#!/usr/bin/env nix-shell
#!nix-shell -I nixpkgs=./. -i bash -p curl jq nix gnused
# shellcheck shell=bash

set -Eeuo pipefail

cd "$(dirname "${BASH_SOURCE[0]}")"

release () {
  local content="$1"
  local version="$2"

  jq -r '.releases[] | select(."release-version" == "'"$version"'")' <<< "$content"
}

release_files () {
  local release="$1"
  local expr="$2"

  jq -r '[('"$expr"').files[] | select(.name | test("^.*.tar.gz$"))]' <<< "$release"
}

release_platform_attr () {
  local release_files="$1"
  local platform="$2"
  local attr="$3"

  jq -r '.[] | select((.rid == "'"$platform"'") and (.name | contains("composite") | not)) | ."'"$attr"'"' <<< "$release_files"
}

platform_sources () {
  local release_files="$1"
  local platforms=(
    "x86_64-linux   linux-x64"
    "aarch64-linux  linux-arm64"
    "x86_64-darwin  osx-x64"
    "aarch64-darwin osx-arm64"
  )

  echo "srcs = {"
  for kv in "${platforms[@]}"; do
    local nix_platform=${kv%% *}
    local ms_platform=${kv##* }

    local url=$(release_platform_attr "$release_files" "$ms_platform" url)
    local hash=$(release_platform_attr "$release_files" "$ms_platform" hash)

    [[ -z "$url" || -z "$hash" ]] && continue
    echo "      $nix_platform = {
        url     = \"$url\";
        sha512  = \"$hash\";
      };"
    done
    echo "    };"
}

generate_package_list() {
    local version pkgs nuget_url
    version="$1"
    shift
    pkgs=( "$@" )

    nuget_url="$(curl -f "https://api.nuget.org/v3/index.json" | jq --raw-output '.resources[] | select(."@type" == "PackageBaseAddress/3.0.0")."@id"')"

    for pkg in "${pkgs[@]}"; do
        local url hash
        url="${nuget_url}${pkg,,}/${version,,}/${pkg,,}.${version,,}.nupkg"
        hash="$(nix-prefetch-url "$url")"
        if [[ -z "$hash" ]]; then
            echo "Failed to fetch hash for $url" >&2
            exit 1
        fi

        echo "      (fetchNuGet { pname = \"${pkg}\"; version = \"${version}\"; sha256 = \"${hash}\"; })"
    done
}

version_older () {
    cur_version=$1
    max_version=$2
    result=$(nix-instantiate -I ../../../../. \
        --eval -E "(import ../../../../. {}).lib.versionOlder \"$cur_version\" \"$max_version\"")
    if [[ "$result" == "true" ]]; then
        return 0
    else
        return 1
    fi
}

aspnetcore_packages () {
    local version=$1
    # These packages are implicitly references by the build process,
    # based on the specific project configurations (RIDs, used features, etc.)
    # They are always referenced with the same version as the SDK used for building.
    # Since we lock nuget dependencies, when these packages are included in the generated
    # lock files (deps.nix), every update of SDK required those lock files to be
    # updated to reflect the new versions of these packages - otherwise, the build
    # would fail due to missing dependencies.
    #
    # Moving them to a separate list stored alongside the SDK package definitions,
    # and implicitly including them along in buildDotnetModule allows us
    # to make updating .NET SDK packages a lot easier - we now just update
    # the versions of these packages in one place, and all packages that
    # use buildDotnetModule continue building with the new .NET version without changes.
    #
    # Keep in mind that there is no canonical list of these implicitly
    # referenced packages - this list was created based on looking into
    # the deps.nix files of existing packages, and which dependencies required
    # updating after a SDK version bump.
    #
    # Due to this, make sure to check if new SDK versions introduce any new packages.
    # This should not happend in minor or bugfix updates, but probably happens
    # with every new major .NET release.
    local pkgs=(
      "Microsoft.AspNetCore.App.Runtime.linux-arm"
      "Microsoft.AspNetCore.App.Runtime.linux-arm64"
      "Microsoft.AspNetCore.App.Runtime.linux-musl-arm64"
      "Microsoft.AspNetCore.App.Runtime.linux-musl-x64"
      "Microsoft.AspNetCore.App.Runtime.linux-x64"
      "Microsoft.AspNetCore.App.Runtime.osx-x64"
      "Microsoft.AspNetCore.App.Runtime.win-arm64"
      "Microsoft.AspNetCore.App.Runtime.win-x64"
      "Microsoft.AspNetCore.App.Runtime.win-x86"
    )

    # These packages are currently broken on .NET 8
    if version_older "$version" "8"; then
        pkgs+=(
            "Microsoft.AspNetCore.App.Runtime.win-arm"
        )
    fi

    # Packages that only apply to .NET 6 and up
    if ! version_older "$version" "6"; then
        pkgs+=(
          "Microsoft.AspNetCore.App.Ref"
          "Microsoft.AspNetCore.App.Runtime.linux-musl-arm"
          "Microsoft.AspNetCore.App.Runtime.osx-arm64"
        )
    fi


    generate_package_list "$version" "${pkgs[@]}"
}

sdk_packages () {
    local version=$1
    # These packages are implicitly references by the build process,
    # based on the specific project configurations (RIDs, used features, etc.)
    # They are always referenced with the same version as the SDK used for building.
    # Since we lock nuget dependencies, when these packages are included in the generated
    # lock files (deps.nix), every update of SDK required those lock files to be
    # updated to reflect the new versions of these packages - otherwise, the build
    # would fail due to missing dependencies.
    #
    # Moving them to a separate list stored alongside the SDK package definitions,
    # and implicitly including them along in buildDotnetModule allows us
    # to make updating .NET SDK packages a lot easier - we now just update
    # the versions of these packages in one place, and all packages that
    # use buildDotnetModule continue building with the new .NET version without changes.
    #
    # Keep in mind that there is no canonical list of these implicitly
    # referenced packages - this list was created based on looking into
    # the deps.nix files of existing packages, and which dependencies required
    # updating after a SDK version bump.
    #
    # Due to this, make sure to check if new SDK versions introduce any new packages.
    # This should not happend in minor or bugfix updates, but probably happens
    # with every new major .NET release.
    local pkgs=(
      "Microsoft.NETCore.App.Host.linux-arm"
      "Microsoft.NETCore.App.Host.linux-arm64"
      "Microsoft.NETCore.App.Host.linux-musl-arm64"
      "Microsoft.NETCore.App.Host.linux-musl-x64"
      "Microsoft.NETCore.App.Host.linux-x64"
      "Microsoft.NETCore.App.Host.osx-x64"
      "Microsoft.NETCore.App.Host.win-arm64"
      "Microsoft.NETCore.App.Host.win-x64"
      "Microsoft.NETCore.App.Host.win-x86"
      "Microsoft.NETCore.App.Runtime.linux-arm"
      "Microsoft.NETCore.App.Runtime.linux-arm64"
      "Microsoft.NETCore.App.Runtime.linux-musl-arm64"
      "Microsoft.NETCore.App.Runtime.linux-musl-x64"
      "Microsoft.NETCore.App.Runtime.linux-x64"
      "Microsoft.NETCore.App.Runtime.osx-x64"
      "Microsoft.NETCore.App.Runtime.win-arm64"
      "Microsoft.NETCore.App.Runtime.win-x64"
      "Microsoft.NETCore.App.Runtime.win-x86"
      "Microsoft.NETCore.DotNetAppHost"
      "Microsoft.NETCore.DotNetHost"
      "Microsoft.NETCore.DotNetHostPolicy"
      "Microsoft.NETCore.DotNetHostResolver"
      "runtime.linux-arm64.Microsoft.NETCore.DotNetAppHost"
      "runtime.linux-arm64.Microsoft.NETCore.DotNetHost"
      "runtime.linux-arm64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.linux-arm64.Microsoft.NETCore.DotNetHostResolver"
      "runtime.linux-arm.Microsoft.NETCore.DotNetAppHost"
      "runtime.linux-arm.Microsoft.NETCore.DotNetHost"
      "runtime.linux-arm.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.linux-arm.Microsoft.NETCore.DotNetHostResolver"
      "runtime.linux-musl-arm64.Microsoft.NETCore.DotNetAppHost"
      "runtime.linux-musl-arm64.Microsoft.NETCore.DotNetHost"
      "runtime.linux-musl-arm64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.linux-musl-arm64.Microsoft.NETCore.DotNetHostResolver"
      "runtime.linux-musl-x64.Microsoft.NETCore.DotNetAppHost"
      "runtime.linux-musl-x64.Microsoft.NETCore.DotNetHost"
      "runtime.linux-musl-x64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.linux-musl-x64.Microsoft.NETCore.DotNetHostResolver"
      "runtime.linux-x64.Microsoft.NETCore.DotNetAppHost"
      "runtime.linux-x64.Microsoft.NETCore.DotNetHost"
      "runtime.linux-x64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.linux-x64.Microsoft.NETCore.DotNetHostResolver"
      "runtime.osx-x64.Microsoft.NETCore.DotNetAppHost"
      "runtime.osx-x64.Microsoft.NETCore.DotNetHost"
      "runtime.osx-x64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.osx-x64.Microsoft.NETCore.DotNetHostResolver"
      "runtime.win-arm64.Microsoft.NETCore.DotNetAppHost"
      "runtime.win-arm64.Microsoft.NETCore.DotNetHost"
      "runtime.win-arm64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.win-arm64.Microsoft.NETCore.DotNetHostResolver"
      "runtime.win-x64.Microsoft.NETCore.DotNetAppHost"
      "runtime.win-x64.Microsoft.NETCore.DotNetHost"
      "runtime.win-x64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.win-x64.Microsoft.NETCore.DotNetHostResolver"
      "runtime.win-x86.Microsoft.NETCore.DotNetAppHost"
      "runtime.win-x86.Microsoft.NETCore.DotNetHost"
      "runtime.win-x86.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.win-x86.Microsoft.NETCore.DotNetHostResolver"
      "Microsoft.NETCore.App.Host.linux-musl-arm"
      "Microsoft.NETCore.App.Host.osx-arm64"
      "Microsoft.NETCore.App.Runtime.linux-musl-arm"
      "Microsoft.NETCore.App.Runtime.osx-arm64"
      "Microsoft.NETCore.App.Ref"
      "Microsoft.NETCore.App.Runtime.Mono.linux-arm"
      "Microsoft.NETCore.App.Runtime.Mono.linux-arm64"
      "Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64"
      "Microsoft.NETCore.App.Runtime.Mono.linux-x64"
      "Microsoft.NETCore.App.Runtime.Mono.osx-arm64"
      "Microsoft.NETCore.App.Runtime.Mono.osx-x64"
      "Microsoft.NETCore.App.Runtime.Mono.win-x64"
      "Microsoft.NETCore.App.Runtime.Mono.win-x86"
      "runtime.linux-musl-arm.Microsoft.NETCore.DotNetAppHost"
      "runtime.linux-musl-arm.Microsoft.NETCore.DotNetHost"
      "runtime.linux-musl-arm.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.linux-musl-arm.Microsoft.NETCore.DotNetHostResolver"
      "runtime.osx-arm64.Microsoft.NETCore.DotNetAppHost"
      "runtime.osx-arm64.Microsoft.NETCore.DotNetHost"
      "runtime.osx-arm64.Microsoft.NETCore.DotNetHostPolicy"
      "runtime.osx-arm64.Microsoft.NETCore.DotNetHostResolver"
      "Microsoft.NETCore.App.Crossgen2.linux-musl-arm"
      "Microsoft.NETCore.App.Crossgen2.linux-musl-arm64"
      "Microsoft.NETCore.App.Crossgen2.linux-musl-x64"
      "Microsoft.NETCore.App.Crossgen2.linux-arm"
      "Microsoft.NETCore.App.Crossgen2.linux-arm64"
      "Microsoft.NETCore.App.Crossgen2.linux-x64"
      "Microsoft.NETCore.App.Crossgen2.osx-x64"
      "Microsoft.NETCore.App.Crossgen2.osx-arm64"
    )

    # These packages were removed on .NET 9
    if ! version_older "$version" "9"; then
      local newpkgs=()
      for pkg in "${pkgs[@]}"; do
        [[ "$pkg" = *Microsoft.NETCore.DotNetHost* ]] || newpkgs+=("$pkg")
      done
      pkgs=("${newpkgs[@]}")
    fi

    # These packages were removed on .NET 8
    if version_older "$version" "8"; then
        pkgs+=(
            "Microsoft.NETCore.App.Host.win-arm"
            "Microsoft.NETCore.App.Runtime.win-arm"
            "runtime.win-arm.Microsoft.NETCore.DotNetAppHost"
            "runtime.win-arm.Microsoft.NETCore.DotNetHost"
            "runtime.win-arm.Microsoft.NETCore.DotNetHostPolicy"
            "runtime.win-arm.Microsoft.NETCore.DotNetHostResolver"
            "Microsoft.NETCore.App.Composite"
        )
    fi

    # Packages that only apply to .NET 7 and up
    if ! version_older "$version" "7"; then
        pkgs+=(
          "runtime.linux-arm64.Microsoft.DotNet.ILCompiler"
          "runtime.linux-musl-arm64.Microsoft.DotNet.ILCompiler"
          "runtime.linux-musl-x64.Microsoft.DotNet.ILCompiler"
          "runtime.linux-x64.Microsoft.DotNet.ILCompiler"
          "runtime.osx-x64.Microsoft.DotNet.ILCompiler"
          "runtime.win-arm64.Microsoft.DotNet.ILCompiler"
          "runtime.win-x64.Microsoft.DotNet.ILCompiler"
        )
    fi

    # These packges were added on .NET 8
    if ! version_older "$version" "8"; then
        pkgs+=(
            "Microsoft.NET.ILLink.Tasks"
        )
    fi

    generate_package_list "$version" "${pkgs[@]}"
}

main () {
  pname=$(basename "$0")
  if [[ ! "$*" =~ ^.*[0-9]{1,}\.[0-9]{1,}.*$ ]]; then
    echo "Usage: $pname [sem-versions]
Get updated dotnet src (platform - url & sha512) expressions for specified versions

Examples:
  $pname 6.0.14 7.0.201    - specific x.y.z versions
  $pname 6.0 7.0           - latest x.y versions
" >&2
    exit 1
  fi

  for sem_version in "$@"; do
    echo "Generating ./versions/${sem_version}.nix"
    patch_specified=false
    # Check if a patch was specified as an argument.
    # If so, generate file for the specific version.
    # If only x.y version was provided, get the latest patch
    # version of the given x.y version.
    if [[ "$sem_version" =~ ^[0-9]{1,}\.[0-9]{1,}\.[0-9]{1,} ]]; then
        patch_specified=true
    elif [[ ! "$sem_version" =~ ^[0-9]{1,}\.[0-9]{1,}$ ]]; then
        continue
    fi

    # Make sure the x.y version is properly passed to .NET release metadata url.
    # Then get the json file and parse it to find the latest patch release.
    major_minor=$(sed 's/^\([0-9]*\.[0-9]*\).*$/\1/' <<< "$sem_version")
    content=$(curl -sL https://dotnetcli.blob.core.windows.net/dotnet/release-metadata/"$major_minor"/releases.json)
    major_minor_patch=$([ "$patch_specified" == true ] && echo "$sem_version" || jq -r '."latest-release"' <<< "$content")
    major_minor_underscore=${major_minor/./_}

    release_content=$(release "$content" "$major_minor_patch")
    aspnetcore_version=$(jq -r '."aspnetcore-runtime".version' <<< "$release_content")
    runtime_version=$(jq -r '.runtime.version' <<< "$release_content")
    mapfile -t sdk_versions < <(jq -r '.sdks[] | .version' <<< "$release_content" | sort -rn)

    # If patch was not specified, check if the package is already the latest version
    # If it is, exit early
    if [ "$patch_specified" == false ] && [ -f "./versions/${sem_version}.nix" ]; then
        current_version=$(nix-instantiate --eval -E "(import ./versions/${sem_version}.nix { \
            buildAspNetCore = { ... }: {}; \
            buildNetSdk = { ... }: {}; \
            buildNetRuntime = { ... }: {}; \
            }).release_${major_minor_underscore}" | jq -r)

        if [[ "$current_version" == "$major_minor_patch" ]]; then
            echo "Nothing to update."
            continue
        fi
    fi

    aspnetcore_files="$(release_files "$release_content" .\"aspnetcore-runtime\")"
    runtime_files="$(release_files "$release_content" .runtime)"

    channel_version=$(jq -r '."channel-version"' <<< "$content")
    support_phase=$(jq -r '."support-phase"' <<< "$content")

    aspnetcore_sources="$(platform_sources "$aspnetcore_files")"
    runtime_sources="$(platform_sources "$runtime_files")"

    sdk_packages="$(sdk_packages "${runtime_version}")"
    aspnetcore_packages="$(aspnetcore_packages "${aspnetcore_version}")"

    result=$(mktemp)
    trap "rm -f $result" TERM INT EXIT

    echo "{ buildAspNetCore, buildNetRuntime, buildNetSdk }:

# v$channel_version ($support_phase)

let
  packages = { fetchNuGet }: [
$aspnetcore_packages
$sdk_packages
  ];
in rec {
  release_$major_minor_underscore = \"$major_minor_patch\";

  aspnetcore_$major_minor_underscore = buildAspNetCore {
    version = \"${aspnetcore_version}\";
    $aspnetcore_sources
  };

  runtime_$major_minor_underscore = buildNetRuntime {
    version = \"${runtime_version}\";
    $runtime_sources
  };" > "${result}"

    declare -A feature_bands
    unset latest_sdk

    for sdk_version in "${sdk_versions[@]}"; do
      sdk_base_version=${sdk_version%-*}
      feature_band=${sdk_base_version:0:-2}xx
      # sometimes one release has e.g. both 8.0.202 and 8.0.203
      [[ ! ${feature_bands[$feature_band]+true} ]] || continue
      feature_bands[$feature_band]=$sdk_version
      sdk_files="$(release_files "$release_content" ".sdks[] | select(.version == \"$sdk_version\")")"
      sdk_sources="$(platform_sources "$sdk_files")"
      sdk_attrname=sdk_${feature_band//./_}
      [[ -v latest_sdk ]] || latest_sdk=$sdk_attrname

      echo "
  $sdk_attrname = buildNetSdk {
    version = \"${sdk_version}\";
    $sdk_sources
    inherit packages;
  };" >> "${result}"
    done

    echo "
  sdk_$major_minor_underscore = $latest_sdk;
}" >> "${result}"

    cp "${result}" "./versions/${sem_version}.nix"
    echo "Generated ./versions/${sem_version}.nix"
  done
}

main "$@"