directory not found: $DEFAULT_OUTPUT_DIR${NC}"
        exit 1
    fi

    echo -e "${YELLOW}Restoring dotfiles from: ${BLUE}$DEFAULT_OUTPUT_DIR${NC}\n"

    local system_skipped=0

    for i in "${DOTFILES[@]}"; do
        if beginswith "/" "$i"; then
            # system file — requires root
            local backup_path="${DEFAULT_OUTPUT_DIR}/system/${i#/}"
            local dest="$i"
            if [[ "$EUID" -ne 0 ]]; then
                if [[ -e "$backup_path" ]]; then
                    if [[ "$DRY_RUN" == true ]]; then
                        echo -e "${YELLOW}$dest${NC}"
                        echo -e "\t ${YELLOW}[dry-run] would restore: $backup_path → $dest (needs root)${NC}"
                    else
                        echo -e "${YELLOW}SKIP (needs root): $dest${NC}"
                        (( system_skipped++ )) || true
                    fi
                else
                    log_verbose "\t ${YELLOW}SKIP (not in backup): $i${NC}"
                fi
                continue
            fi
        else
            local backup_path="${DEFAULT_OUTPUT_DIR}/home/$i"
            local dest="${HOME}/$i"
        fi

        if [[ -f "$backup_path" ]]; then
            echo -e "${GREEN}$dest${NC}"
            if [[ "$DRY_RUN" == true ]]; then
                echo -e "\t ${YELLOW}[dry-run] would restore: $backup_path → $dest${NC}"
            else
                mkdir -p "$(dirname "$dest")"
                if [[ "$VERBOSE" == true ]]; then
                    rsync -av "$backup_path" "$dest"
                else
                    rsync -a "$backup_path" "$dest" && echo -e "\t ${GREEN}Restored${NC}"
                fi
            fi
        elif [[ -d "$backup_path" ]]; then
            echo -e "${BLUE}$dest${NC}"
            if [[ "$DRY_RUN" == true ]]; then
                echo -e "\t ${YELLOW}[dry-run] would restore: $backup_path/ → $dest/${NC}"
            else
                mkdir -p "$dest"
                if [[ "$VERBOSE" == true ]]; then
                    rsync -av "$backup_path/" "$dest/"
                else
                    rsync -a "$backup_path/" "$dest/" && echo -e "\t ${GREEN}Restored${NC}"
                fi
            fi
        else
            log_verbose "\t ${YELLOW}SKIP (not in backup): $i${NC}"
        fi
    done

    if [[ "$system_skipped" -gt 0 ]]; then
        echo -e "\n${YELLOW}Warning: $system_skipped system file(s) skipped — re-run as root to restore them.${NC}"
    fi

    if [[ "$DRY_RUN" == true ]]; then
        echo -e "\n${YELLOW}Dry run complete. Nothing restored.${NC}"
    else
        echo -e "\n${GREEN}Restore complete.${NC}"
    fi
    if [[ "$QUIET" == true ]]; then echo "Log written to: $LOG_FILE" >&3; fi
    exit 0
}

# ── MAIN ──────────────────────────────────────────────────────────────────────

if [[ "$QUIET" == false && -t 1 ]]; then clear; fi

if [[ "$FIRST_RUN" == true ]]; then
    echo -e "${GREEN}First run — config directories created:${NC}"
    echo -e "  ${BLUE}$(dirname "$CONFIG_FILE")${NC}  — drop config and files.list here"
    echo -e "  ${BLUE}$(dirname "$LOG_FILE")${NC}  — logs written here when using -q"
    echo -e "\nOptional next steps:"
    echo -e "  cp config.example ${CONFIG_FILE}"
    echo -e "  touch ${DOTFILES_LIST}"
    echo -e "\nRun again to start backing up.\n"
    exit 0
fi

if [[ "$DRY_RUN" == true ]]; then
    echo -e "${YELLOW}*** DRY RUN — no files will be copied ***${NC}\n"
fi

if [[ "$RESTORE" == true ]]; then
    do_restore
fi

echo -e "${YELLOW}Local Git Repository: ${NC}"
if [[ -d "$DEFAULT_OUTPUT_DIR" ]]; then
    echo -e "\t${BLUE}$DEFAULT_OUTPUT_DIR ${GREEN} ${NC}"
    [ -d "$DEFAULT_OUTPUT_DIR/home" ] || mkdir -p "$DEFAULT_OUTPUT_DIR/home"
    [ -d "$DEFAULT_OUTPUT_DIR/system" ] || mkdir -p "$DEFAULT_OUTPUT_DIR/system"
    cd "$DEFAULT_OUTPUT_DIR" || { echo -e "${RED}Cannot cd to $DEFAULT_OUTPUT_DIR${NC}"; exit 1; }
    if git rev-parse --is-inside-work-tree &>/dev/null; then
        echo -e "${GREEN}Git Repository already initialized.${NC}"
    else
        echo -e "${YELLOW}Initializing Git Repository.${NC}"
        git init
        git add .
    fi
else
    echo -e "\t${BLUE}$DEFAULT_OUTPUT_DIR ${RED} ${NC}"
    if [[ "$DRY_RUN" == false ]]; then
        echo -e "${YELLOW}creating our backup directories${NC}"
        mkdir -p "$DEFAULT_OUTPUT_DIR"/{home,system}
        echo -e "${YELLOW}Initializing Git Repository.${NC}"
        cd "$DEFAULT_OUTPUT_DIR" || { echo -e "${RED}Cannot cd to $DEFAULT_OUTPUT_DIR${NC}"; exit 1; }
        git init
        git add .
    fi
fi

# Ensure remote is registered if GIT_REMOTE is configured
if [[ -n "$GIT_REMOTE" && "$DRY_RUN" == false ]]; then
    cd "$DEFAULT_OUTPUT_DIR" || { echo -e "${RED}Cannot cd to $DEFAULT_OUTPUT_DIR${NC}"; exit 1; }
    if git remote get-url origin &>/dev/null; then
        current=$(git remote get-url origin)
        if [[ "$current" != "$GIT_REMOTE" ]]; then
            echo -e "${YELLOW}Updating remote origin: $GIT_REMOTE${NC}"
            git remote set-url origin "$GIT_REMOTE"
        fi
    else
        echo -e "${YELLOW}Adding remote origin: $GIT_REMOTE${NC}"
        git remote add origin "$GIT_REMOTE"
    fi
    cd "$WORKDIR"
fi

if [[ "$DRY_RUN" == false ]]; then
    lastupdate
fi
echo -e "$NC"

# we iterate all dotfiles in the list
for i in "${DOTFILES[@]}"; do
    # if it's a file in my home
    if [[ -f "${HOME}/$i" ]]; then
        echo -e "${GREEN}${HOME}/$i${NC}"
        do_rsync "${HOME}/$i" "${DEFAULT_OUTPUT_DIR}/home/$i"
    # if it's a directory in my home
    elif [[ -d "${HOME}/$i" ]]; then
        echo -e "${BLUE}${HOME}/$i${NC}"
        do_rsync "${HOME}/$i" "${DEFAULT_OUTPUT_DIR}/home/$i" true
    # if it begins with a / it's a system file/directory
    elif beginswith "/" "$i"; then
        if [[ -f "$i" ]]; then
            echo -e "${GREEN}$i${NC}"
            do_rsync "$i" "${DEFAULT_OUTPUT_DIR}/system/${i#/}"
        elif [[ -d "$i" ]]; then
            echo -e "${BLUE}$i${NC}"
            do_rsync "$i" "${DEFAULT_OUTPUT_DIR}/system/${i#/}" true
        else
            echo -e "\n${RED}NOT FOUND: ${i}${NC}\n"
        fi
    else
        echo -e "\n${RED}NOT FOUND: ${i}${NC}\n"
    fi
done

if [[ "$DRY_RUN" == true ]]; then
    echo -e "\n${YELLOW}Dry run complete. No files copied, no git changes made.${NC}"
    exit 0
fi

echo -e "\n${GREEN}Adding all copied files to git.${NC}"
cd "$DEFAULT_OUTPUT_DIR" || { echo -e "${RED}Cannot cd to $DEFAULT_OUTPUT_DIR${NC}"; exit 1; }
git add .

if git diff --cached --quiet; then
    echo -e "${YELLOW}Nothing new to commit.${NC}"
else
    if ! git commit -m "backup: $(date '+%Y-%m-%d %H:%M:%S')"; then
        echo -e "${RED}Commit failed (hook rejected?). Files staged but not committed.${NC}"
        exit 1
    fi
    echo -e "${GREEN}Committed.${NC}"
fi

if [[ "$PUSH" == true ]]; then
    if ! git remote get-url origin &>/dev/null; then
        echo -e "${RED}--push requested but no remote configured. Set GIT_REMOTE in config.${NC}"
        exit 1
    fi
    branch="${GIT_BRANCH:-$(git symbolic-ref --short HEAD)}"
    echo -e "${GREEN}Pushing to origin/$branch...${NC}"
    if ! git push origin "$branch"; then
        echo -e "${RED}Push failed.${NC}"
        exit 1
    fi
    echo -e "${GREEN}Pushed.${NC}"
fi

echo -e "$NC"
cd "$WORKDIR"
if [[ "$QUIET" == true ]]; then echo "Log written to: $LOG_FILE" >&3; fi
exit 0