package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"gopkg.in/yaml.v3"
)

type pinValues struct {
	Image struct {
		Digest string `yaml:"digest"`
	} `yaml:"image"`
	Args []string `yaml:"args"`
}

func loadPinValues(t *testing.T, name string) pinValues {
	t.Helper()
	raw, err := os.ReadFile(filepath.Join("..", "..", "values", name))
	if err != nil {
		t.Fatal(err)
	}
	var v pinValues
	if err := yaml.Unmarshal(raw, &v); err != nil {
		t.Fatal(err)
	}
	return v
}

func argAfter(args []string, flag string) []string {
	var out []string
	for i := 0; i+1 < len(args); i++ {
		if args[i] == flag {
			out = append(out, args[i+1])
		}
	}
	return out
}

// FLEX-WP-0035-T04, contract §4: the readback pin runs each participant's
// package at the same digest its own pin runs. The package is baked into the
// image, so same image digest and same path is the same package digest.
func TestReadbackPinMatchesParticipantPins(t *testing.T) {
	readback := loadPinValues(t, "application-readback.yaml")
	if len(readback.Args) == 0 || readback.Args[0] != "serve-readback" {
		t.Fatal("readback pin must run serve-readback, which mounts no /v1/check")
	}
	participants := map[string]string{"informed-decision": "informed-decision-lifecycle.yaml"}
	packages := argAfter(readback.Args, "--package")
	if len(packages) != len(participants) {
		t.Fatalf("readback packages %v, want one per participant %v", packages, participants)
	}
	for _, pkg := range packages {
		system, path, _ := strings.Cut(pkg, "=")
		file, ok := participants[system]
		if !ok {
			t.Fatalf("readback package for %q has no participant pin", system)
		}
		own := loadPinValues(t, file)
		if own.Image.Digest != readback.Image.Digest {
			t.Errorf("%s: readback image %s, own pin %s", system, readback.Image.Digest, own.Image.Digest)
		}
		if policies := argAfter(own.Args, "--policy"); len(policies) != 1 || policies[0] != path {
			t.Errorf("%s: readback package %s, own pin %v", system, path, policies)
		}
		if !strings.Contains(strings.Join(argAfter(readback.Args, "--registry"), " "), strings.Join(argAfter(own.Args, "--registry"), " ")) {
			t.Errorf("%s: readback pin does not load its registry", system)
		}
	}
}