package pipeline

import (
	"fmt"
	"strings"

	"evobgp/internal/birdfmt"
	"evobgp/internal/store"
)

// BirdLocalsForSpeaker merges tenant settings with per-speaker meta_json overrides.
func BirdLocalsForSpeaker(st store.Backend, tenantID, speakerID string) birdLocals {
	loc := birdLocalsFromStore(st, tenantID)
	if st == nil || strings.TrimSpace(speakerID) == "" {
		return loc
	}
	sp, err := st.GetSpeaker(tenantID, speakerID)
	if err != nil || sp == nil {
		return loc
	}
	meta := store.ParseSpeakerMeta(sp.MetaJSON)
	src := strings.TrimSpace(meta.BirdBgpSourceIPv4)
	if src == "" {
		src = strings.TrimSpace(meta.NodeIPv4)
	}
	if src != "" {
		loc.routerID = src
		loc.localV4 = src
	}
	if s := strings.TrimSpace(meta.BirdBgpSourceIPv6); s != "" {
		loc.localV6 = s
	}
	return loc
}

// OverlayFragmentsForSpeaker re-renders bird.conf and peers fragment with speaker-specific BIRD locals.
func OverlayFragmentsForSpeaker(st store.Backend, tenantID, speakerID, revisionID string, frags map[string]string) (map[string]string, error) {
	if frags == nil {
		frags = map[string]string{}
	}
	locals := BirdLocalsForSpeaker(st, tenantID, speakerID)
	out := make(map[string]string, len(frags))
	for k, v := range frags {
		out[k] = v
	}
	moduleHint := "aggregate"
	if main := frags["bird.conf"]; main != "" {
		if idx := strings.Index(main, "trigger module "); idx >= 0 {
			rest := main[idx+len("trigger module "):]
			if end := strings.Index(rest, ")"); end > 0 {
				moduleHint = strings.TrimSpace(rest[:end])
			}
		}
	}
	main, err := birdfmt.RenderMainBirdConf(birdfmt.MainBirdConfOptions{
		RouterID: locals.routerID,
		Includes: birdfmt.StandardIncludeFragments(),
		Preamble: fmt.Sprintf("EvoBGP tenant aggregate config (trigger module %s) revision %s speaker %s", moduleHint, revisionID, speakerID),
	})
	if err != nil {
		return nil, err
	}
	out["bird.conf"] = main
	peersBody, err := renderPeersBirdFragment(st, tenantID, locals)
	if err != nil {
		return nil, err
	}
	pPeers := birdfmt.FragmentIncludePath(birdfmt.FragmentPeers)
	out[pPeers] = peersBody
	return out, nil
}