package catalogue

import (
	"encoding/json"
	"errors"
	"fmt"
	"strings"
)

// Handed is what a moved module's build kept for the provisioner (novox/hq ADR 0349 §2): its templates archive, as
// recorded (store-relative, routed at composition like any archive), and its digest; and, for each file resource
// filled from a template, that template's path inside the archive. Written by Resolve, never by hand.
type Handed struct {
	Source    string            `json:"source"`
	Digest    string            `json:"digest"`
	Templates map[string]string `json:"templates"`
	// Items is, for each item the module contributes, by ItemKey (its collection, and `/<name>` for a named one),
	// that item's template inside the archive (collections.go, design 57 L1).
	Items map[string]string `json:"items,omitempty"`
}

// Plan is a moved module's plan on one node: what the node's provisioner client fills its files from. The shape
// of the assignments mirror's `provisioning` (mesh-controller internal/inventory Provisioning).
type Plan struct {
	Templates PlanTemplates     `json:"templates"`
	Files     []PlanFile        `json:"files"`
	Placement map[string]string `json:"placement,omitempty"`
	// Secrets are the module's own secrets this declaration names (design 57 V4, issue 647): each its templates
	// name, and each it keeps in a file of its own, with that file's path. By name, never a value: the client asks
	// the vault for each, and the vault hands one only when the plan names it.
	Secrets []PlanSecret `json:"secrets,omitempty"`
	// Items are the module's items of collections (design 57 L1): each filled by the client like a file and recorded
	// in mesh-provisioner_collect for its node. Collections are the collections its files name, as their collector,
	// each with its comment. By template and name, never a contributor's text.
	Items       []PlanItem       `json:"items,omitempty"`
	Collections []PlanCollection `json:"collections,omitempty"`
	// Provisions are what it requires here, each with the provider resolution chose to serve it (issue 760), so the
	// vault sees a consumer bind to a provider and unbind from it (novox/hq ADR 0349 clause 8); and, for a
	// credential the vault keeps for it alone, the name its files call it and the file holding it (issue 757). By
	// name, never a value.
	Provisions []PlanProvision `json:"provisions,omitempty"`
}

// Hands is whether the plan hands its module to the provisioner: it names something the node's provisioner client fills
// (a template archive, a file, an own secret or an item), and the node composes none of it. A plan naming provisions alone
// hands nothing (catalogue.Keyed, issue 774): the seat keys what a provider's helper answers of a module not handed, and
// that module's files and own secrets stay its node's composition. The one rule every reader of a plan asks; whether a
// plan exists is never it (on 2026-10-30 the vault read every route-only plan as handed and answered twenty modules'
// own secrets to nobody).
func (p Plan) Hands() bool {
	return p.Templates.Source != "" || len(p.Files) > 0 || len(p.Secrets) > 0 || len(p.Items) > 0
}

// PlanItem is one item the module contributes: to which collection, and its template inside the archive.
//
// A named item has its Name and Attributes (design 57 L3, issue 777): the client records them with the item and
// places it under a placeholder selecting by them. An item whose `if-capability` the machine lacks is not in the plan.
type PlanItem struct {
	Collection string            `json:"collection"`
	Name       string            `json:"name,omitempty"`
	Attributes map[string]string `json:"attributes,omitempty"`
	Template   string            `json:"template"`
}

// PlanCollection is one collection the module collects, and the comment introducing each contributor's item.
type PlanCollection struct {
	Name    string `json:"name"`
	Comment string `json:"comment,omitempty"`
}

// PlanProvision is one provision the module requires, under one local name, and the provider serving it: the module
// (ProviderModule) on the machine (Provider) that resolution chose for this consumer. Where several providers offer
// a mesh-scoped provision, it is the one this consumer is bound to (a pin, the seat's holder, or where its data is),
// never the others (issue 760). Local is the name the consumer keeps the credential under where it keeps several
// from one requirement (ADR 0094), empty for the ordinary one; a consumer has one provider per provision and local
// name.
//
// Name and Path are set only for a credential the vault keeps for this holder alone, which its machine's client
// fills (issue 757): the value the provider's software issued for this module on this machine. Name is what the
// module's files call it (`${secret:<name>}`) and Path the file holding it alone.
//
// CredentialForm is the form the provider's offer declares for its credential (Manifest.CredentialFormOf, issue
// 768): the vault makes a first value in that form for a provider it holds no row of. Empty where the provider's
// manifest was not in hand, and the vault then makes nothing.
type PlanProvision struct {
	Name           string `json:"name,omitempty"`
	Provision      string `json:"provision"`
	Local          string `json:"local,omitempty"`
	Provider       string `json:"provider"`
	ProviderModule string `json:"provider-module"`
	CredentialForm string `json:"credential-form,omitempty"`
	// CredentialTool is, for an offer whose credential the provider's software issues (issue 928), the provider's tool
	// the vault asks for each holder's value; empty for any other form.
	CredentialTool string `json:"credential-tool,omitempty"`
	Path           string `json:"path,omitempty"`
	// Contributes is what the consumer's manifest tells its provider for this provision (Manifest.Contributes: a
	// database's name, its extensions), so the provider's helper learns it from the bus (issue 776). Nil where the
	// manifest contributes nothing for it, and the entry is then as it was.
	Contributes map[string]any `json:"contributes,omitempty"`
	// At, From and As are what today's binding file tells the consumer of this provision (issue 788): where the
	// provider is on the private network, the machine, and who the consumer is at its end (its slug first), so the
	// provider's helper writes them into the consumer's entry and the client fills `${bound:<provision>:at|from|as}`
	// from there. Empty where the resolution knew none.
	At   string `json:"at,omitempty"`
	From string `json:"from,omitempty"`
	As   string `json:"as,omitempty"`
	// Names are what the mesh calls the consumer through this provision (issue 792), keyed as its binding file names
	// them (`name`, `internal-name`, `name-<local>`, `internal-name-<local>`): composed by the controller, which
	// alone knows the node's domains, and carried unchanged by the provider's helper into the consumer's entry. Nil
	// where the consumer contributes nothing to the provision, and the entry is then as it was.
	Names map[string]string `json:"names,omitempty"`
	// Contributed is what the consumer gives its provider through this provision, opaque here (issue 774, research
	// 072 row 34): the bytes of a ContributedForm, each contribution composed as its provider receives it and where
	// the consumer's machine is. What a contribution's values mean is the provider's own contract, published by the
	// provider's repository (route-proxy's for a route), which decodes them; the seat, its plans, its client and the
	// helper carry them unread. On the provision's first entry alone; nil where the consumer contributes nothing to it.
	Contributed json.RawMessage `json:"contributed,omitempty"`
}

// ContributedVersion is the version of ContributedForm this SDK writes and reads.
const ContributedVersion = 1

// ContributedForm is the generic form of PlanProvision.Contributed: every contribution one consumer makes to one
// requirement, composed (settled with its node's settings, its endpoint's port filled in, its names joined to the
// node's domains: Resolution.composed, the one composition a received file was written from), and At, where the
// consumer's machine is on the private network, empty when it is on none. The provisioner knows no field of any
// contribution: Values are the bytes of an object in the provider's contract.
type ContributedForm struct {
	V    int              `json:"v"`
	At   string           `json:"at,omitempty"`
	Each []ContributedOne `json:"each"`
}

// ContributedOne is one contribution: Local its local name among several (`contributes` naming several), empty for a
// requirement's one, and Values the contribution's object.
type ContributedOne struct {
	Local  string          `json:"local,omitempty"`
	Values json.RawMessage `json:"values"`
}

// DecodeContributed reads PlanProvision.Contributed strictly: this version, no field it does not know, at least one
// contribution, each local name once, each value a JSON object. What a value says is not judged here.
func DecodeContributed(raw json.RawMessage) (ContributedForm, error) {
	var f ContributedForm
	dec := json.NewDecoder(strings.NewReader(string(raw)))
	dec.DisallowUnknownFields()
	if err := dec.Decode(&f); err != nil {
		return ContributedForm{}, fmt.Errorf("what a consumer contributed is not readable: %w", err)
	}
	if dec.More() {
		return ContributedForm{}, errors.New("what a consumer contributed carries more than one document")
	}
	if f.V != ContributedVersion {
		return ContributedForm{}, fmt.Errorf("what a consumer contributed is of version %d, this SDK reads %d", f.V,
			ContributedVersion)
	}
	if len(f.Each) == 0 {
		return ContributedForm{}, errors.New("what a consumer contributed holds no contribution")
	}
	seen := map[string]bool{}
	for _, one := range f.Each {
		if seen[one.Local] {
			return ContributedForm{}, fmt.Errorf("what a consumer contributed names %q twice", one.Local)
		}
		seen[one.Local] = true
		var object map[string]json.RawMessage
		if err := json.Unmarshal(one.Values, &object); err != nil || object == nil {
			return ContributedForm{}, fmt.Errorf("the contribution %q is not a JSON object", one.Local)
		}
	}
	return f, nil
}

// PlanSecret is one of the module's own secrets, by its name in the manifest; Path is the file holding it alone,
// when the manifest's own-secrets places one.
type PlanSecret struct {
	Name string `json:"name"`
	Path string `json:"path,omitempty"`
}

// PlanTemplates is where the templates archive is fetched from on this node, and what it hashes to.
type PlanTemplates struct {
	Source string `json:"source"`
	Digest string `json:"digest"`
}

// PlanFile is one file the client fills.
type PlanFile struct {
	ID             string `json:"id"`
	Path           string `json:"path"`
	Template       string `json:"template"`
	OwnerAtRuntime string `json:"owner-at-runtime"`
	Takes          string `json:"takes,omitempty"`
}

// The words a placed file says who owns it at runtime with (novox/hq ADR 0349 §5).
const (
	RuntimeOwned   = "owned"
	RuntimeSeed    = "seed"
	RuntimeManaged = "managed"
)

// OwnerAtRuntimeField is the key a declared file says who owns it at runtime by (the node-engine's
// `owner-at-runtime`).
const OwnerAtRuntimeField = "owner-at-runtime"

// handedBy is what a moved module's build keeps, from its templates archive as built, or nil for a module not
// moved.
func handedBy(m Manifest, archive Built) *Handed {
	if !m.Moved {
		return nil
	}
	dir := m.TemplatesDir()
	h := &Handed{Source: Recorded(archive.Reference), Digest: archive.Digest, Templates: map[string]string{}}
	for _, r := range m.Resources {
		name, has, wrong := templateOf(m.Module, dir, r)
		if !has || wrong != "" {
			continue
		}
		h.Templates[fmt.Sprint(r["id"])] = strings.TrimPrefix(name, dir+"/")
	}
	for _, it := range m.Items {
		if it.Template == "" || itemTemplateProblem(m, it.Template) != "" {
			continue
		}
		if h.Items == nil {
			h.Items = map[string]string{}
		}
		h.Items[it.key()] = strings.TrimPrefix(it.Template, dir+"/")
	}
	return h
}

// AssignmentHands is whether a module's value in the seat mesh-provisioner's plans (the assignments mirror's shape,
// `{"provisioning": <Plan>}`) hands its module to the provisioner: Plan.Hands of the plan it carries, false with no
// plan. A value that does not read is an error, never "not handed". The one rule the vault judges `own` by and a node
// composing itself follows (Rendering.Assigned, issue 774).
func AssignmentHands(raw []byte) (bool, error) {
	var a struct {
		Provisioning *Plan `json:"provisioning"`
	}
	if err := json.Unmarshal(raw, &a); err != nil {
		return false, err
	}
	return a.Provisioning != nil && a.Provisioning.Hands(), nil
}

// HandedProvisionField marks, between composing a handed module's credential file for something it requires and
// placing it, one the vault keeps for this holder alone (issue 757): its value is the PlanProvision without its path.
// Never on the wire.
const HandedProvisionField = "handed-provision"

// HandedSecretField marks, between composing a module's own secret files and placing them, the one a handing
// composition hands to the provisioner: its value is the secret's name. Never on the wire.
const HandedSecretField = "handed-secret"

// SettingField is the settings form's word for a config placeholder's namespace.
const SettingField = "setting"

// PlacementKinds are the placeholder namespaces placement answers (ADR 0349 clause 2), as a plan's keys begin.
var PlacementKinds = []string{"dir", "access", "port", "seat", "machine", BackupNamespace}