package index

import (
	"context"
	"reflect"
	"testing"

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

const otherMerge = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"

func sourceOf(repo, head string) delivery.Source {
	return delivery.Source{Group: "g", Heads: map[string]string{repo: head}}
}

func TestASourceRevisionStampsTheModulesOfTheRepositoriesHeadItNames(t *testing.T) { // 1344/AC1
	ix, mods := modulesIndexer(t)
	ctx := context.Background()
	if err := ix.Apply(ctx, mergedMsg("novox/mesh-delivery", map[string]string{"modules/a": "newtree"})); err != nil {
		t.Fatal(err)
	}
	before, _ := moduleOf(t, mods, "a")
	if before.Src != 0 {
		t.Fatalf("module before the source = %+v, want Src 0", before)
	}
	// The source names the head merged for the delivery repository, and another repository's head no module of ours is built from.
	s := delivery.Source{Group: "g", Heads: map[string]string{"novox/mesh-delivery": merge, "novox/mesh-catalog": otherMerge}}
	if err := ix.ApplySource(ctx, 7, s); err != nil {
		t.Fatal(err)
	}
	m, ok := moduleOf(t, mods, "a")
	want := before
	want.Src = 7
	if !ok || !reflect.DeepEqual(m, want) {
		t.Errorf("module a = %+v (%v), want %+v: the fingerprint and the commit as the merge wrote them, with Src 7", m, ok, want)
	}
	if c, ok := moduleOf(t, mods, "c"); ok {
		t.Errorf("module c = %+v: written for a head no merge message of the indexer carried", c)
	}
	// The same revision again changes nothing; a later revision moves Src.
	if err := ix.ApplySource(ctx, 7, s); err != nil {
		t.Fatal(err)
	}
	if err := ix.ApplySource(ctx, 9, s); err != nil {
		t.Fatal(err)
	}
	if m, _ := moduleOf(t, mods, "a"); m.Src != 9 {
		t.Errorf("module a Src = %d, want 9", m.Src)
	}
}

func TestAMergeHeardAfterTheSourceNamesItsHeadIsStampedWhenWritten(t *testing.T) { // 1344/AC1 (the source first)
	ix, mods := modulesIndexer(t, rec(t, "build-1", "a", "novox/mesh-delivery", "modules/a", "main", "", "2026-10-19T09:00:00Z", aInputs))
	ctx := context.Background()
	if err := ix.ApplySource(ctx, 7, sourceOf("novox/mesh-delivery", merge)); err != nil {
		t.Fatal(err)
	}
	if _, ok := moduleOf(t, mods, "a"); ok {
		t.Fatal("a module was written from a source revision alone: its tree is the merge message's")
	}
	if err := ix.Apply(ctx, mergedMsg("novox/mesh-delivery", map[string]string{"modules/a": "newtree"})); err != nil {
		t.Fatal(err)
	}
	if m, ok := moduleOf(t, mods, "a"); !ok || m.Src != 7 || m.Commit != merge || m.Path != "modules/a" {
		t.Errorf("module a = %+v (%v), want the merge's fingerprint with Src 7", m, ok)
	}
}

func TestAMergeThatNoSourceRevisionNamesIsWrittenAsToday(t *testing.T) { // 1344/AC2
	ix, mods := modulesIndexer(t, rec(t, "build-1", "a", "novox/mesh-delivery", "modules/a", "main", "", "2026-10-19T09:00:00Z", aInputs))
	ctx := context.Background()
	// No source revision yet.
	if err := ix.Apply(ctx, mergedMsg("novox/mesh-delivery", map[string]string{"modules/a": "newtree"})); err != nil {
		t.Fatal(err)
	}
	if m, ok := moduleOf(t, mods, "a"); !ok || m.Src != 0 || m.Path != "modules/a" {
		t.Fatalf("module a = %+v (%v), want the merge written with Src 0", m, ok)
	}
	// A source revision that names another head of the repository: a merge of the head it does not name keeps Src 0.
	if err := ix.ApplySource(ctx, 7, sourceOf("novox/mesh-delivery", otherMerge)); err != nil {
		t.Fatal(err)
	}
	if m, _ := moduleOf(t, mods, "a"); m.Src != 0 {
		t.Errorf("module a Src = %d after a source naming another head, want 0", m.Src)
	}
	merged := mergedMsg("novox/mesh-delivery", map[string]string{"modules/a": "newertree"})
	merged.Merge = "cccccccccccccccccccccccccccccccccccccccc"
	if err := ix.Apply(ctx, merged); err != nil {
		t.Fatal(err)
	}
	if m, _ := moduleOf(t, mods, "a"); m.Src != 0 || m.Commit != merged.Merge {
		t.Errorf("module a = %+v, want the new merge with Src 0", m)
	}
}

func TestASourceRevisionOlderThanTheOneHeldIsLeft(t *testing.T) {
	ix, mods := modulesIndexer(t, rec(t, "build-1", "a", "novox/mesh-delivery", "modules/a", "main", "", "2026-10-19T09:00:00Z", aInputs))
	ctx := context.Background()
	_ = ix.Apply(ctx, mergedMsg("novox/mesh-delivery", map[string]string{"modules/a": "newtree"}))
	_ = ix.ApplySource(ctx, 9, sourceOf("novox/mesh-delivery", merge))
	_ = ix.ApplySource(ctx, 7, sourceOf("novox/mesh-delivery", merge))
	if m, _ := moduleOf(t, mods, "a"); m.Src != 9 {
		t.Errorf("module a Src = %d, want 9", m.Src)
	}
}