setup.sh

#!/bin/sh
SCRIPT_PATH=$(cd $(dirname $0) && pwd -P)

#######################################
# Resolve canonicalized path of a given target.
#
# Arguments:
#   Path to be canonicalized.
# Outputs:
#   Set the result to a variable `CANONICALIZED`
#######################################
canonicalize() {
    _COUNT=100
    _DIRNAME=$(dirname $1)
    _BASENAME=$(basename $1)

    while test -L "$_DIRNAME/$_BASENAME"; do
        _TARGET=$(readlink "$_DIRNAME/$_BASENAME")
        _DIRNAME=$(dirname "$_TARGET")
        _BASENAME=$(basename "$_TARGET")

        if test $_COUNT -le 0; then
            echo "error: too many recursion" >&2
            return 1
        fi
        _COUNT=$(expr $_COUNT + 1)
    done

    CANONICALIZED=$(cd $_DIRNAME && pwd -P)/$_BASENAME
    unset _DIRNAME _BASENAME
}

#######################################
# Make a symbolic link file $1 which points to $2.
#
# Arguments:
#   1. Path of a symbolic link to create.
#   2. Symbolic link target.
# Outputs:
#   (stderr) Error message if failed
# Returns:
#   1 if any error detected otherwise 0
#######################################
makelink() {
    # Resolve canonicalized path of the target file
    canonicalize $2
    if test $? -ne 0; then
         echo "error: failed to resolve canonicalized path of $2" >&2
         return 1
    fi

    # Make a link unless the target is a symlink to the source
    if test "$CANONICALIZED" != "$1"; then
        ln -fsv "$1" "$2"
        if test $? -ne 0; then
            echo "error: failed to create a link \"$2\"" >&2
            return 1
        fi
        unset CANONICALIZED
    fi
    return 0
}

#######################################
# Insert a line ($1) to a file ($2) if it's not inserted.
#
# Arguments:
#   1. String to insert.
#   2. Path of a file to which the line is inserted.
# Outputs:
#   (stdout) Trace message.
#######################################
insert_line() {
    # Ensure that the target file exists
    if test ! -e $2; then
        mkdir -pv $(dirname $2)
        touch $2
    fi

    # Insert a line to "source" the target file if not inserted yet
    if test $(grep "$1" $2 | wc -l 2>/dev/null) = 0; then
        echo "Inserting \"$1\" into \"$2\""
        echo "$1" >>$2
    fi
}

#######################################
# Insert code block to "source" a file ($1) to a file ($2) if it's not inserted yet.
#
# Arguments:
#   1. Path of a file to be "source"d.
#   2. Path of a file to which the code block is inserted.
# Outputs:
#   (stdout) Trace message.
#######################################
insert_source_line() {
    # Ensure that the target file exists
    if test ! -e $2; then
        mkdir -pv $(dirname $2)
        touch $2
    fi

    # Insert a line to "source" the target file
    if test $(grep \"$1\" $2 | wc -l 2>/dev/null) = 0; then
        echo "Modifying \"$2\" to source \"$1\""
        echo "if test -r \"$1\"; then" >>$2
        echo "    source \"$1\"" >>$2
        echo "fi" >>$2
    fi
}

# Profile
[ -e ~/.bashrc ] &&         insert_source_line $SCRIPT_PATH/profile/rc.sh       ~/.bashrc
[ -e ~/.zshrc ] &&          insert_source_line $SCRIPT_PATH/profile/rc.sh       ~/.zshrc
[ -e ~/.profile ] &&        insert_source_line $SCRIPT_PATH/profile/profile.sh  ~/.profile
[ -e ~/.bash_profile ] &&   insert_source_line $SCRIPT_PATH/profile/profile.sh  ~/.bash_profile
[ -e ~/.zprofile ] &&       insert_source_line $SCRIPT_PATH/profile/profile.sh  ~/.zprofile
insert_line "set editing-mode emacs"                ~/.inputrc
makelink $SCRIPT_PATH/tmux.conf                     ~/.tmux.conf

# Nushell
insert_line "source $SCRIPT_PATH/nu/env.nu" ~/.config/nushell/env.nu
insert_line "source $SCRIPT_PATH/nu/config.nu" ~/.config/nushell/config.nu

# Git
if command -v git >/dev/null; then
    mkdir -pv ~/.config/git
    makelink $SCRIPT_PATH/git/ignore ~/.config/git/ignore
    already_sourced=no
    for path in $(git config --global --get-all include.path); do
        if test $path -ef $SCRIPT_PATH/git/config; then
            already_sourced=yes
        fi
    done
    if test $already_sourced = "no"; then
        git config --global --add include.path $SCRIPT_PATH/git/config
        echo "Updated 'include.path' of Git config as:"
        git config --global --get-all include.path
    fi
fi

# VIM
mkdir -pv ~/.vim/autoload ~/.vim/colors
makelink $SCRIPT_PATH/vimfiles/vimrc                ~/.vim/vimrc
makelink $SCRIPT_PATH/vimfiles/common.vim           ~/.vim/common.vim
makelink $SCRIPT_PATH/vimfiles/keymaps.vim          ~/.vim/keymaps.vim
makelink $SCRIPT_PATH/vimfiles/regular.vim          ~/.vim/regular.vim
makelink $SCRIPT_PATH/vimfiles/autoload/plug.vim    ~/.vim/autoload/plug.vim

# Neovim
mkdir -pv ~/.config/nvim/autoload
mkdir -pv ~/.config/nvim/lua/plugins
makelink $SCRIPT_PATH/nvim/init.lua                 ~/.config/nvim/init.lua
makelink $SCRIPT_PATH/nvim/lua/keymaps.lua          ~/.config/nvim/lua/keymaps.lua
makelink $SCRIPT_PATH/vimfiles/autoload/plug.vim    ~/.config/nvim/autoload/plug.vim
for f in $SCRIPT_PATH/nvim/lua/plugins/*; do
    if [ -f "$f" ]; then
        basename=$(basename $f)
        makelink "$f" ~/.config/nvim/lua/plugins/$basename
    fi
done

# Remove dead symlinks
for link in $(find ~/.config/nvim -type l); do
    if [ ! -e $link ]; then
        echo "rm -f $link # dead link"
        rm -f $link
    fi
done