package builder

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

	"github.com/novox/mesh-controller/internal/catalogue"
)

// A module naming a base the mesh has not built is refused, and the refusal names what is missing.
//
// **This is the whole point of naming a base rather than pinning one** (novox/hq issue 044). A
// recipe with a fingerprint typed into it fails inside a container runtime, on its first line, with
// a message about an image nobody can look up. This fails before anything is built, saying which
// module has to exist first.
func TestABaseTheMeshHasNotBuiltIsRefused(t *testing.T) {
	manifest := catalogue.Manifest{
		Module: "postgres",
		Build: &catalogue.Build{
			On: []catalogue.BuildsOn{{Arg: "RUNTIME_BASE", Module: "mesh-tools", Artifact: "runtime"}},
		},
	}
	_, _, err := standingOn(context.Background(), manifest, map[string]string{}, noMirror)
	if err == nil {
		t.Fatal("a base nothing has built was accepted; the build would have failed on its first line")
	}
	for _, want := range []string{"mesh-tools", "postgres"} {
		if !strings.Contains(err.Error(), want) {
			t.Errorf("the refusal does not name %s: %v", want, err)
		}
	}
}

// And one the mesh holds becomes the argument the recipe reads it from.
func TestABaseTheMeshHoldsBecomesABuildArgument(t *testing.T) {
	manifest := catalogue.Manifest{
		Module: "postgres",
		Build: &catalogue.Build{
			On: []catalogue.BuildsOn{{Arg: "RUNTIME_BASE", Module: "mesh-tools", Artifact: "runtime"}},
		},
	}
	held := map[string]string{"mesh-tools/runtime": "127.0.0.1:5000/mesh-tools/runtime@sha256:" + strings.Repeat("a", 64)}
	args, _, err := standingOn(context.Background(), manifest, held, noMirror)
	if err != nil {
		t.Fatalf("a base this mesh holds was refused: %v", err)
	}
	want := []string{"--build-arg", "RUNTIME_BASE=" + held["mesh-tools/runtime"]}
	if len(args) != len(want) || args[0] != want[0] || args[1] != want[1] {
		t.Fatalf("the build was invoked with %v, not %v", args, want)
	}
}

// A module naming no base asks for nothing, which is most modules.
func TestAModuleNamingNoBaseAddsNoArguments(t *testing.T) {
	args, _, err := standingOn(context.Background(), catalogue.Manifest{Module: "hello-web", Build: &catalogue.Build{}}, nil, noMirror)
	if err != nil || args != nil {
		t.Fatalf("a module naming no base produced %v, %v", args, err)
	}
}

// Half a base is refused rather than half-applied.
func TestAnIncompleteBaseIsRefused(t *testing.T) {
	manifest := catalogue.Manifest{
		Module: "postgres",
		Build:  &catalogue.Build{On: []catalogue.BuildsOn{{Module: "mesh-tools", Artifact: "runtime"}}},
	}
	if _, _, err := standingOn(context.Background(), manifest, map[string]string{"mesh-tools/runtime": "x"}, noMirror); err == nil {
		t.Fatal("a base with no build argument was accepted; nothing would have read it")
	}
}

// noMirror is a mirror for tests whose bases are all the mesh's own.
func noMirror(context.Context, string, string) (string, error) {
	return "", fmt.Errorf("nothing to copy in this test")
}

// A build may stand on an image published elsewhere, declared and pinned (novox/hq 04-ISSUES/064,
// ADR 0097): it is copied into the mesh's registry first and the recipe is handed the copy.
func TestADeclaredVendorImageIsCopiedInAndHandedToTheRecipe(t *testing.T) {
	manifest := catalogue.Manifest{
		Module: "minio",
		Build: &catalogue.Build{
			On: []catalogue.BuildsOn{{Arg: "MC_BASE", Image: "quay.io/minio/mc@sha256:" + strings.Repeat("c", 64)}},
		},
	}
	var asked []string
	args, _, err := standingOn(context.Background(), manifest, nil, func(_ context.Context, from, repository string) (string, error) {
		asked = append(asked, from+" -> "+repository)
		return "127.0.0.1:5000/" + repository + "@sha256:" + strings.Repeat("d", 64), nil
	})
	if err != nil {
		t.Fatal(err)
	}
	if len(asked) != 1 || asked[0] != "quay.io/minio/mc@sha256:"+strings.Repeat("c", 64)+" -> minio/on-mc_base" {
		t.Fatalf("the image was not copied under the module's repository: %v", asked)
	}
	if strings.Join(args, " ") != "--build-arg MC_BASE=127.0.0.1:5000/minio/on-mc_base@sha256:"+strings.Repeat("d", 64) {
		t.Fatalf("the recipe was not handed the copy: %v", args)
	}
	// Unpinned, it is refused: a tag is what somebody else can move.
	manifest.Build.On[0].Image = "quay.io/minio/mc:latest"
	if _, _, err := standingOn(context.Background(), manifest, nil, noMirror); err == nil || !strings.Contains(err.Error(), "not pinned") {
		t.Fatalf("an unpinned vendor image was accepted: %v", err)
	}
}

// A recipe reaching for an image the manifest did not declare is named, and its own stages,
// declared arguments and scratch are not.
func TestARecipeFetchingWhatTheManifestDidNotDeclareIsNamed(t *testing.T) {
	recipe := `
ARG RUNTIME_BASE
ARG MC_BASE
FROM ${RUNTIME_BASE} AS build
COPY --from=${MC_BASE} /usr/bin/mc /usr/local/bin/mc
COPY --from=build /out /out
COPY --from=0 /x /x
FROM scratch
COPY --from=vendor/tool:latest /tool /tool
FROM golang:1.25-alpine AS go
`
	bases, copies := undeclaredFetches(recipe, map[string]bool{"RUNTIME_BASE": true})
	if strings.Join(copies, "|") != "${MC_BASE} (a build argument the manifest does not declare)|vendor/tool:latest" {
		t.Fatalf("copies out of undeclared images: %v", copies)
	}
	// A base fetched on its own is named apart, and refused like a copy (ADR 0097).
	if strings.Join(bases, "|") != "golang:1.25-alpine" {
		t.Fatalf("undeclared bases: %v", bases)
	}
	if _, copies := undeclaredFetches(recipe, map[string]bool{"RUNTIME_BASE": true, "MC_BASE": true}); len(copies) != 1 {
		t.Fatalf("declared arguments are not fetches: %v", copies)
	}
}

// Continued lines are one instruction, heredoc bodies are not instructions, and a RUN --mount reaches
// for an image as a COPY --from does (review C4, C5).
func TestARecipeIsReadAsInstructions(t *testing.T) {
	recipe := "ARG RUNTIME_BASE\n" +
		"FROM ${RUNTIME_BASE} \\\n  AS build\n" +
		"COPY \\\n  --from=docker.io/vendor/one:latest /a /a\n" +
		"COPY --from=build /out /out\n" +
		"COPY <<EOF /app/x.py\nfrom os import path\nEOF\n" +
		"RUN --mount=type=bind,from=docker.io/vendor/two:1,target=/t cp /t/x /x\n" +
		"FROM scratch\n"
	bases, copies := undeclaredFetches(recipe, map[string]bool{"RUNTIME_BASE": true})
	if strings.Join(copies, "|") != "docker.io/vendor/one:latest|docker.io/vendor/two:1" {
		t.Fatalf("copies: %v", copies)
	}
	if len(bases) != 0 {
		t.Fatalf("a heredoc line or a continued stage was read as a base: %v", bases)
	}
}

// What a build was handed as its bases is what it stood on — recorded, so a changed base knows what
// to rebuild (novox/hq 04-ISSUES/131). A recipe reads the base from an argument, so nothing else
// could know.
func TestTheBasesABuildWasHandedAreWhatItStoodOn(t *testing.T) {
	manifest := catalogue.Manifest{
		Module: "gitea",
		Build: &catalogue.Build{
			On: []catalogue.BuildsOn{
				{Arg: "RUNTIME_BASE", Module: "mesh-tools", Artifact: "runtime"},
				{Arg: "BUILD_BASE", Module: "mesh-tools", Artifact: "build"},
			},
			Artifacts: []catalogue.Artifact{{Name: "runtime", Kind: catalogue.ArtifactImage, From: "Dockerfile"}},
		},
	}
	held := map[string]string{
		"mesh-tools/runtime": "127.0.0.1:5000/mesh-tools/runtime@sha256:" + strings.Repeat("a", 64),
		"mesh-tools/build":   "127.0.0.1:5000/mesh-tools/build@sha256:" + strings.Repeat("b", 64),
	}
	_, resolved, err := standingOn(context.Background(), manifest, held, noMirror)
	if err != nil {
		t.Fatal(err)
	}
	got := against(t.TempDir(), manifest, resolved)
	if len(got) != 2 || got[0] != held["mesh-tools/build"] || got[1] != held["mesh-tools/runtime"] {
		t.Fatalf("the bases the build was handed were not what it stood on: %v", got)
	}
}

// What a build read besides its module's own repository is the second repository its recipes name,
// each once: a module that packages source living elsewhere is affected when that source moves.
func TestWhatABuildReadIsTheRepositoriesItsRecipesName(t *testing.T) {
	elsewhere := catalogue.ArtifactContext{Repository: "http://forge.internal:20000/novox/mesh-controller.git", Ref: "main"}
	manifest := catalogue.Manifest{
		Module: "builder",
		Build: &catalogue.Build{Artifacts: []catalogue.Artifact{
			{Name: "server", Kind: catalogue.ArtifactImage, From: "Dockerfile", Context: &elsewhere},
			{Name: "tools", Kind: catalogue.ArtifactImage, From: "Dockerfile", Context: &elsewhere},
			{Name: "config", Kind: catalogue.ArtifactArchive, From: "etc"},
		}},
	}
	read := readBy(manifest)
	if len(read) != 1 || read[0] != elsewhere {
		t.Fatalf("the repositories this build read are %+v", read)
	}
	if readBy(catalogue.Manifest{Module: "gitea", Build: &catalogue.Build{}}) != nil {
		t.Fatal("a module whose recipes name no other repository read one")
	}
}