package repository

import (
	"context"
	"encoding/json"

	"github.com/google/uuid"
)

func (p *Postgres) seedDemo(ctx context.Context) error {
	var n int
	if err := p.pool.QueryRow(ctx, `SELECT COUNT(*)::int FROM tenant`).Scan(&n); err != nil {
		return err
	}
	if n > 0 {
		return p.attachDemoIDs(ctx)
	}

	tid := uuid.NewString()
	mCDN := uuid.NewString()
	mIP := uuid.NewString()
	parent := uuid.NewString()
	rid := uuid.NewString()
	sid := uuid.NewString()
	cid := uuid.NewString()
	p1 := uuid.NewString()
	p2 := uuid.NewString()

	preview := map[string]any{
		"preview_fragments": map[string]string{
			"bird.conf": `# EvoBGP demo bundle
router id 192.0.2.1;

protocol device {
}

protocol direct {
    ipv4;
    ipv6;
}
`,
			"bird.d/evobgp_demo.conf": "# static demo fragment\n",
		},
		"materialized_prefix_count": 128,
	}
	previewB, _ := json.Marshal(preview)
	parentMeta, _ := json.Marshal(map[string]any{
		"preview_fragments":         map[string]string{"bird.conf": "# parent revision\n"},
		"materialized_prefix_count": 0,
	})

	tx, err := p.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer func() { _ = tx.Rollback(ctx) }()

	if _, err := tx.Exec(ctx, `INSERT INTO tenant (id, name, slug) VALUES ($1,'Demo','demo')`, tid); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `INSERT INTO bgp_community (id, tenant_id, name, kind, value_json) VALUES ($1,$2,'demo-comm','large','{}')`, cid, tid); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO module (id, tenant_id, type, name, enabled, priority, refresh_interval_sec)
		VALUES ($1,$2,'CDN_CIDRS','demo-cdn',true,10,3600)`, mCDN, tid); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO module (id, tenant_id, type, name, enabled, priority)
		VALUES ($1,$2,'IP_RANGES','demo-static',true,20)`, mIP, tid); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO config_revision (id, tenant_id, content_hash, parent_revision_id, meta_json)
		VALUES ($1,$2,'sha256:parent',NULL,$3::jsonb)`, parent, tid, string(parentMeta)); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO config_revision (id, tenant_id, content_hash, parent_revision_id, meta_json)
		VALUES ($1,$2,'sha256:demo-rev-1',$3::uuid,$4::jsonb)`, rid, tid, parent, string(previewB)); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO revision_materialized_prefix (revision_id, prefix, community_id, source)
		VALUES ($1::uuid,'203.0.113.0/24',$2::uuid,'demo'), ($1::uuid,'2001:db8::/32',$2::uuid,'demo')`, rid, cid); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO bgp_speaker (id, tenant_id, role, endpoint, published_revision_id, published_at)
		VALUES ($1,$2,'replica','10.0.0.2:179',$3::uuid, now())`, sid, tid, rid); err != nil {
		return err
	}
	meta4 := `{"name":"demo-upstream-4","session_state":"Established"}`
	meta6 := `{"name":"demo-upstream-6","session_state":"Idle"}`
	if _, err := tx.Exec(ctx, `
		INSERT INTO bgp_peer (id, tenant_id, bgp_speaker_id, neighbor, remote_asn, enabled, policies_json, meta_json)
		VALUES ($1,$2,$3::uuid,'198.51.100.2'::inet,65001,true,'{}',$4::jsonb)`, p1, tid, sid, meta4); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO bgp_peer (id, tenant_id, bgp_speaker_id, neighbor, remote_asn, enabled, policies_json, meta_json)
		VALUES ($1,$2,$3::uuid,'2001:db8::2'::inet,65002,true,'{}',$4::jsonb)`, p2, tid, sid, meta6); err != nil {
		return err
	}
	if err := tx.Commit(ctx); err != nil {
		return err
	}
	p.demoTenant, p.demoCDN, p.demoIP, p.demoRev, p.demoSpk = tid, mCDN, mIP, rid, sid
	return nil
}

// attachDemoIDs fills demo pointer fields when DB already has data (e.g. compose restart).
func (p *Postgres) attachDemoIDs(ctx context.Context) error {
	if err := p.pool.QueryRow(ctx, `SELECT id::text FROM tenant WHERE slug = 'demo' ORDER BY created_at LIMIT 1`).Scan(&p.demoTenant); err != nil {
		return nil // non-fatal: no demo tenant
	}
	_ = p.pool.QueryRow(ctx, `SELECT id::text FROM module WHERE tenant_id = $1::uuid AND name = 'demo-cdn' LIMIT 1`, p.demoTenant).Scan(&p.demoCDN)
	_ = p.pool.QueryRow(ctx, `SELECT id::text FROM module WHERE tenant_id = $1::uuid AND name = 'demo-static' LIMIT 1`, p.demoTenant).Scan(&p.demoIP)
	_ = p.pool.QueryRow(ctx, `
		SELECT id::text FROM config_revision WHERE tenant_id = $1::uuid AND content_hash LIKE 'sha256:demo%' ORDER BY created_at DESC LIMIT 1`, p.demoTenant).Scan(&p.demoRev)
	_ = p.pool.QueryRow(ctx, `SELECT id::text FROM bgp_speaker WHERE tenant_id = $1::uuid LIMIT 1`, p.demoTenant).Scan(&p.demoSpk)
	return nil
}