package wasmguest

import (
	"io/fs"

	"git.dev.alexdunmow.com/block/pluginsdk/blocks"
	"git.dev.alexdunmow.com/block/pluginsdk/templates"
)

// captureBlockRegistry implements blocks.BlockRegistry by recording every
// registration instead of wiring it into a live host. It backs both DESCRIBE
// (metadata enumeration) and runtime dispatch (BlockFunc lookup).
//
// It is always used behind plugin.NewPluginBlockRegistry, so keys arrive
// already plugin-prefixed and overrides arrive with their source set —
// identical to what a plugin sees in the .so world.
type captureBlockRegistry struct {
	metas     []blocks.BlockMeta
	funcs     map[string]blocks.BlockFunc // block key → fn
	overrides []blockOverride
}

type blockOverride struct {
	templateKey string
	blockKey    string
	source      string
	fn          blocks.BlockFunc
}

func newCaptureBlockRegistry() *captureBlockRegistry {
	return &captureBlockRegistry{funcs: make(map[string]blocks.BlockFunc)}
}

func (r *captureBlockRegistry) Register(meta blocks.BlockMeta, fn blocks.BlockFunc) {
	r.metas = append(r.metas, meta)
	r.funcs[meta.Key] = fn
}

func (r *captureBlockRegistry) RegisterTemplateOverride(templateKey, blockKey string, fn blocks.BlockFunc) {
	r.overrides = append(r.overrides, blockOverride{templateKey: templateKey, blockKey: blockKey, fn: fn})
}

func (r *captureBlockRegistry) RegisterTemplateOverrideWithSource(templateKey, blockKey, source string, fn blocks.BlockFunc) {
	r.overrides = append(r.overrides, blockOverride{templateKey: templateKey, blockKey: blockKey, source: source, fn: fn})
}

// LoadSchemasFromFS is a no-op in the wasm guest: block schemas ship in the
// .bnp artifact's schemas/ directory and are loaded host-side.
func (r *captureBlockRegistry) LoadSchemasFromFS(fs.FS) error { return nil }

func (r *captureBlockRegistry) LoadSchemasFromFSWithPrefix(fs.FS, string) error { return nil }

// lookup resolves a block function for dispatch: a template-scoped override
// wins over the base registration, mirroring the host registry's behavior.
func (r *captureBlockRegistry) lookup(blockKey, templateKey string) (blocks.BlockFunc, bool) {
	if templateKey != "" {
		for _, o := range r.overrides {
			if o.templateKey == templateKey && o.blockKey == blockKey {
				return o.fn, true
			}
		}
	}
	fn, ok := r.funcs[blockKey]
	return fn, ok
}

// captureTemplateRegistry implements templates.TemplateRegistry by recording
// registrations for DESCRIBE and runtime dispatch.
type captureTemplateRegistry struct {
	templateKeys    []string // insertion order of Register calls
	funcs           map[string]templates.TemplateFunc
	systemTemplates []templates.SystemTemplateMeta
	pageTemplates   []capturedPageTemplate
	emailWrappers   []capturedEmailWrapper
}

type capturedPageTemplate struct {
	systemKey string
	meta      templates.PageTemplateMeta
}

type capturedEmailWrapper struct {
	systemKey string
	fn        templates.EmailWrapperFunc
}

func newCaptureTemplateRegistry() *captureTemplateRegistry {
	return &captureTemplateRegistry{funcs: make(map[string]templates.TemplateFunc)}
}

func (r *captureTemplateRegistry) Register(key string, fn templates.TemplateFunc) error {
	r.templateKeys = append(r.templateKeys, key)
	r.funcs[key] = fn
	return nil
}

func (r *captureTemplateRegistry) RegisterSystemTemplate(meta templates.SystemTemplateMeta) {
	r.systemTemplates = append(r.systemTemplates, meta)
}

func (r *captureTemplateRegistry) RegisterPageTemplate(systemKey string, meta templates.PageTemplateMeta, fn templates.TemplateFunc) error {
	r.pageTemplates = append(r.pageTemplates, capturedPageTemplate{systemKey: systemKey, meta: meta})
	r.funcs[meta.Key] = fn
	return nil
}

func (r *captureTemplateRegistry) RegisterEmailWrapper(systemKey string, fn templates.EmailWrapperFunc) {
	r.emailWrappers = append(r.emailWrappers, capturedEmailWrapper{systemKey: systemKey, fn: fn})
}

func (r *captureTemplateRegistry) lookup(key string) (templates.TemplateFunc, bool) {
	fn, ok := r.funcs[key]
	return fn, ok
}