#!/usr/bin/env bash
set -euo pipefail

INSTALL_API="https://install.ace.githubnext.com"

platform=$(uname -ms)

# Windows detection - use MINGW64 bash
if [[ ${OS:-} = Windows_NT ]]; then
    if [[ $platform != MINGW64* ]]; then
        # TODO: powershell installer
        echo "Please use Git Bash (MINGW64) to run this installer on Windows" >&2
        exit 1
    fi
fi

# Colors (only if terminal supports it)
Color_Off=''
Red=''
Green=''
Dim=''

if [[ -t 1 ]]; then
    Color_Off='\033[0m'
    Red='\033[0;31m'
    Green='\033[38;2;125;166;139m'
    Dim='\033[0;2m'
fi

error() {
    echo -e "  ${Red}error${Color_Off}:" "$@" >&2
    exit 1
}

info() {
    echo -e "  ${Dim}$@${Color_Off}"
}

# Check for required tools
command -v curl >/dev/null || error "'curl' is required but not installed"
command -v unzip >/dev/null || error "'unzip' is required but not installed"

# Parse arguments
usage() {
    cat <<EOF
Ace TUI Installer

Options:
    -h, --help              Display this help message
    -v, --version <version> Install a specific version (e.g., 1.0.0)
        --no-modify-path    Do not modify shell config files

Examples:
    curl -fsSL $INSTALL_API | bash
    curl -fsSL $INSTALL_API | bash -s -- --version 1.0.0
EOF
}

requested_version=""
no_modify_path=false

while [[ $# -gt 0 ]]; do
    case "$1" in
        -h|--help)
            usage
            exit 0
            ;;
        -v|--version)
            [[ -n "${2:-}" ]] || error "--version requires a version argument"
            requested_version="$2"
            shift 2
            ;;
        --no-modify-path)
            no_modify_path=true
            shift
            ;;
        *)
            error "Unknown option: $1"
            ;;
    esac
done

# Detect platform
case "$platform" in
    'Darwin x86_64')
        target=darwin-x64
        ;;
    'Darwin arm64')
        target=darwin-arm64
        ;;
    'Linux aarch64' | 'Linux arm64')
        target=linux-arm64
        ;;
    'Linux x86_64')
        target=linux-x64
        ;;
    MINGW64*)
        target=windows-x64
        ;;
    *)
        target=linux-x64
        ;;
esac

# Check for musl on Linux
case "$target" in
    'linux'*)
        if [[ -f /etc/alpine-release ]]; then
            target="$target-musl"
        elif command -v ldd >/dev/null 2>&1 && ldd --version 2>&1 | grep -qi musl; then
            target="$target-musl"
        fi
        ;;
esac

# Rosetta detection on macOS
if [[ $target = darwin-x64 ]]; then
    if [[ $(sysctl -n sysctl.proc_translated 2>/dev/null) = 1 ]]; then
        target=darwin-arm64
        info "Running in Rosetta 2, downloading arm64 binary instead"
    fi
fi

# Set up install directory
install_dir="${ACE_INSTALL:-$HOME/.ace}"
bin_dir="$install_dir/bin"

# Display path: use ~ for $HOME, otherwise show full path
if [[ $install_dir = $HOME/* ]]; then
    display_dir="~${install_dir#$HOME}"
else
    display_dir="$install_dir"
fi
display_bin="$display_dir/bin"

if [[ $target = windows-x64 ]]; then
    exe="$bin_dir/ace.exe"
    display_exe="$display_bin/ace.exe"
else
    exe="$bin_dir/ace"
    display_exe="$display_bin/ace"
fi

mkdir -p "$bin_dir" || error "Failed to create install directory: $bin_dir"

if [[ -z "$requested_version" ]]; then
    # Get latest version (follows 307 redirect to versioned endpoint)
    release_info=$(curl -sfL "$INSTALL_API/tui/latest") || error "Failed to fetch latest release info"
    version=$(echo "$release_info" | sed -n 's/.*"version"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/p')
    [[ -n "$version" ]] || error "Failed to parse version from release info"
    download_url="$INSTALL_API/tui/latest/$target"
else
    version="${requested_version#v}"
    # Verify release exists (use GET, not HEAD - server only handles GET)
    http_code=$(curl -s -o /dev/null -w "%{http_code}" "$INSTALL_API/tui/$version")
    [[ "$http_code" != "404" ]] || error "Release v$version not found"
    download_url="$INSTALL_API/tui/$version/$target"
fi

# Check if already installed
if command -v ace >/dev/null 2>&1; then
    installed=$(ace --version 2>/dev/null || echo "")
    if [[ "$installed" = "$version" ]]; then
        echo ""
        echo -e "  ${Green}ace v$version is already installed${Color_Off}"
        echo ""
        exit 0
    fi
fi

# Progress bar utilities
unbuffered_sed() {
    if echo | sed -u -e "" >/dev/null 2>&1; then
        sed -nu "$@"
    elif echo | sed -l -e "" >/dev/null 2>&1; then
        sed -nl "$@"
    else
        local pad="$(printf "\n%512s" "")"
        sed -ne "s/$/\\${pad}/" "$@"
    fi
}

print_progress() {
    local bytes="$1"
    local length="$2"
    [ "$length" -gt 0 ] || return 0

    local width=50
    local percent=$(( bytes * 100 / length ))
    [ "$percent" -gt 100 ] && percent=100
    local on=$(( percent * width / 100 ))
    local off=$(( width - on ))

    local filled=$(printf "%*s" "$on" "")
    filled=${filled// /■}
    local empty=$(printf "%*s" "$off" "")
    empty=${empty// /･}

    printf "\r  ${Green}%s%s %3d%%${Color_Off}" "$filled" "$empty" "$percent" >&4
}

download_with_progress() {
    local url="$1"
    local output="$2"

    if [ -t 2 ]; then
        exec 4>&2
    else
        exec 4>/dev/null
    fi

    local tmp_dir=${TMPDIR:-/tmp}
    local basename="${tmp_dir}/ace_install_$$"
    local tracefile="${basename}.trace"

    rm -f "$tracefile"
    mkfifo "$tracefile"

    # Hide cursor
    printf "\033[?25l" >&4

    trap "trap - RETURN; rm -f \"$tracefile\"; printf '\033[?25h' >&4; exec 4>&-" RETURN

    (
        curl --trace-ascii "$tracefile" -s -L -o "$output" "$url"
    ) &
    local curl_pid=$!

    unbuffered_sed \
        -e 'y/ACDEGHLNORTV/acdeghlnortv/' \
        -e '/^0000: content-length:/p' \
        -e '/^<= recv data/p' \
        "$tracefile" | \
    {
        local length=0
        local bytes=0

        while IFS=" " read -r -a line; do
            [ "${#line[@]}" -lt 2 ] && continue
            local tag="${line[0]} ${line[1]}"

            if [ "$tag" = "0000: content-length:" ]; then
                length="${line[2]}"
                length=$(echo "$length" | tr -d '\r')
                bytes=0
            elif [ "$tag" = "<= recv" ]; then
                local size="${line[3]}"
                bytes=$(( bytes + size ))
                if [ "$length" -gt 0 ]; then
                    print_progress "$bytes" "$length"
                fi
            fi
        done
    }

    wait $curl_pid
    local ret=$?
    echo "" >&4
    return $ret
}

info "Installing ace v$version for $target"

# Download with progress bar (fallback to curl progress on Windows/non-TTY)
if [[ "$target" == windows-* ]] || ! [ -t 2 ] || ! download_with_progress "$download_url" "$exe.zip"; then
    curl --fail --location --progress-bar --output "$exe.zip" "$download_url" ||
        error "Failed to download ace from $download_url"
fi

# Extract
unzip -oqd "$bin_dir" "$exe.zip" || error "Failed to extract ace"

# Move binary (handles nested directory from zip)
if [[ -d "$bin_dir/ace-$target" ]]; then
    if [[ $target = windows-x64 ]]; then
        mv "$bin_dir/ace-$target/ace.exe" "$exe"
    else
        mv "$bin_dir/ace-$target/ace" "$exe"
    fi
    rm -rf "$bin_dir/ace-$target"
fi

chmod +x "$exe"
rm -f "$exe.zip"

info "ace v$version installed to $display_exe"

# Add to PATH (if not already there)
if command -v ace >/dev/null; then
    : # ace already in PATH
elif [[ "$no_modify_path" = "true" ]]; then
    : # user opted out
else
    # Use $HOME in the export so it's portable
    path_cmd="export PATH=\"\$HOME/.ace/bin:\$PATH\""

    # Helper to display config path with ~ for $HOME
    display_config() {
        if [[ $1 = $HOME/* ]]; then
            echo "~${1#$HOME}"
        else
            echo "$1"
        fi
    }

    case $(basename "$SHELL") in
    fish)
        fish_config=$HOME/.config/fish/config.fish
        fish_cmd="fish_add_path \$HOME/.ace/bin"
        if [[ -w $fish_config ]]; then
            if ! grep -Fq "fish_add_path" "$fish_config" || ! grep -Fq ".ace/bin" "$fish_config"; then
                {
                    echo -e '\n# GitHub Ace'
                    echo "$fish_cmd"
                } >> "$fish_config"
                info "Added $display_bin to \$PATH in $(display_config "$fish_config")"
            fi
        else
            echo "  Manually add to $(display_config "$fish_config"):"
            echo "    $fish_cmd"
        fi
        ;;
    zsh)
        zsh_config=${ZDOTDIR:-$HOME}/.zshrc
        if [[ -w $zsh_config ]]; then
            if ! grep -Fq ".ace/bin" "$zsh_config"; then
                {
                    echo -e '\n# GitHub Ace'
                    echo "$path_cmd"
                } >> "$zsh_config"
                info "Added $display_bin to \$PATH in $(display_config "$zsh_config")"
            fi
        else
            echo "  Manually add to $(display_config "$zsh_config"):"
            echo "    $path_cmd"
        fi
        ;;
    bash)
        for bash_config in "$HOME/.bashrc" "$HOME/.bash_profile"; do
            if [[ -w $bash_config ]]; then
                if ! grep -Fq ".ace/bin" "$bash_config"; then
                    {
                        echo -e '\n# GitHub Ace'
                        echo "$path_cmd"
                    } >> "$bash_config"
                    info "Added $display_bin to \$PATH in $(display_config "$bash_config")"
                fi
                break
            fi
        done
        ;;
    *)
        echo "  Manually add to your shell config:"
        echo "    $path_cmd"
        ;;
    esac
fi

# GitHub Actions support
if [[ "${GITHUB_ACTIONS:-}" = "true" ]]; then
    echo "$bin_dir" >> "$GITHUB_PATH"
    info "Added $bin_dir to \$GITHUB_PATH"
fi

# Success message
echo ""
echo -e "  ${Green} █████╗  ██████╗███████╗${Color_Off}"
echo -e "  ${Green}██╔══██╗██╔════╝██╔════╝${Color_Off}"
echo -e "  ${Green}███████║██║     █████╗  ${Color_Off}"
echo -e "  ${Green}██╔══██║██║     ██╔══╝  ${Color_Off}"
echo -e "  ${Green}██║  ██║╚██████╗███████╗${Color_Off}"
echo -e "  ${Green}╚═╝  ╚═╝ ╚═════╝╚══════╝${Color_Off}"
echo ""
echo -e "  ${Dim}To get started:${Color_Off}"
echo ""
echo -e "    ace          ${Dim}# Start Ace${Color_Off}"
echo -e "    ace --help   ${Dim}# Display help${Color_Off}"
echo ""