#!/usr/bin/env bash

# LICENSE
#   Copyright 2022 Jeffrey Serio <hyperreal@fedoraproject.org>
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <https://www.gnu.org/licenses/>.

set -eu
set -o pipefail
set -o posix

# Check for dependencies: curl and gum.
if ! test -x "$(command -v curl)"; then
    echo "Missing dependencies: curl"
    exit 1
fi

if ! test -x "$(command -v gum)"; then
    echo "Missing dependencies: gum"
    echo "See https://github.com/charmbracelet/gum"
    exit 1
fi

if ! test -x "$(command -v unzip)"; then
    echo "Missing dependencies: unzip"
    exit 1
fi

if ! test -x "$(command -v jq)"; then
    echo "Missing dependencies: jq"
    exit 1
fi

# Directory on the local filesystem where the fonts will be installed.
LOCAL_FONT_DIR="${HOME}/.local/share/fonts"

# Fancy error output message.
gum_error() {
    gum style \
        --foreground 3 \
        --border-foreground 203 \
        --border rounded \
        --align center \
        --width 50 \
        --margin "1 2" \
        "ERROR" \
        "" \
        "$1"
    exit 1
}

# Print the startup message.
message=$(echo "Nerd font installer :nerd_face:" | gum format -t emoji)
gum style \
    --foreground 212 \
    --border-foreground 57 \
    --border rounded \
    --align center \
    --width 50 \
    --margin "1 2" \
    "$message"

# Read the nerd-font download URLs into an array
readarray -t nf_url_array < <(curl --silent "https://api.github.com/repos/ryanoasis/nerd-fonts/releases/latest" | jq '.assets.[].browser_download_url' | tr -d '"' | grep ".zip")

# Add the nerd-font basenames without file extension suffix into an associative
# array, using these as the keys and the download URLs as the values.
declare -A nf_array
for nf in "${nf_url_array[@]}"; do
    name="$(basename -s .zip "$nf")"
    nf_array[$name]="$nf"
done

# Sort the keys of the array.
IFS=$'\n'
readarray -t sorted_keys < <(sort <<<"${!nf_array[*]}")
unset IFS

# Display nerd-font selection menu with the keys of the associative array.
selection=$(gum choose --height=10 --limit=1 "${sorted_keys[@]}")

# Prompt for user confirmation and proceed with installation of nerd fonts.
#
# For each nerd font selected, print a status message while downloading and
# installing the nerd font. Else print an error message if any of it fails.
#
# If user declines to proceed with installation, print a cancel message.
if gum confirm "Proceed with installation?"; then
    if ! gum spin --spinner dot --title "Downloading $selection..." \
        -- curl --create-dirs -f -sL -o "${LOCAL_FONT_DIR}/$selection.zip" "${nf_array["$selection"]}"; then
        gum_error "Failed to download nerdfont archive $selection"
    fi
    if ! gum spin --spinner dot --title "Installing $selection..." \
        -- unzip -uo "${LOCAL_FONT_DIR}/$selection.zip" -d "${LOCAL_FONT_DIR}"; then
        gum_error "Failed to install nerdfont archive $selection"
    fi
else
    gum style \
        --foreground 212 \
        --border-foreground 57 \
        --border rounded \
        --align center \
        --width 50 \
        --margin "1 2" \
        "Nerd font installation cancelled"
fi

# Clean up local font directory. Removes everything besides fonts.
if ! gum spin --spinner dot --title "Cleaning up local font directory..." \
    -- find "${LOCAL_FONT_DIR}" -mindepth 1 \
    -not -name "*.otf" \
    -not -name "*.ttf" \
    -not -name "static" \
    -exec rm -rf {} \;; then
    gum_error "Failed to clean up local font directory. Try doing it manually."
fi

# Update font cache
if ! gum spin --spinner dot --title "Updating font cache..." \
    -- fc-cache -f; then
    gum_error "Failed to update font cache."
fi

# Print a message stating which nerd fonts were installed.
gum format -t markdown -- \
    "# Successfully installed" \
    "$(printf "* %s\n" "${selection[@]}")"