#!/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"

ensure_deps() {
    local missing=()

    for cmd in jq curl python3; 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
}

github_api() {
    local path="$1"
    local auth_args=()

    if [ -n "${GITHUB_TOKEN:-}" ]; then
        auth_args=(-H "Authorization: Bearer $GITHUB_TOKEN")
    fi

    curl -fsSL \
        -H "Accept: application/vnd.github+json" \
        "${auth_args[@]}" \
        "https://api.github.com${path}"
}

list_versions() {
    local tool="$1" owner repo

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

    owner="$(jq -r --arg tool "$tool" '.[$tool].owner' "$MANIFEST")"
    repo="$(jq -r --arg tool "$tool" '.[$tool].repo' "$MANIFEST")"

    github_api "/repos/$owner/$repo/releases?per_page=100" | jq -r '.[].tag_name'
}

select_version() {
    local tool="$1"
    local versions

    versions="$(list_versions "$tool")"

    if [ -z "$versions" ]; then
        printf 'No releases found for %s\n' "$tool" >&2
        exit 1
    fi

    if command -v fzf >/dev/null 2>&1; then
        printf '%s\n' "$versions" | fzf --prompt="Select ${tool} version > " --height=20 --reverse
    else
        printf '%s\n' "$versions" | sed -n '1,20p' >&2
        printf 'fzf is not installed, so pass a version explicitly.\n' >&2
        exit 1
    fi
}

update_version() {
    local tool="$1" version="$2"
    local tmp_file

    if [ -z "$version" ]; then
        printf 'No version selected for %s\n' "$tool" >&2
        exit 1
    fi

    tmp_file="$(mktemp)"
    python3 - "$MANIFEST" "$tool" "$version" "$tmp_file" <<'PY'
import json
import pathlib
import sys

manifest_path = pathlib.Path(sys.argv[1])
tool = sys.argv[2]
version = sys.argv[3]
tmp_path = pathlib.Path(sys.argv[4])

data = json.loads(manifest_path.read_text())
if tool not in data:
    raise SystemExit(f"Unsupported tool: {tool}")

data[tool]["version"] = version
tmp_path.write_text(json.dumps(data, indent=2) + "\n")
PY

    mv "$tmp_file" "$MANIFEST"
    printf 'Pinned %s to %s\n' "$tool" "$version"
}

main() {
    local mode="update" tool version

    ensure_deps

    if [ "${1:-}" = "--list" ]; then
        mode="list"
        shift
    fi

    tool="${1:-}"
    version="${2:-}"

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

    case "$mode" in
        list)
            list_versions "$tool"
            ;;
        update)
            if [ -z "$version" ]; then
                version="$(select_version "$tool")"
            fi
            update_version "$tool" "$version"
            ;;
    esac
}

main "$@"