package wasmguest

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"

	"connectrpc.com/connect"
	abiv1 "git.dev.alexdunmow.com/block/pluginsdk/abi/v1"
	"git.dev.alexdunmow.com/block/pluginsdk/blocks"
	"git.dev.alexdunmow.com/block/pluginsdk/plugin"
	"git.dev.alexdunmow.com/block/pluginsdk/plugin/wasmguest/caps"
	"git.dev.alexdunmow.com/block/pluginsdk/rbac"
	"github.com/google/uuid"
	"google.golang.org/protobuf/proto"
)

// AbiVersion is the ABI major version this guest shim implements
// (PluginManifest.abi_version). See core/docs/wasm-abi.md for the
// compatibility rules.
const AbiVersion uint32 = 1

// describe handles HOOK_DESCRIBE: validate the caller's ABI version and
// return the static PluginManifest. Publish-time only — never called on a
// live instance.
func (g *guest) describe(payload []byte) (proto.Message, *abiv1.AbiError) {
	req := &abiv1.DescribeRequest{}
	if err := proto.Unmarshal(payload, req); err != nil {
		return nil, decodeError("DescribeRequest", err)
	}
	// Symmetric version gate: a newer guest shim refuses a host it does not
	// support, mirroring the host's manifest rejection.
	if req.GetHostAbiVersion() != AbiVersion {
		return nil, &abiv1.AbiError{
			Code: abiv1.AbiErrorCode_ABI_ERROR_CODE_UNIMPLEMENTED,
			Message: fmt.Sprintf("guest implements ABI major version %d; host declared %d",
				AbiVersion, req.GetHostAbiVersion()),
		}
	}
	return &abiv1.DescribeResponse{Manifest: g.buildManifest()}, nil
}

// buildManifest assembles the PluginManifest from the registration's static
// funcs plus the Register captures. Field-by-field mapping:
// core/docs/wasm-abi.md §"Manifest ↔ PluginRegistration mapping".
func (g *guest) buildManifest() *abiv1.PluginManifest {
	reg := g.reg
	m := &abiv1.PluginManifest{
		AbiVersion:     AbiVersion,
		Name:           reg.Name,
		Version:        reg.Version,
		HasHttpHandler: reg.HTTPHandler != nil,
		HasLoadHook:    reg.Load != nil,
		HasUnloadHook:  reg.Unload != nil,
		HasMediaHooks:  reg.MediaHooks != nil,
		HasProvisioner: reg.RegisterWithProvisioner != nil,
	}

	for _, d := range reg.Dependencies {
		m.Dependencies = append(m.Dependencies, &abiv1.Dependency{
			Plugin: d.Plugin, MinVersion: d.MinVersion, Required: d.Required,
		})
	}

	// Register captures. BlockMeta.Source is omitted deliberately — the host
	// assigns it from the manifest name at load time.
	for _, meta := range g.blocks.metas {
		m.Blocks = append(m.Blocks, &abiv1.BlockMeta{
			Key:             meta.Key,
			Title:           meta.Title,
			Description:     meta.Description,
			Category:        string(meta.Category),
			HasInternalSlot: meta.HasInternalSlot,
			Hidden:          meta.Hidden,
			EditorJs:        meta.EditorJS,
		})
	}
	for _, o := range g.blocks.overrides {
		m.BlockTemplateOverrides = append(m.BlockTemplateOverrides, &abiv1.BlockTemplateOverride{
			TemplateKey: o.templateKey, BlockKey: o.blockKey, Source: o.source,
		})
	}
	m.TemplateKeys = append(m.TemplateKeys, g.templates.templateKeys...)
	for _, st := range g.templates.systemTemplates {
		m.SystemTemplates = append(m.SystemTemplates, &abiv1.SystemTemplateMeta{
			Key: st.Key, Title: st.Title, Description: st.Description,
		})
	}
	for _, pt := range g.templates.pageTemplates {
		m.PageTemplates = append(m.PageTemplates, &abiv1.PageTemplateMeta{
			SystemKey:   pt.systemKey,
			Key:         pt.meta.Key,
			Title:       pt.meta.Title,
			Description: pt.meta.Description,
			Slots:       pt.meta.Slots,
		})
	}
	seenWrapper := make(map[string]bool)
	for _, ew := range g.templates.emailWrappers {
		if !seenWrapper[ew.systemKey] {
			seenWrapper[ew.systemKey] = true
			m.EmailWrapperSystemKeys = append(m.EmailWrapperSystemKeys, ew.systemKey)
		}
	}

	// Static funcs.
	if reg.AdminPages != nil {
		for _, p := range reg.AdminPages() {
			m.AdminPages = append(m.AdminPages, &abiv1.AdminPage{
				Key: p.Key, Title: p.Title, Icon: p.Icon, Route: p.Route,
			})
		}
	}
	if reg.SettingsSchema != nil {
		m.SettingsSchema = reg.SettingsSchema()
	}
	if reg.ThemePresets != nil {
		m.ThemePresets = reg.ThemePresets()
	}
	if reg.BundledFonts != nil {
		m.BundledFonts = reg.BundledFonts()
	}
	if reg.MasterPages != nil {
		for _, mp := range reg.MasterPages() {
			m.MasterPages = append(m.MasterPages, masterPageToProto(mp))
		}
	}
	if reg.AIActions != nil {
		for _, a := range reg.AIActions() {
			m.AiActions = append(m.AiActions, &abiv1.AiAction{
				Key:             a.Key,
				Title:           a.Title,
				Description:     a.Description,
				DefaultProvider: a.DefaultProvider,
				DefaultModel:    a.DefaultModel,
			})
		}
	}
	if reg.CSSManifest != nil {
		if cm := reg.CSSManifest(); cm != nil {
			m.CssManifest = &abiv1.CssManifest{
				NpmPackages:    cm.NPMPackages,
				CssDirectives:  cm.CSSDirectives,
				InputCssAppend: cm.InputCSSAppend,
			}
		}
	}
	m.RequiredIconPacks = append(m.RequiredIconPacks, reg.RequiredIconPacks...)

	// Custom template tags/filters the plugin registered via blocks.RegisterTag
	// / blocks.RegisterFilter during the Register pass (runRegister reset the
	// registry first, so these reflect exactly this plugin). The host wires a
	// pongo2 tag/filter per name that calls back via HOOK_RENDER_TAG /
	// HOOK_APPLY_FILTER.
	m.DeclaredTags = blocks.RegisteredTagNames()
	m.DeclaredFilters = blocks.RegisteredFilterNames()
	if reg.DirectoryExtensions != nil {
		if de := reg.DirectoryExtensions(); de != nil {
			pde := &abiv1.DirectoryExtensions{
				BooleanFilterFields: de.BooleanFilterFields,
				SelectFilterFields:  de.SelectFilterFields,
				PanelSectionCount:   uint32(len(de.PanelSections)),
				PinDecoratorCount:   uint32(len(de.PinDecorators)),
			}
			if len(de.BadgeLabels) > 0 {
				pde.BadgeLabels = make(map[string]*abiv1.BadgeLabel, len(de.BadgeLabels))
				for k, v := range de.BadgeLabels {
					pde.BadgeLabels[k] = &abiv1.BadgeLabel{Positive: v[0], Negative: v[1]}
				}
			}
			m.DirectoryExtensions = pde
		}
	}
	if reg.SettingsPanel != nil {
		m.SettingsPanel = reg.SettingsPanel()
	}

	// Function fields probed with capture-only CoreServices. These calls run
	// without a live host, so panics from touching unwired capabilities are
	// swallowed — whatever was declared before the panic is still captured.
	m.JobTypes = g.captureJobTypes()
	m.RagContentFetcherTypes = g.captureRagFetcherTypes()
	g.captureServiceRegistration(m)

	return m
}

// captureJobTypes enumerates JobHandlers keys with describe-time services.
func (g *guest) captureJobTypes() (types []string) {
	if g.reg.JobHandlers == nil {
		return nil
	}
	defer func() { recover() }() //nolint:errcheck // publish-time probe; partial capture is intended
	handlers := g.reg.JobHandlers(describeServices())
	types = sortedKeys(handlers)
	return types
}

// captureRagFetcherTypes runs Load against capture-only services to record
// RAGService.RegisterContentFetcher declarations. DESCRIBE is publish-time
// only, so Load's runtime side effects have no host to land on; a panic
// (e.g. from an unwired capability) ends the probe but keeps prior
// registrations.
func (g *guest) captureRagFetcherTypes() (types []string) {
	if g.reg.Load == nil {
		return nil
	}
	rag := caps.NewRAGStub(nil)
	svcs := describeServices()
	svcs.RAGService = rag
	func() {
		defer func() { recover() }() //nolint:errcheck // publish-time probe
		_ = g.reg.Load(svcs)
	}()
	return rag.FetcherTypes()
}

// captureServiceRegistration probes ServiceHandlers to record RBAC method
// roles and CoreServiceBindings.Bind declarations.
func (g *guest) captureServiceRegistration(m *abiv1.PluginManifest) {
	if g.reg.ServiceHandlers == nil {
		return
	}
	bindings := &captureCoreServiceBindings{}
	svcs := describeServices()
	svcs.CoreServiceBindings = bindings

	var sr *plugin.ServiceRegistration
	func() {
		defer func() { recover() }() //nolint:errcheck // publish-time probe
		reg, err := g.reg.ServiceHandlers(svcs)
		if err == nil {
			sr = reg
		}
	}()

	m.CoreServiceBindings = append(m.CoreServiceBindings, bindings.bound...)
	if sr == nil {
		return
	}
	coreBound := make(map[string]bool, len(bindings.bound))
	for _, b := range bindings.bound {
		coreBound[b.GetServiceName()] = true
	}
	for _, svc := range sr.Services {
		if coreBound[svc.Name()] {
			continue // declared via core_service_bindings, host mounts it
		}
		for method, role := range svc.MethodRoles() {
			if m.RbacMethodRoles == nil {
				m.RbacMethodRoles = make(map[string]string)
			}
			m.RbacMethodRoles[method] = string(role)
		}
	}
}

// describeServices returns the CoreServices value used to probe registration
// funcs at publish time. It uses the capability stubs with a nil transport:
// there is no live host during DESCRIBE, so any capability a plugin invokes
// returns a clean "no host transport" error instead of nil-panicking, letting
// the probe capture whatever static registrations (jobs, RAG fetchers)
// surround the call. Callers still recover, belt-and-suspenders.
func describeServices() plugin.CoreServices {
	return caps.NewCoreServices(nil)
}

func masterPageToProto(mp plugin.MasterPageDefinition) *abiv1.MasterPageDefinition {
	out := &abiv1.MasterPageDefinition{
		Key:           mp.Key,
		Title:         mp.Title,
		PageTemplates: mp.PageTemplates,
	}
	for _, b := range mp.Blocks {
		pb := &abiv1.MasterPageBlock{
			BlockKey:    b.BlockKey,
			Title:       b.Title,
			Slot:        b.Slot,
			SortOrder:   b.SortOrder,
			HtmlContent: b.HtmlContent,
		}
		if b.Content != nil {
			if raw, err := json.Marshal(b.Content); err == nil {
				pb.ContentJson = raw
			}
		}
		out.Blocks = append(out.Blocks, pb)
	}
	return out
}

// --- capture / no-op stubs used only during DESCRIBE probes ---

type captureCoreServiceBindings struct {
	bound []*abiv1.CoreServiceBinding
}

func (c *captureCoreServiceBindings) Bind(serviceName string, methodRoles map[string]rbac.Role) (plugin.ConnectServiceBinding, error) {
	roles := make(map[string]string, len(methodRoles))
	for k, v := range methodRoles {
		roles[k] = string(v)
	}
	c.bound = append(c.bound, &abiv1.CoreServiceBinding{ServiceName: serviceName, MethodRoles: roles})
	return plugin.NewConnectServiceBinding(serviceName, struct{}{},
		func(_ struct{}, _ ...connect.HandlerOption) (string, http.Handler) {
			return "/" + serviceName + "/", http.NotFoundHandler()
		}, methodRoles), nil
}

// noopProvisioner satisfies plugin.Provisioner for the DESCRIBE-time
// Register pass; real provisioning runs host-side at load.
type noopProvisioner struct{}

func (noopProvisioner) EnsureDataTable(plugin.DataTableConfig) error       { return nil }
func (noopProvisioner) MergeSiteSettings(map[string]any) error             { return nil }
func (noopProvisioner) EnsureSetting(string, any) error                    { return nil }
func (noopProvisioner) EnsurePage(plugin.PageConfig) error                 { return nil }
func (noopProvisioner) OverrideSiteSettings(map[string]any) error          { return nil }
func (noopProvisioner) EnsureMenuItem(string, plugin.MenuItemConfig) error { return nil }
func (noopProvisioner) RegisterEmbeddingConfig(plugin.EmbeddingConfigDef) error {
	return nil
}
func (noopProvisioner) EnsureEmbed(plugin.EmbedConfig) error             { return nil }
func (noopProvisioner) EnsureJobSchedule(plugin.JobScheduleConfig) error { return nil }
func (noopProvisioner) UpdateDataTableRowField(context.Context, uuid.UUID, string, any) error {
	return nil
}
func (noopProvisioner) DisableOrphanedJobSchedules([]string) error       { return nil }
func (noopProvisioner) EnsurePlugin(string) error                        { return nil }
func (noopProvisioner) EnsureCustomColor(plugin.CustomColorConfig) error { return nil }
func (noopProvisioner) EnsureMedia(plugin.MediaDeposit) error            { return nil }