#!/bin/bash

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(dirname "$(dirname "$SCRIPT_DIR")")"
MANIFEST="$REPO_ROOT/Bins/versions.json"
TARGET_DIR="$HOME/.local/bin"

ensure_deps() {
    local missing=()

    for cmd in jq curl tar; do
        if ! command -v "$cmd" >/dev/null 2>&1; then
            missing+=("$cmd")
        fi
    done

    if [ "${#missing[@]}" -gt 0 ]; then
        printf 'Missing required commands: %s\n' "${missing[*]}" >&2
        exit 1
    fi
}

detect_platform() {
    case "$(uname -s)" in
        Linux) printf 'linux\n' ;;
        Darwin) printf 'macos\n' ;;
        *)
            printf 'Unsupported operating system: %s\n' "$(uname -s)" >&2
            exit 1
            ;;
    esac
}

detect_arch() {
    case "$(uname -m)" in
        x86_64) printf 'x86_64\n' ;;
        aarch64|arm64) printf 'aarch64\n' ;;
        *)
            printf 'Unsupported architecture: %s\n' "$(uname -m)" >&2
            exit 1
            ;;
    esac
}

install_tool() {
    local tool="$1"
    local platform arch version owner repo asset binary_rel formula url tmp_dir archive_path extracted_path target_path installed_path

    platform="$(detect_platform)"
    arch="$(detect_arch)"

    if ! jq -e --arg tool "$tool" '.[$tool]' "$MANIFEST" >/dev/null; then
        printf 'Unsupported tool: %s\n' "$tool" >&2
        exit 1
    fi

    version="$(jq -r --arg tool "$tool" '.[$tool].version' "$MANIFEST")"
    owner="$(jq -r --arg tool "$tool" '.[$tool].owner' "$MANIFEST")"
    repo="$(jq -r --arg tool "$tool" '.[$tool].repo' "$MANIFEST")"
    formula="$(jq -r --arg tool "$tool" --arg platform "$platform" '.[$tool][$platform].formula // empty' "$MANIFEST")"

    if [ -n "$formula" ]; then
        if ! command -v brew >/dev/null 2>&1; then
            printf 'Homebrew is required to install %s on macOS\n' "$tool" >&2
            exit 1
        fi

        if ! brew list --formula "$formula" >/dev/null 2>&1; then
            printf 'Installing %s via Homebrew formula %s\n' "$tool" "$formula"
            brew install "$formula"
        else
            printf '%s already installed via Homebrew\n' "$tool"
        fi

        installed_path="$(command -v "$tool" || true)"
        if [ -z "$installed_path" ]; then
            printf 'Installed formula %s but %s is not on PATH\n' "$formula" "$tool" >&2
            exit 1
        fi

        mkdir -p "$TARGET_DIR"
        target_path="$TARGET_DIR/$tool"
        ln -sf "$installed_path" "$target_path"
        printf 'Linked %s -> %s\n' "$target_path" "$installed_path"
        return 0
    fi

    asset="$(jq -r --arg tool "$tool" --arg platform "$platform" --arg arch "$arch" '.[$tool][$platform][$arch].asset // empty' "$MANIFEST")"
    binary_rel="$(jq -r --arg tool "$tool" --arg platform "$platform" --arg arch "$arch" '.[$tool][$platform][$arch].binary // empty' "$MANIFEST")"

    if [ -z "$asset" ] || [ -z "$binary_rel" ]; then
        printf 'No %s asset mapping for %s on %s\n' "$platform" "$tool" "$arch" >&2
        exit 1
    fi

    mkdir -p "$TARGET_DIR"
    tmp_dir="$(mktemp -d)"
    archive_path="$tmp_dir/$asset"
    url="https://github.com/$owner/$repo/releases/download/$version/$asset"

    printf 'Installing %s %s\n' "$tool" "$version"
    curl -fL "$url" -o "$archive_path"
    tar -xzf "$archive_path" -C "$tmp_dir"

    extracted_path="$tmp_dir/$binary_rel"
    if [ ! -f "$extracted_path" ]; then
        printf 'Expected binary not found after extraction: %s\n' "$binary_rel" >&2
        rm -rf "$tmp_dir"
        exit 1
    fi

    target_path="$TARGET_DIR/$tool"
    install -m 755 "$extracted_path" "$target_path"
    rm -rf "$tmp_dir"

    printf 'Installed %s -> %s\n' "$tool" "$target_path"
}

main() {
    ensure_deps

    if [ "${1:-}" = "--all" ]; then
        while IFS= read -r tool; do
            install_tool "$tool"
        done < <(jq -r 'keys[]' "$MANIFEST")
        exit 0
    fi

    if [ -z "${1:-}" ]; then
        printf 'Usage: %s [--all|tool]\n' "$0" >&2
        exit 1
    fi

    install_tool "$1"
}

main "$@"