package buildstep

import (
	"encoding/base64"
	"encoding/json"
	"errors"
	"strings"
	"testing"
)

// Design 47 G A-254: one reader of a run's answer from a step-ended, inline or through the seat's verb output on the node that ran it.
func TestStepEndedReadOutput(t *testing.T) {
	const ask = "m2kx9a1b3c4d5f"
	var key string
	var body map[string]any
	verb := func(answer string, err error) AskVerb {
		return func(k string, b any) (json.RawMessage, error) {
			key = k
			body, _ = b.(map[string]any)
			return json.RawMessage(answer), err
		}
	}
	for _, c := range []struct {
		name    string
		end     StepEnded
		ask     AskVerb
		want    string
		wantKey string
		fail    string
	}{
		{name: "inline", end: StepEnded{Ask: ask, Node: "ace", Output: `{"a":1}`}, want: `{"a":1}`},
		{name: "an object is read through the verb on its node", end: StepEnded{Ask: ask, Node: "ace", OutputObject: OutputObjectName(ask)},
			ask: verb(`{"ask":"`+ask+`","file":"eyJhIjoxfQ=="}`, nil), want: `{"a":1}`, wantKey: "seat:node-build-go.output@ace"},
		{name: "no answer kept", end: StepEnded{Ask: ask, Node: "ace", OutputObject: "o"}, ask: verb(`{"ask":"`+ask+`","chunks":0}`, nil), fail: "keeps no answer"},
		{name: "another ask's answer", end: StepEnded{Ask: ask, Node: "ace", OutputObject: "o"}, ask: verb(`{"ask":"x","file":"e30="}`, nil), fail: "answered the ask"},
		{name: "the verb fails", end: StepEnded{Ask: ask, Node: "ace", OutputObject: "o"}, ask: verb(``, errors.New("no seat")), fail: "no seat"},
		{name: "no verb", end: StepEnded{Ask: ask, Node: "ace", OutputObject: "o"}, fail: "no verb"},
	} {
		t.Run(c.name, func(t *testing.T) {
			key, body = "", nil
			got, err := c.end.ReadOutput("go", c.ask)
			if c.fail != "" {
				if err == nil || !strings.Contains(err.Error(), c.fail) {
					t.Fatalf("err %v, want %q", err, c.fail)
				}
				return
			}
			if err != nil || string(got) != c.want || key != c.wantKey {
				t.Fatalf("got %q, %v on %q, want %q on %q", got, err, key, c.want, c.wantKey)
			}
			if c.wantKey != "" && (body["ask"] != ask || len(body["call"].(string)) != 32) {
				t.Fatalf("asked with %v, want the ask and 128 random bits as call", body)
			}
		})
	}
}

// A step-ended names its answer inline or as an object, never both.
func TestStepEndedRefusesAnswerTwice(t *testing.T) {
	e := StepEnded{ID: "m2kx9a1b3c4d5f", Ask: "m2kx9a1b3c4d5f", Asker: "a", Node: "ace", Outcome: OutcomePassed, Output: "1", OutputObject: "o"}
	if _, err := EncodeStepEnded(e); err == nil || !strings.Contains(err.Error(), "inline and as an object") {
		t.Fatalf("err %v", err)
	}
}

// Design 47 G A-290: a step whose key names its answer as an object is read whole through the seat's verb output on its
// node: a check's answer as its result, a run's output put back in its run answer; a key holding its answer is answered as it is.
func TestStepWholeReadsTheObjectItsKeyNames(t *testing.T) {
	const ask = "m2kx9a1b3c4d5f"
	var key string
	verb := func(file string, err error) AskVerb {
		return func(k string, _ any) (json.RawMessage, error) {
			key = k
			return json.RawMessage(`{"ask":"` + ask + `","file":"` + file + `"}`), err
		}
	}
	b64 := func(s string) string { return base64.StdEncoding.EncodeToString([]byte(s)) }
	named := Step{ID: ask, Node: "ace", State: StepPassed, OutputObject: OutputObjectName(ask)}
	for _, c := range []struct {
		name       string
		step       Step
		run        bool
		ask        AskVerb
		want, fail string
	}{
		{name: "the key holds it", step: Step{ID: ask, Node: "ace", Result: json.RawMessage(`{"a":1}`)}, want: `{"a":1}`},
		{name: "a check's answer", step: named, ask: verb(b64(`{"fetch":{"workspace":"w"}}`), nil), want: `{"fetch":{"workspace":"w"}}`},
		{name: "a run's output", step: func() Step { s := named; s.Result = json.RawMessage(`{"built":true,"key":"k","exit":0}`); return s }(), run: true,
			ask: verb(b64(`{"verdict":"ok"}`), nil), want: `{"built":true,"key":"k","exit":0,"output":{"verdict":"ok"}}`},
		{name: "a check's answer that is no JSON", step: named, ask: verb(b64(`not json`), nil), fail: "not JSON"},
		{name: "the verb fails", step: named, ask: verb("", errors.New("no responders")), fail: "no responders"},
		{name: "no verb", step: named, fail: "no verb"},
	} {
		t.Run(c.name, func(t *testing.T) {
			key = ""
			got, err := c.step.Whole("go", c.run, c.ask)
			if c.fail != "" {
				if err == nil || !strings.Contains(err.Error(), c.fail) {
					t.Fatalf("err %v, want %q", err, c.fail)
				}
				return
			}
			if err != nil || string(got.Result) != c.want || got.OutputObject != "" {
				t.Fatalf("got %s (object %q), %v; want %s", got.Result, got.OutputObject, err, c.want)
			}
			if c.ask != nil && key != "seat:node-build-go.output@ace" {
				t.Fatalf("asked %q", key)
			}
		})
	}
}