#!/bin/bash

#######################################################################
# Default settings
#######################################################################
# Use git by default
BUNDLE_TRANSPORT="git"

#######################################################################
# Helper functions
#######################################################################

# Make a folder (throw errors if it's already there but not a folder)
mkfolder()
{
    if [[ -e $1 ]]
    then
        if [[ ! -d $1 ]]
        then
            echo "$1 is not a directory!"
            echo "Backing up $1 to $1.bak"
            mv -v $1 $1.bak

            mkdir -p $1
        fi
    else
        mkdir -p $1
    fi
}

# Symlink file to destination folder
lnfile()
{
    # See if we are linking to a directory
    if [[ $2 =~ /$ ]]
    then
        FILE_PATH=$2
        FILE_NAME=$(basename $1)
        DST_FILE="${FILE_PATH}${FILE_NAME}"
    else
        FILE_PATH=$(dirname $2)
        FILE_NAME=$(basename $2)
        DST_FILE="$FILE_PATH/$FILE_NAME"
    fi
    SRC_FILE="$DF_PATH/$1"
    WRITE_LINK=0

    # See if the target exists
    if [[ -e $DST_FILE ]]
    then
        # Is the target a symbolic link?
        if [[ -L $DST_FILE ]]
        then
            POINTS_TO=$(readlink $DST_FILE)
            # Does it point to our file?
            if [[ "$POINTS_TO" != "$SRC_FILE" ]]
            then
                echo "Target $DST_FILE points to a different file - $POINTS_TO"
                echo -n "Replace link to point to $SRC_FILE? [y/n] "
                read -n1
                echo

                if [[ $REPLY == y || $REPLY == Y ]]
                then
                    WRITE_LINK=1
                    # Remove the old symbolic link
                    rm -f $DST_FILE
                fi
            #else
                # It already points to our file. No point in rewriting it.
            fi
        else
            # No, it's not a symbolic link
            echo "Target $DST_FILE is not a symbolic link!"
            echo "Backing up to $DST_FILE.bak"
            mv -v $DST_FILE ${DST_FILE}.bak
            WRITE_LINK=1
        fi
    else
        WRITE_LINK=1
    fi

    if [[ ! -z $DEBUG ]]
    then
        echo -n "Linking "
        [[ ! -z $WRITE_LINK ]] && echo -n "(NOT) "
        echo "'$DST_FILE' -> '$SRC_FILE'"
    fi

    if [[ $WRITE_LINK == 1 ]]
    then
        echo "Installing $1"
        ln -sf "$SRC_FILE" "$DST_FILE"
    fi
}

# Install/update vim bundles
vim_update_bundle()
{
    BUNDLE=$(echo $1 | sed 's:^.*/::' | sed 's:\.git$::')
    # If the bundle already exists, update it (if possible)
    if [[ -d "$HOME/.vim/bundle/$BUNDLE" ]]
    then
        # Don't update the bundle if BUNDLE_NO_UPDATE is set
        if [[ -d "$HOME/.vim/bundle/$BUNDLE/.git" ]]
        then
            if [[ -z $BUNDLE_NO_UPDATE ]]; then
                echo "Updating bundle $BUNDLE..."
                pushd "$HOME/.vim/bundle/$BUNDLE" >/dev/null
                git pull
                popd >/dev/null
                echo
            fi
        else
            echo "$BUNDLE is not a Git repository. Skipping update."
        fi
    else
        echo "Installing bundle $BUNDLE..."
        pushd "$HOME/.vim/bundle/" >/dev/null
        git clone $1
        popd >/dev/null
        echo
    fi
}

# Wrapper to vim_update_bundle
# Let's you specify the bundle repo in a short form if it resides on GitHub
# (and perhaps one of the repos in vim-scripts). You can still specify a full
# URL if necessary. However, that will not allow you to dynamically choose a
# transport layer at runtime
Bundle()
{
    # Get the prefix ready
    if [[ "$BUNDLE_TRANSPORT" == "ssh" ]]; then
        # If the user specifies to use ssh as the transport
        URL="git@github.com:"
    elif [[ "$BUNDLE_TRANSPORT" == "https" ]]; then
        # Use https as the transport
        URL="https://github.com/"
    elif [[ "$BUNDLE_TRANSPORT" == "git" ]]; then
        # Use git as the transport
        URL="git://github.com/"
    else
        echo "Invalid transport layer! Aborting!!!"
        exit 1
    fi

    # Check the bundle format
    if [[ $(echo $1 | grep "^[A-Za-z0-9-]\+\/[A-Za-z0-9._-]\+$") == $1 ]]; then
        # Username/repo combo
        URL="${URL}${1}.git"
    elif [[ $(echo $1 | grep "^[A-Za-z0-9._-]\+$") == $1 ]]; then
        # Bare repo name - must be from the vim-scripts user
        URL="${URL}vim-scripts/${1}.git"
    else
        # I don't care, I'm specifying the URL directly
        URL=$1
    fi

    vim_update_bundle "$URL"
}

#######################################################################
# Verify command line switches
#######################################################################
while getopts "nht:" OPTION
do
    case "$OPTION" in
        n)
            echo "Skipping bundle updates"
            BUNDLE_NO_UPDATE=1
            ;;

        t)
            echo "Using transport $OPTARG"
            BUNDLE_TRANSPORT=$OPTARG
            ;;

        h)
            echo '
This script installs the dotfiles into various locations using symbolic
links.

Options:
--------
    -n              Will not update existing bundles, but will install new
                    bundles.

    -t<option>      Specify the transport for downloading bundles. Can be
                    one of git, https or ssh. ssh transport requires you to
                    have set up the necessary keys at GitHub

    -h              Displays this help message
'
            exit 0
            ;;

        \?)
            exit 1
            break
            ;;
    esac
done

#######################################################################
# Install dotfiles
#######################################################################

# Install scripts/config files to corresponding destination folders
cd $(dirname $0)
DF_PATH=$(pwd)
PRINT_PATH=$(echo $DF_PATH | sed "s:^$HOME:~:")
echo Installing dotfiles from $PRINT_PATH

#######################################################################
# Install scripts
#######################################################################

# Create ~/bin folder
mkfolder ~/bin

# Install scripts
lnfile scripts/beep ~/bin/
lnfile scripts/stardate ~/bin/
lnfile scripts/settitle ~/bin/
lnfile scripts/smartwd ~/bin/

# Don't bother installing the note script on a Mac, it doesn't work that well
if [[ "$(uname)" != *"Darwin"* ]]
then
    lnfile scripts/note ~/bin/
    lnfile scripts/note ~/bin/n
fi

#######################################################################
# Install git configuration
#######################################################################
if [[ ! -e ~/.gitconfig ]]
then
    echo "Installing gitconfig"
    cp -v gitconfig ~/.gitconfig
    echo -n "What is your default Git username? "
    read $GIT_USER
    echo -n "What is your default Git e-mail address? "
    read $GIT_EMAIL
    git config --global user.name $GIT_USER
    git config --global user.email $GIT_EMAIL
fi

# Install git prompt functions
if [[ ! -e ~/.git_prompt.sh ]]
then
    echo "Installing Git prompt functionality..."
    curl -Sso ~/.git_prompt.sh \
    https://raw.github.com/git/git/master/contrib/completion/git-prompt.sh
fi

#######################################################################
# Install vimrc & plugins
#######################################################################

# Create VIM folders
mkfolder ~/.vim
mkfolder ~/.vim/autoload
mkfolder ~/.vim/bundle
mkfolder ~/.vim/colors
mkfolder ~/.vim/ftdetect
mkfolder ~/.vim/ftplugin
mkfolder ~/.vim/plugin
mkfolder ~/.vim/syntax

# Install vim files
lnfile vimrc ~/.vimrc

# Install my plugins
lnfile vim/plugin/long-lines.vim        ~/.vim/plugin/
lnfile vim/plugin/match-brackets.vim    ~/.vim/plugin/
lnfile vim/plugin/airline-settings.vim  ~/.vim/plugin/

# Install my ftdetect plugins
lnfile vim/ftdetect/swig.vim            ~/.vim/ftdetect/
lnfile vim/ftdetect/markdown.vim        ~/.vim/ftdetect/

# Install my filetype plugins
lnfile vim/ftplugin/make.vim            ~/.vim/ftplugin/
lnfile vim/ftplugin/perl.vim            ~/.vim/ftplugin/
lnfile vim/ftplugin/ruby.vim            ~/.vim/ftplugin/
lnfile vim/ftplugin/changelog.vim       ~/.vim/ftplugin/
lnfile vim/ftplugin/markdown.vim        ~/.vim/ftplugin/

#######################################################################
# Install/update Vim bundles
#######################################################################
Bundle  tpope/vim-pathogen                  # pathogen
Bundle  tpope/vim-fugitive                  # A Git wrapper so awesome, it
                                            # should be illegal!
Bundle  zaiste/tmux.vim                     # tmux config file syntax
Bundle  altercation/vim-colors-solarized    # Solarized
Bundle  vimwiki                             # Vimwiki
Bundle  msanders/snipmate.vim               # snipMate
Bundle  tomtom/tcomment_vim                 # tComment
Bundle  bling/vim-airline                   # Airline is awesome!

#######################################################################
# Install tmux & screen config files
#######################################################################

# Install tmux configuration file
lnfile tmux.conf ~/.tmux.conf

# Install screen configuration file
lnfile screenrc ~/.screenrc

#######################################################################
# Install bashrc files
#######################################################################
if [[ -L ~/.bashrc.common ]]
then
    PRINT_INST=0
else
    PRINT_INST=1
fi

lnfile bash/bashrc.common ~/.bashrc.common
lnfile bash/bashrc.lscolors ~/.bashrc.lscolors
lnfile bash/bashrc.aliases ~/.bashrc.aliases
lnfile dircolors ~/.dir_colors

if [[ $PRINT_INST == 1 ]]
then
    echo "Add the following line to your ~/.bashrc file"
    echo "    source ~/.bashrc.common"
fi