#!/bin/zsh
# .files/install
# (c) 2014-2021 MORI Taeyeon

# Paths & Utils
DOT="$(realpath "$(dirname "$0")")"
cd "$DOT"

setopt EXTENDED_GLOB
source "$DOT/lib/libzsh-utils.zsh"


# Parse commandline
# =============================
OVERWRITE=false
ASK=true
INSTALL_ZSH=true
INSTALL_DOT=true
INSTALL_CNF=true
INSTALL_GIT=true
INSTALL_CHSH=true
INSTALL_EXTRA=true

function print_usage() {
    echo "Usage: $1 [--help] [--overwrite] [--dont-ask]"
    echo
    echo "Install Tae's dotfiles"
    echo
    echo "Parameters:"
    echo "    -h, --help    Display this help message"
    echo "    --overwrite   Just overwrite existing dotfiles"
    echo "    --dont-ask    Don't ask questions. Use default values"
    echo "    --no-{zsh,dotfiles,config,git,chsh,extra}"
    echo "                  Don't set up the specific component"
}

for arg in "$@"; do
    [[ -z "$STATE" ]] && {
        case "$arg" in
            -h|--help) print_usage "$0"; exit 0;;
            --overwrite) OVERWRITE=true;;
            --dont-ask) ASK=false;;
            --no-zsh) INSTALL_ZSH=false;;
            --no-dotfiles) INSTALL_DOT=false;;
            --no-config) INSTALL_CNF=false;;
            --no-git) INSTALL_GIT=false;;
            --no-chsh) INSTALL_CHSH=false;;
            --no-extra) INSTALL_EXTRA=false;;
            *) print_usage "$0"; exit 1;;
        esac
    } || {
        case "$STATE" in
            # handle options with parameters
        esac
        STATE=
    }
done
[[ -n "$STATE" ]] && err "Option $STATE is missing it's parameter!" && exit 1


# Helper functions
# =============================
function generate() {
    [[ -e "$1" ]] && ! $OVERWRITE && ! grep -q "Generated by .files/install" "$1" && \
        err "Custom version of $1 detected. Please delete it before running .files/install" && exit 1
    echo "${2-#} Generated by .files/install" >"$1"
    echo "${2-#} `date "+%m/%d/%Y %H:%M:%S"`" >>"$1"
    echo >>"$1"
    cat >>"$1"
}

function relink() {
    [[ ! -e "$1" ]] && err "No such file or directory: '$1'" && return 1
    [[ -L "$2" ]] && rm -f "$2"
    [[ -e "$2" ]] && ! $OVERWRITE && err "File already exists and isn't a symbolic link: '$2'" && return 1
    [[ ! -d "`dirname "$2"`" ]] && mkdir -p "`dirname "$2"`"
    color 31 ln -sr "$1" "$2"
}


# Prepare
# =============================
# Update git modules
msg "Updating git submodules..."
git submodule update --init --recursive

# Ask questions about user
$ASK && msg "Asking questions..." || err "Not asking any questions:"

# Try to load previous configuration
[[ -e "$DOT/etc/user-info" ]] && source "$DOT/etc/user-info"
[[ -e "$DOT/etc/hostname" ]] && HOSTNAME=`cat "$DOT/etc/hostname"`

# Retrieve realname from /etc/passwd GECOS
[[ -z "$REALNAME" ]] && REALNAME=`grep "^$USER:[^:]*:$UID:" /etc/passwd | cut -d: -f5 | cut -d, -f1`
[[ -z "$HOSTNAME" ]] && HOSTNAME=`hostname`

if $ASK; then
    ask "  Real name" REALNAME
    ask "  E-Mail address" EMAIL
    ask "  Computer name" HOSTNAME
else
    color 36 echo "  default REALNAME=\"$REALNAME\""
    color 36 echo "  default EMAIL=\"$EMAIL\""
    color 36 echo "  default HOSTNAME=\"$HOSTNAME\""
fi

# Write down answers
color 32 echo "  Writing etc/user-info"
generate "$DOT/etc/user-info" <<EOF
REALNAME="$REALNAME"
EMAIL="$EMAIL"
EOF

color 32 echo "  Writing etc/hostname"
echo $HOSTNAME >"$DOT/etc/hostname"

# Handle local-only alternatives
HOST_LC=${(L)HOSTNAME}

function refset() {
    eval "$1=\$2"
}

function inspect_name() {
    # gimme namerefs...
    #local -n name=$1 prio=$2
    #local filename=$3
    # Check local-only files
    refset $1 ${3%.local}
    if [[ ${(P)1} != $3 ]]; then
        refset $2 3
        return 0
    fi
    # Check hostname-specific file
    refset $1 ${3%@*}
    if [[ ${(P)1} != $3 ]]; then
        refset $2 2
        [[ ${3##*@} == $HOST_LC ]]
        return $?
    fi
    # Standard file
    refset $2 1
    return 0
}

function add_names() {
    local an_name an_prio
    #local -n names=$1 prios=$2
    for an_file in ${(@)argv[3,$#]}; do
        if inspect_name an_name an_prio $an_file && [[ $an_prio -gt ${${(P)2}[$an_name]} ]]; then
            refset $1\[\$an_name\] $an_file
            refset $2\[\$an_name\] $an_prio
        fi
    done
}

# Write files to $HOME
# =============================
# Setup dotfiles
if $INSTALL_DOT; then
     msg "Linking dotfiles..."
    (){
        local -A names prios
        pushd $DOT/dotfiles
        add_names names prios *
        for name src in ${(@kv)names}; do
            color 32 echo "  Adding .$name"
            relink $src $HOME/.$name
        done
        popd
    }
else
    msg "Skipped dotfiles."
fi

# Setup .config
if $INSTALL_CNF; then
    : ${XDG_CONFIG_HOME:=~/.config}
    msg "Linking .config files... ($XDG_CONFIG_HOME)"
    (){
        function relink_r() {
            local target=$1 dest=$2 name=${3:-$2} from
            [[ ${target:t} != ${dest:t} ]] && from=" (${target:t})"
            if [[ ! -d $target ]]; then
                color 32 echo "  Adding $name$from"
                relink $target $dest
            else
                if [[ ! -d $dest ]]; then
                    color 32 echo "  Creating directory $name/$from"
                    mkdir $dest
                elif [[ -n $from ]]; then
                    color 32 echo "  Adding directory $name/$from"
                fi
                # This is still slightly ugly
                local -A names prios
                add_names names prios $target/*
                for dst src in ${(@kv)names}; do
                    relink_r $src $dest/${dst:t} $name/${dst:t}
                done
            fi
        }
        pushd $DOT/config
        local -A names prios
        add_names names prios *
        for dst src in ${(@kv)names}; do
            relink_r $src $XDG_CONFIG_HOME/$dst $dst
        done
        popd
    }
else
    msg "Skipped .config"
fi

# Setup git
# =============================
if $INSTALL_GIT; then
    msg "Setting up Git configuration..."

    GIT="$DOT/git"
    [[ -e "$HOME/.gitconfig" ]] && ! grep -q ".files/install" "$HOME/.gitconfig" && err "Custom ~/.gitconfig already exists! Please remove it before running .files/install" && exit 1

    color 32 echo "  Writing .gitconfig"
    generate "$HOME/.gitconfig" <<EOF
[include]
    path = $(relpath "$GIT" "$HOME")/config
    path = $(relpath "$GIT" "$HOME")/user-info
EOF

    [ "`uname -s`" = "Darwin" ] && \
    cat >>"$HOME/.gitconfig" <<EOF
    path = $(relpath "$GIT" "$HOME")/osx
EOF

    color 32 echo "  Writing git/user-info"
    generate "$GIT/user-info" <<EOF
[user]
    name = $REALNAME
    email = $EMAIL
EOF
else
    msg "Skipped git configuration"
fi

# Setup ZSH/Prezto
# =============================
if $INSTALL_ZSH; then
    msg "Setting up ZSH configuration..."
    ZSH="$DOT/zsh"

    color 32 echo "  Writing .zshenv"
    generate "$HOME/.zshenv" <<EOF
export DOTFILES="\$HOME/$(relpath "$DOT" "$HOME")"
ZDOTDIR="\$DOTFILES/zsh"
[[ -f "\$ZDOTDIR/zshenv" ]] && source "\$ZDOTDIR/zshenv"
[[ ! -o LOGIN && "\$SHLVL" == 1 && -f "\$ZDOTDIR/zprofile" ]] && source "\$ZDOTDIR/zprofile"
EOF

    for file in zshrc zpreztorc zlogin zlogout zprofile; do
        color 32 echo "  Adding .$file"
        relink "$ZSH/$file" "$ZSH/.$file"
    done
else
    msg "Skipped ZSH configuration."
fi


# Do misc setup
# =============================
if [ -x "$DOT/install.extra" ]; then
    if $INSTALL_EXTRA; then
        msg "Running install.extra..."
        "$DOT/install.extra"
    else
        msg "Not running install.extra."
    fi
fi

# Check login shell
if $INSTALL_CHSH; then
    if  getent passwd $(id -un) | grep -q 'zsh$'; then
        msg "Login shell is already set to zsh, you're good to go!"
    else
        msg "Setting login shell to '$(which zsh)'..."
        chsh -s "$(which zsh)"
    fi
fi

# Done.
warn "You may need to relog for all changes to take effect."
$INSTALL_ZSH && warn "If you're currently running zsh, you definitely need to at least restart the shell to apply changes."