package bnwasm

import (
	"context"
	"testing"

	abiv1 "git.dev.alexdunmow.com/block/pluginsdk/abi/v1"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"
	"github.com/jackc/pgx/v5/pgtype"
)

// --- Vendored sqlc output ---------------------------------------------------
//
// The block below is byte-for-byte in the shape `sqlc generate` emits for the
// pgx/v5 sql_package with the same overrides symposium uses (uuid→uuid.UUID,
// jsonb→json.RawMessage, emit_pointers_for_null_types). It is checked in so a
// compile of THIS test is proof that generated plugin code binds to the bnwasm
// Pool/Tx (as its DBTX) and pgxRows/pgxRow (via Scan) with no edits — the same
// DBTX interface, the same pgconn.CommandTag / pgx.Rows / pgx.Row signatures.

type DBTX interface {
	Exec(context.Context, string, ...any) (pgconn.CommandTag, error)
	Query(context.Context, string, ...any) (pgx.Rows, error)
	QueryRow(context.Context, string, ...any) pgx.Row
}

func New(db DBTX) *Queries { return &Queries{db: db} }

type Queries struct{ db DBTX }

func (q *Queries) WithTx(tx pgx.Tx) *Queries { return &Queries{db: tx} }

type Widget struct {
	ID        uuid.UUID          `json:"id"`
	Name      string             `json:"name"`
	Notes     *string            `json:"notes"`
	Count     int32              `json:"count"`
	CreatedAt pgtype.Timestamptz `json:"created_at"`
}

const createWidget = `-- name: CreateWidget :one
INSERT INTO widgets (name, notes) VALUES ($1, $2) RETURNING id
`

type CreateWidgetParams struct {
	Name  string  `json:"name"`
	Notes *string `json:"notes"`
}

func (q *Queries) CreateWidget(ctx context.Context, arg CreateWidgetParams) (uuid.UUID, error) {
	row := q.db.QueryRow(ctx, createWidget, arg.Name, arg.Notes)
	var id uuid.UUID
	err := row.Scan(&id)
	return id, err
}

const getWidget = `-- name: GetWidget :one
SELECT id, name, notes, count, created_at FROM widgets WHERE id = $1
`

func (q *Queries) GetWidget(ctx context.Context, id uuid.UUID) (Widget, error) {
	row := q.db.QueryRow(ctx, getWidget, id)
	var i Widget
	err := row.Scan(&i.ID, &i.Name, &i.Notes, &i.Count, &i.CreatedAt)
	return i, err
}

const listWidgets = `-- name: ListWidgets :many
SELECT id, name, notes, count, created_at FROM widgets ORDER BY name
`

func (q *Queries) ListWidgets(ctx context.Context) ([]Widget, error) {
	rows, err := q.db.Query(ctx, listWidgets)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var items []Widget
	for rows.Next() {
		var i Widget
		if err := rows.Scan(&i.ID, &i.Name, &i.Notes, &i.Count, &i.CreatedAt); err != nil {
			return nil, err
		}
		items = append(items, i)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}
	return items, nil
}

const deleteWidget = `-- name: DeleteWidget :exec
DELETE FROM widgets WHERE id = $1
`

func (q *Queries) DeleteWidget(ctx context.Context, id uuid.UUID) error {
	_, err := q.db.Exec(ctx, deleteWidget, id)
	return err
}

// --- Compile-time proof the bnwasm surfaces satisfy the generated interfaces --

var (
	_ DBTX   = (*Pool)(nil)
	_ DBTX   = (*Tx)(nil)
	_ pgx.Tx = (*Tx)(nil)
)

// --- End-to-end runs against the fake host ----------------------------------

func widgetRow(id uuid.UUID, name string, count int32) *abiv1.DbRow {
	return &abiv1.DbRow{Values: []*abiv1.DbValue{
		{Kind: &abiv1.DbValue_UuidValue{UuidValue: id.String()}},
		{Kind: &abiv1.DbValue_StringValue{StringValue: name}},
		{Kind: &abiv1.DbValue_Null{Null: true}}, // notes → NULL → (*string)(nil)
		{Kind: &abiv1.DbValue_Int64Value{Int64Value: int64(count)}},
		{Kind: &abiv1.DbValue_Null{Null: true}}, // created_at → NULL Timestamptz
	}}
}

func TestSqlcGetWidget(t *testing.T) {
	id := uuid.New()
	host := &fakeHost{queryResp: &abiv1.DbRowsResponse{
		Columns: []string{"id", "name", "notes", "count", "created_at"},
		Rows:    []*abiv1.DbRow{widgetRow(id, "gadget", 3)},
	}}
	q := New(NewPool(host.call))

	w, err := q.GetWidget(context.Background(), id)
	if err != nil {
		t.Fatal(err)
	}
	if w.ID != id || w.Name != "gadget" || w.Count != 3 {
		t.Fatalf("unexpected widget: %+v", w)
	}
	if w.Notes != nil {
		t.Fatalf("notes should be nil for NULL column, got %v", *w.Notes)
	}
	if w.CreatedAt.Valid {
		t.Fatalf("created_at should be invalid for NULL column")
	}
}

func TestSqlcListWidgets(t *testing.T) {
	host := &fakeHost{queryResp: &abiv1.DbRowsResponse{
		Columns: []string{"id", "name", "notes", "count", "created_at"},
		Rows: []*abiv1.DbRow{
			widgetRow(uuid.New(), "alpha", 1),
			widgetRow(uuid.New(), "beta", 2),
		},
	}}
	q := New(NewPool(host.call))

	items, err := q.ListWidgets(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if len(items) != 2 || items[0].Name != "alpha" || items[1].Name != "beta" {
		t.Fatalf("unexpected list: %+v", items)
	}
}

// TestSqlcWithTxCreate proves the generated WithTx path binds to the bnwasm Tx
// and that CreateWidget's RETURNING id scans, all inside one transaction with
// the right ordered host calls.
func TestSqlcWithTxCreate(t *testing.T) {
	newID := uuid.New()
	host := &fakeHost{
		txHandle: 42,
		queryResp: &abiv1.DbRowsResponse{
			Columns: []string{"id"},
			Rows:    []*abiv1.DbRow{{Values: []*abiv1.DbValue{{Kind: &abiv1.DbValue_UuidValue{UuidValue: newID.String()}}}}},
		},
	}
	pool := NewPool(host.call)
	ctx := context.Background()

	tx, err := pool.Begin(ctx)
	if err != nil {
		t.Fatal(err)
	}
	notes := "hi"
	gotID, err := New(pool).WithTx(tx).CreateWidget(ctx, CreateWidgetParams{Name: "w", Notes: &notes})
	if err != nil {
		t.Fatal(err)
	}
	if gotID != newID {
		t.Fatalf("returning id: want %s got %s", newID, gotID)
	}
	if err := tx.Commit(ctx); err != nil {
		t.Fatal(err)
	}

	// begin → query(RETURNING) → commit; the query carried the tx handle.
	if got := host.methods(); len(got) != 3 || got[0] != methodTxBegin || got[1] != methodQuery || got[2] != methodTxCommit {
		t.Fatalf("method sequence: %v", got)
	}
	if host.calls[1].txHandle != 42 {
		t.Fatalf("in-tx query should carry handle 42, got %d", host.calls[1].txHandle)
	}
	// The NULL-able *string arg marshaled as a real string arg.
	if len(host.calls[1].args) != 2 {
		t.Fatalf("want 2 args, got %d", len(host.calls[1].args))
	}
}