mesh-delivery/modules/mesh-delivery-indexer/internal/index/validate.go

package index

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"maps"
	"slices"
	"strings"

	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-contracts/go/seats/meshcatalog"
	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-sdk/buildstep"
	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-sdk/composer"
	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-sdk/trunk"
	"git.novox.be/novox/mesh-sdk/go/catalogue"

	"mesh-delivery-indexer/judge"
)

// The validation before take-in (design 47 G §712, A-213, A-232): for a pending revision of a watched branch the running
// indexer asks the seat node-build-go a `run` of its own manifest validator over two cases, change and trunk, and refuses only
// what the revision causes (ADR 0579 §2). The ask rides the check queue under the indexer's name, its kind `run` in the body.
const (
	// validationProgram is the manifest validator's program, by its directory under the indexer entry's Go module: the indexer's
	// own code, so no repository or module name is fixed here (ADR 0666 §5).
	validationProgram = "cmd/mesh-judge"
	// ValidationAsker is the asker the ask is put under (buildrun.Asker.Name, A-248). A-232 names the indexer's seat name mesh-catalog; the ask code still
	// names askers by their nicknames until the asker rename after the join (A-163), so this is `indexer` until then.
	ValidationAsker = "indexer"
	// validationCatalogSeat is the seat the indexer entry claims.
	validationCatalogSeat = "mesh-catalog"
	// The cases of the request, as the manifest validator names them.
	validationChange = "change"
	validationTrunk  = judge.TrunkCase
)

// validationInputVerb is where the build seat's holder asks the input: the seat mesh-catalog's verb input (§354).
var validationInputVerb = "seat:" + meshcatalog.Seat + "." + meshcatalog.VerbInput

// validationRequest is the manifest validator's request for the ready merges of branch over the branch's current revision
// (§712): case change, every module of the revision by its entry's manifest, each one the merges carry replaced by the merged
// message's bytes (the newest merge governs) and one added for a new directory; case trunk, every module as it stands; the
// seat definitions the merges' trees carry; the packages and the predefined list as the take-in's own validator has them;
// no machines. It answers the indexer entry of the change case too, the one that claims the seat mesh-catalog.
func (ix *Indexer) validationRequest(ctx context.Context, branch string, ready []PendingEntry) (composer.Request, meshcatalog.CatalogEntry, error) {
	var indexer meshcatalog.CatalogEntry
	if ix.Revisions == nil {
		return composer.Request{}, indexer, errors.New("the catalog graph is not kept here: no revision to validate over")
	}
	rev, found, err := newestOf(ctx, ix.Revisions, branch)
	if err != nil {
		return composer.Request{}, indexer, err
	}
	var entries []meshcatalog.CatalogEntry
	if found {
		if _, entries, err = ReadRevision(ctx, ix.Revisions, RevisionObject(rev)); err != nil {
			return composer.Request{}, indexer, err
		}
	}
	trunkCase := composer.Case{Name: validationTrunk, Manifests: map[string]composer.Manifest{}}
	byPlace := map[string]string{} // <repository> <path> -> module
	of := map[string]meshcatalog.CatalogEntry{}
	for _, e := range entries {
		raw := ix.manifestBytes(ctx, e.ManifestDigest)
		if raw == "" {
			b, err := json.Marshal(e.Manifest)
			if err != nil {
				return composer.Request{}, indexer, fmt.Errorf("the manifest of %s: %w", e.Module, err)
			}
			raw = string(b)
		}
		trunkCase.Manifests[e.Module] = composer.Manifest{Raw: json.RawMessage(raw)}
		byPlace[placeKey(e.Repository, e.Path)] = e.Module
		of[e.Module] = e
	}
	change := composer.Case{Name: validationChange, Manifests: maps.Clone(trunkCase.Manifests)}
	for _, e := range ready {
		if e.Covered {
			continue
		}
		for _, dir := range slices.Sorted(maps.Keys(e.Forge.Manifests)) {
			raw := e.Forge.Manifests[dir]
			module, known := byPlace[placeKey(e.Forge.Repository, dir)]
			if !known {
				m, err := judge.ForInputs([]byte(raw))
				if err != nil || m.Module == "" {
					module = e.Forge.Repository + "/" + dir // a new directory whose manifest names no module: judged under its place
				} else {
					module = m.Module
				}
				byPlace[placeKey(e.Forge.Repository, dir)] = module
				of[module] = meshcatalog.CatalogEntry{Module: module, Repository: e.Forge.Repository, Path: dir}
			}
			change.Manifests[module] = composer.Manifest{Raw: json.RawMessage(raw)}
		}
	}
	for _, module := range slices.Sorted(maps.Keys(change.Manifests)) {
		m, err := judge.ForInputs(change.Manifests[module].Raw)
		if err != nil || !slices.ContainsFunc(m.Claims, func(c catalogue.Claim) bool { return c.Name == validationCatalogSeat }) {
			continue
		}
		indexer = of[module]
		if indexer.Module == "" {
			indexer.Module = module
		}
		break
	}
	seats, err := ix.revisionDefinitions(ctx, ready)
	if err != nil {
		return composer.Request{}, indexer, err
	}
	req := composer.Request{V: composer.Version, Input: json.RawMessage("{}"), Cases: []composer.Case{change, trunkCase}, Seats: seats,
		Predefined: ix.predefinedList(ctx)}
	if known := ix.knownPackages(ctx); known != nil {
		req.Packages = slices.Sorted(maps.Keys(known))
	}
	return req, indexer, nil
}

func placeKey(repository, path string) string {
	return strings.ToLower(trunk.RepositoryName(repository)) + " " + path
}

// revisionDefinitions are the validation's seat definitions, raw (§712 `seats`, A-241): the branch's revision's seat
// definitions with the definitions the merges' trees carry laid over them, so a revision that touches no definition is still
// judged against the whole seat list. A revision's own definitions are not kept yet (A-234), so the revision's are the
// trunk's, read from the state seat-definitions as the verb seat-definitions answers them.
func (ix *Indexer) revisionDefinitions(ctx context.Context, ready []PendingEntry) ([]json.RawMessage, error) {
	defs, err := ix.trunkDefinitions(ctx)
	if err != nil {
		return nil, err
	}
	merged, err := ix.revisionSeatDefinitions(ctx, ready)
	if err != nil {
		return nil, err
	}
	for seat, d := range merged {
		raw, err := json.Marshal(d)
		if err != nil {
			return nil, fmt.Errorf("the definition of %s: %w", seat, err)
		}
		defs[seat] = raw
	}
	var out []json.RawMessage
	for _, seat := range slices.Sorted(maps.Keys(defs)) {
		out = append(out, defs[seat])
	}
	return out, nil
}

// trunkDefinitions are the trunk's seat definitions of the state seat-definitions, raw, by seat: every `<seat>.trunk` entry
// that holds a definition; none where the indexer keeps no such state.
func (ix *Indexer) trunkDefinitions(ctx context.Context) (map[string]json.RawMessage, error) {
	defs := map[string]json.RawMessage{}
	if ix.SeatDefinitions == nil {
		return defs, nil
	}
	keys, err := ix.SeatDefinitions.Keys(ctx)
	if err != nil {
		return nil, fmt.Errorf("the %s state cannot be listed: %w", SeatDefinitionsState, err)
	}
	for _, key := range keys {
		seat, ok := strings.CutSuffix(key, "."+SourceTrunk)
		if !ok || strings.HasPrefix(key, outOfStepPrefix) {
			continue
		}
		v, _, found, err := ix.SeatDefinitions.Get(ctx, key)
		if err != nil {
			return nil, fmt.Errorf("%s.%s cannot be read: %w", SeatDefinitionsState, key, err)
		}
		var e SeatDefinitionEntry
		if !found || json.Unmarshal(v, &e) != nil || e.Digest == "" || len(e.Definition) == 0 {
			continue // an entry that holds no definition is no seat of the list
		}
		defs[seat] = e.Definition
	}
	return defs, nil
}

// validationJob is the run of the manifest validator for the request (§712): the program cmd/mesh-judge, its directory under
// the Go module the go.mod at the entry's path names (read by the build, A-268), at the entry's path, built at head, the revision's head of the entry's repository; no
// heads and no arguments; the input the request's bytes, served by the seat mesh-catalog's verb input.
func validationJob(indexer meshcatalog.CatalogEntry, head, branch string, seq uint64, input []byte) (buildstep.RunJob, error) {
	switch {
	case indexer.Repository == "":
		return buildstep.RunJob{}, fmt.Errorf("no entry of the revision claims the seat %s", validationCatalogSeat)
	case head == "":
		return buildstep.RunJob{}, fmt.Errorf("the revision names no head of %s, the repository of the indexer entry %s", indexer.Repository, indexer.Module)
	}
	in, err := buildstep.RunInputOf(validationInputVerb, input)
	if err != nil {
		return buildstep.RunJob{}, err
	}
	dir := indexer.Path
	if dir == "" {
		dir = "."
	}
	return buildstep.RunJob{
		Program: buildstep.RunProgram{Repository: indexer.Repository, Commit: head, Dir: dir, Package: "./" + validationProgram},
		Input:   in,
		Reader:  fmt.Sprintf("manifest validator of %s at %d", branchName(branch), seq),
	}, nil
}

func branchName(branch string) string {
	if isTrunkBranch(branch) {
		return TrunkBranch
	}
	return branch
}

// ValidationRefusal is what a validation's verdict refuses (ADR 0579 §2, §712): of each manifest the change case refuses that
// the revision adds or changes (its bytes differ from the trunk case's), each problem the trunk case lacks; and each problem
// between manifests the trunk case lacks. A problem only in unchanged manifests refuses nothing. It is empty when the revision
// is accepted. An answer that holds not both cases is no verdict: it answers an error, so the run could not validate.
func ValidationRefusal(req composer.Request, v composer.Verdict) (map[string][]string, error) {
	cases := map[string]composer.CaseVerdict{}
	for _, c := range v.Cases {
		cases[c.Name] = c
	}
	change, okChange := cases[validationChange]
	trunkV, okTrunk := cases[validationTrunk]
	if !okChange || !okTrunk {
		return nil, fmt.Errorf("the manifest validator's answer holds not both cases %s and %s", validationChange, validationTrunk)
	}
	raws := map[string]map[string]string{}
	for _, c := range req.Cases {
		raws[c.Name] = map[string]string{}
		for name, m := range c.Manifests {
			raws[c.Name][name] = InputDigest(m.Raw)
		}
	}
	refused := map[string][]string{}
	for _, module := range slices.Sorted(maps.Keys(change.Manifests)) {
		r := change.Manifests[module]
		if r.Accepted || r.Refused == "" {
			continue
		}
		before, had := raws[validationTrunk][module]
		if module != judge.Unnamed && had && before == raws[validationChange][module] {
			continue // unchanged: its problems refuse nothing, and its entry keeps its verdict (ADR 0579 §1)
		}
		old := map[string]bool{}
		for _, p := range strings.Split(trunkV.Manifests[module].Refused, "\n") {
			old[p] = true
		}
		for _, p := range strings.Split(r.Refused, "\n") {
			if p != "" && !old[p] {
				refused[module] = append(refused[module], p)
			}
		}
	}
	return refused, nil
}

// RefusedWords is a refusal as the pending value's `refused` says it: each manifest and its problems, one manifest a line.
func RefusedWords(refused map[string][]string) string {
	var lines []string
	for _, module := range slices.Sorted(maps.Keys(refused)) {
		lines = append(lines, module+": "+strings.Join(refused[module], "; "))
	}
	return strings.Join(lines, "\n")
}