package check

import (
	"context"
	"fmt"
	"strings"
	"testing"

	"github.com/nats-io/nats.go"

	"git.novox.be/novox/mesh-sdk/go/delivery"
)

// Issue 1820: a build step goes to a node whose build module is not heard (a laptop asleep, not yet marked offline by the
// watchman), and the bus answers "no responders". The check moves the step to another node of the same build module.

// deafNodes makes every tool on the named nodes fail as the bus does when nobody listens there; count says how many
// times the node was called.
func deafNodes(b *bench, deaf ...string) {
	for tool, h := range b.steps.handlers {
		h := h
		b.steps.handlers[tool] = func(c stepCall) (any, error) {
			for _, n := range deaf {
				if c.node == n {
					return nil, fmt.Errorf("%s on %s: %w", c.tool, c.node, nats.ErrNoResponders)
				}
			}
			return h(c)
		}
	}
}

func nodesOf(calls []stepCall) []string {
	var out []string
	for _, c := range calls {
		out = append(out, c.node)
	}
	return out
}

func TestAFetchThatNobodyAnswersMovesToAnotherBuildNode(t *testing.T) { // 1820/AC1
	b := newBench(t)
	b.ex.Toolchains = goEntries("ace", "g14")
	deafNodes(b, "ace")
	v := b.judge(t, caseOf(t, pullOf(repoA, 7, head1))).Verdict
	if v.State != delivery.VerdictPass {
		t.Fatalf("verdict = %+v, want a pass on the node that answers", v)
	}
	if got := nodesOf(b.steps.tool("fetch")); len(got) != 2 || got[0] != "ace" || got[1] != "g14" {
		t.Errorf("fetch went to %v, want ace (no responders) then g14", got)
	}
	for _, c := range b.steps.tool("test") {
		if c.node != "g14" {
			t.Errorf("a test went to %s, want g14 only", c.node)
		}
	}
	if len(v.Machines) != 1 || v.Machines[0] != "g14" {
		t.Errorf("machines = %v, want [g14]: ace ran nothing", v.Machines)
	}
}

func TestATestStepThatNobodyAnswersIsFetchedAgainOnAnotherNode(t *testing.T) { // 1820/AC2
	b := newBench(t)
	b.ex.Toolchains = goEntries("ace", "g14")
	// ace answers the fetch and the digest, then goes to sleep before the test.
	test := b.steps.handlers["build_go_test"]
	b.steps.handlers["build_go_test"] = func(c stepCall) (any, error) {
		if c.node == "ace" {
			return nil, fmt.Errorf("test on ace: %w", nats.ErrNoResponders)
		}
		return test(c)
	}
	v := b.judge(t, caseOf(t, pullOf(repoA, 7, head1))).Verdict
	if v.State != delivery.VerdictPass {
		t.Fatalf("verdict = %+v, want a pass", v)
	}
	if got := nodesOf(b.steps.tool("fetch")); len(got) != 2 || got[1] != "g14" {
		t.Errorf("fetch went to %v, want ace then g14 (the workspace was on ace)", got)
	}
	for _, c := range b.steps.tool("test") {
		if c.node == "g14" && c.args["workspace"] == nil {
			t.Errorf("a test on g14 has no workspace")
		}
	}
	if len(v.Machines) != 1 || v.Machines[0] != "g14" {
		t.Errorf("machines = %v, want [g14]", v.Machines)
	}
}

func TestWhenNoBuildNodeAnswersTheFailureNamesEveryNodeTried(t *testing.T) { // 1820/AC3
	b := newBench(t)
	b.ex.Toolchains = goEntries("ace", "g14", "shanks")
	deafNodes(b, "ace", "g14", "shanks")
	v := b.judge(t, caseOf(t, pullOf(repoA, 7, head1))).Verdict
	if v.State != delivery.VerdictFail {
		t.Fatalf("verdict = %+v, want a failure", v)
	}
	for _, n := range []string{"ace", "g14", "shanks"} {
		if !strings.Contains(v.Failed.Words, n) {
			t.Errorf("failure %q does not name %s", v.Failed.Words, n)
		}
	}
	if !IsNodesFailure(v) {
		t.Errorf("failure %q is not a failure of the nodes, so it would not be judged again when they change", v.Failed.Words)
	}
	if got := len(b.steps.tool("fetch")); got != 3 {
		t.Errorf("fetch was tried %d times, want once on each of 3 nodes", got)
	}
}

func TestAStepThatFailedForTheChangeIsNotMovedToAnotherNode(t *testing.T) { // 1820/AC4
	b := newBench(t)
	b.ex.Toolchains = goEntries("ace", "g14")
	b.steps.handlers["build_go_fetch"] = func(stepCall) (any, error) { return nil, fmt.Errorf("fetch on ace: the step failed: git exploded") }
	v := b.judge(t, caseOf(t, pullOf(repoA, 7, head1))).Verdict
	if v.State != delivery.VerdictFail || len(b.steps.tool("fetch")) != 1 {
		t.Errorf("verdict = %+v after %d fetches, want a failure after one", v, len(b.steps.tool("fetch")))
	}
}

func TestACanceledCheckIsNotMovedToAnotherNode(t *testing.T) { // 1820/AC4
	b := newBench(t)
	b.ex.Toolchains = goEntries("ace", "g14")
	ctx, cancel := context.WithCancel(context.Background())
	b.steps.handlers["build_go_fetch"] = func(stepCall) (any, error) {
		cancel()
		return nil, fmt.Errorf("fetch on ace: %w", nats.ErrNoResponders)
	}
	_, _ = b.ex.Judge(ctx, caseOf(t, pullOf(repoA, 7, head1)))
	if n := len(b.steps.tool("fetch")); n != 1 {
		t.Errorf("fetch was tried %d times after the check ended, want 1", n)
	}
}

func TestAPinReadThatNobodyAnswersIsTheForgesFailureNotABuildNodes(t *testing.T) { // 1820/AC5
	b := groupBench(t, "cb54756c3865")
	b.ex.Forge.(*fakeForge).err = fmt.Errorf("gitea.gitea_get_file: %w", nats.ErrNoResponders)
	v := b.judge(t, caseOf(t, pullOf(repoA, 7, head1), pullOf(repoSDK, 12, head2))).Verdict
	if v.State != delivery.VerdictFail || v.Failed.Machine != "forge" {
		t.Errorf("verdict = %+v, want a failure at the forge: no build node was to blame", v)
	}
}