#!/bin/bash

###########################################################
#
# Marc's environment bootstrap script.
#
# Table of contents
#
# 1. Helpers and utilities
#       These functions are used by individual bootstrap
#       steps and are reused all over.
# 2. Steps
#       Functions implementing a specific action in the
#       bootstrap process.
# 3. Bootstrap sequence and callsite
#       Where the magic happens.
#       This is where the ordered sequence of steps
#       is defined and run.
#
###########################################################

###########################################################
#
# 1. Helpers and utilities
#
###########################################################

STEP_COUNT=0
SUBSTEP_COUNT=0

# Pretty-print step headers.
pre_step() {
    STEP_COUNT=$((STEP_COUNT + 1))
    SUBSTEP_COUNT=0
    echo -e "\e[1m[$STEP_COUNT/$TOTAL_STEPS] <====== $1 =======>\e[0m"
}

# Pretty-prints substep headers.
pre_substep() {
    SUBSTEP_COUNT=$((SUBSTEP_COUNT + 1))
    echo -e "\e[1m[$STEP_COUNT.$SUBSTEP_COUNT] <====== $1 =======>\e[0m"
}

# Copies a file from $1 to $2.
#
# If $2 exists, checks if $1 == $2 and asks what to do.
# From there, the user providing "O" will overwrite (proceed with copy),
# "S" will skip the file and leave the destination as-is, and anyting else
# will skip the copy altogether (i.e. "S").
copy_file() {
    source_path=$1
    dest_path=$2

    if [ ! -e "$dest_path" ]; then
        cp "$source_path" "$dest_path"
        echo "Copied $source_path > $dest_path"
        return 0
    fi

    difference=$(diff "$source_path" "$dest_path")

    if [ -z "$difference" ]; then
        echo "$dest_path already exists, but is the same as $source_path - skipping."
        return 0
    fi

    echo "Differences detected between $source_path and $dest_path:"
    diff --color "$source_path" "$dest_path"
    read -p "$dest_path already exists. What should be done? [O:overwrite,S:skip,B:save backup and copy] " -r action

    if [[ $action == "O" ]]; then
        cp "$source_path" "$dest_path"
        echo "Overwrote $source_path > $dest_path"
        return 0
    fi

    if [[ $action == "S" ]]; then
        echo "Skipped and left $dest_path as is."
        return 0
    fi

    if [[ $action == "B" ]]; then
        cp "$dest_path" "$dest_path".old
        echo "Backed up $dest_path up to $dest_path.old"
        cp "$source_path" "$dest_path"
        echo "Overwrote $source_path > $dest_path"
        return 0
    fi

    echo "Unrecognized action, doing nothing."
}

##########################################################
#
# 2. Steps
#
##########################################################

# Ensures that all existing Apt packages are up-to-date.
ensure_apt_up_to_date() {
    pre_step "Ensuring apt packages are up-to-date" 

    if [ -z "$(apt --version 2> /dev/null)" ]; then
        echo -e "\e[33mApt not installed, skipping updates.\e[0m"
    else
        echo -e "\e[1mEnsuring system packages are up-to-date...\e[0m"
        
        sudo apt update && sudo apt upgrade -y --autoremove

        echo -e "\e[1;32mSystem packages up-to-date.\e[0m"
    fi
}

# Installs packages as specified in apt.txt
ensure_apt_dependencies() {
    pre_step "Installing extra packages"

    if [ -z "$(apt --version 2> /dev/null)" ]; then
        echo -e "\e[33mApt not installed, skipping packages.\e[0m"
    else
        echo -e "\e[1mInstalling packages...\e[0m"
        
        sudo apt install "$(cat ./files/apt.txt)" -y --autoremove

        echo -e "\e[1;32mSystem packages installed.\e[0m"
    fi
}

# Installs the rustup toolchain if not installed.
# If installed, the toolchain is updated.
install_rust() {
    pre_step "Install and configure Rust toolchain"

    if [ -z "$(rustup --version 2> /dev/null)" ]; then
        curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
    else
        rustup update
    fi
}

install_omz() {
    pre_step "Installs Oh My ZSH"
    curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh | bash
}

# Installs the Starship prompt and adds an initialization
# command to the shell configuration file.
#
# Requires: install_rust
install_and_configure_starship() {
    pre_step "Install and configure Starship"

    pre_substep "Install Starship via cargo"
    cargo install starship --locked

    pre_substep "Add initialization command to shell configuration"
    if [ -z "$(rg "starship init zsh" ~/.zshrc)" ]; then 
        printf "#Initialize Starship prompt\neval \"\$(starship init zsh)\"" >> ~/.zshrc
    fi

    pre_substep "Copy configuration in configuration directory"

    copy_file ./files/starship.toml ~/.config/starship.toml
}

install_nvm() {
    pre_step "Installing nvm to manage node version"
    
    pre_substep "Installing NVM from remote"
    curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

    pre_substep "Ensuring that NVM can be run right away"
    # Ensuring that nvm is usable right away without restarting the shell
    export NVM_DIR="$HOME/.nvm"
    # shellcheck disable=SC1091
    [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
    # shellcheck disable=SC1091
    [ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion" 
}

install_gh_plugins() {
    pre_step "Installing gh cli plugins"

    gh extension install nektos/gh-act

    gh extension install dlvhdr/gh-dash
    copy_file ./files/gh-dash_config."$ENV_PROFILE".yml ~/.config/gh-dash/config.yml

    gh extension upgrade --all
}

install_pyenv() {
    pre_step "Install and configure pyenv"

    curl https://pyenv.run | bash
}

# Injects a managed block in the shell configuration.
inject_shell_configuration() {
    pre_step "Injecting managed block in shell configuration"

    BLOCK_DELIMITER_PATTERN="mcataford/env"
    WORKING_PATH=$(git rev-parse --show-toplevel)
    SHELL_CONFIG_PATH="$HOME/.zshrc"

    echo "Setting up shell configuration extras..."
    if ! grep -q "$BLOCK_DELIMITER_PATTERN" < "$SHELL_CONFIG_PATH"; then
        printf "# %s:start\nsource %s/files/shell_extras\n# %s:end" \
            "$BLOCK_DELIMITER_PATTERN" "$WORKING_PATH" "$BLOCK_DELIMITER_PATTERN" \
            >> "$SHELL_CONFIG_PATH"
        echo "✅ Added managed block to $SHELL_CONFIG_PATH"
    else
        echo "No changes to apply!"
    fi

    EDITOR_CONFIG=$HOME/.config/nvim
    EDITOR_CONFIG_FILE=$EDITOR_CONFIG/init.vim
}

# Injects a managed block in the vim configuration
inject_vim_configuration() {
    pre_step "Inject managed block in vim configuration"

    WORKING_PATH=$(git rev-parse --show-toplevel)
    
    if [[ -f $EDITOR_CONFIG_FILE ]]; then
        echo "Setting up NVIM configuration extras..."
        if ! grep -q "$BLOCK_DELIMITER_PATTERN" < "$EDITOR_CONFIG_FILE"; then
            printf "\" %s:start\nsource %s/files/extras.vim\n\" %s:end\n\n" \
                " $BLOCK_DELIMITER_PATTERN" "$WORKING_PATH" "$BLOCK_DELIMITER_PATTERN" \
                >> "$EDITOR_CONFIG_FILE".new
            cat "$EDITOR_CONFIG_FILE" >> "$EDITOR_CONFIG_FILE".new

            mv "$EDITOR_CONFIG_FILE" "$EDITOR_CONFIG_FILE".old
            mv "$EDITOR_CONFIG_FILE".new "$EDITOR_CONFIG_FILE"
            echo "✅ Added managed block to $EDITOR_CONFIG_FILE"
        else
            echo "No changes to apply!"
        fi
    fi

    echo "Setting up git configuration..."
    source "$WORKING_PATH"/files/git_config
    echo "✅ Set up git configuration, see $WORKING_PATH/files/git_config for details!"
}

###########################################################
#
# 3. Bootstrap sequence
#
###########################################################

bootstrap_home() {
    TOTAL_STEPS=10

    # System updates
    ensure_apt_up_to_date
    ensure_apt_dependencies
    
    # Development tooling and SDKs
    install_rust
    install_pyenv
    install_nvm
    install_gh_plugins

    # Shell & prompt setup
    install_omz
    install_and_configure_starship

    inject_shell_configuration
    inject_vim_configuration
}

bootstrap_work() {
    TOTAL_STEPS=4

    install_gh_plugins

    install_omz
    install_and_configure_starship

    inject_shell_configuration
    inject_vim_configuration
}

if [[ $ENV_PROFILE == "home" ]]; then
    bootstrap_home
elif [[ $ENV_PROFILE == "work" ]]; then
    bootstrap_work
else
    echo "Unknown \$ENV_PROFILE. :shrug:"
fi