package store

import (
	"context"
	"encoding/json"
	"time"

	"github.com/jackc/pgx/v5"
)

type Blog struct {
	ID        int64
	OwnerID   int64
	Subdomain string
	Title     string
	Tagline   string
	ThemeJSON json.RawMessage
	CreatedAt time.Time
	UpdatedAt time.Time
}

const blogCols = `id, owner_id, subdomain, title, tagline, theme, created_at, updated_at`

func scanBlog(row interface{ Scan(...any) error }) (*Blog, error) {
	var b Blog
	err := row.Scan(&b.ID, &b.OwnerID, &b.Subdomain, &b.Title, &b.Tagline, &b.ThemeJSON, &b.CreatedAt, &b.UpdatedAt)
	if err != nil {
		return nil, wrap(err)
	}
	return &b, nil
}

// CreateBlogger creates a user, their blog and a default home page in one transaction.
func (s *Store) CreateBlogger(ctx context.Context, username, passwordHash, subdomain, title string) (*User, *Blog, error) {
	tx, err := s.db.Begin(ctx)
	if err != nil {
		return nil, nil, err
	}
	defer tx.Rollback(ctx)

	u, err := scanUser(tx.QueryRow(ctx, `INSERT INTO users (username, password_hash, role) VALUES ($1,$2,$3) RETURNING `+userCols,
		username, passwordHash, RoleBlogger))
	if err != nil {
		return nil, nil, err
	}
	b, err := createBlog(ctx, tx, u.ID, subdomain, title)
	if err != nil {
		return nil, nil, err
	}
	if err := tx.Commit(ctx); err != nil {
		return nil, nil, err
	}
	return u, b, nil
}

// CreateBlog creates a blog with a default home page for an existing user.
func (s *Store) CreateBlog(ctx context.Context, ownerID int64, subdomain, title string) (*Blog, error) {
	tx, err := s.db.Begin(ctx)
	if err != nil {
		return nil, err
	}
	defer tx.Rollback(ctx)
	b, err := createBlog(ctx, tx, ownerID, subdomain, title)
	if err != nil {
		return nil, err
	}
	return b, tx.Commit(ctx)
}

func createBlog(ctx context.Context, tx pgx.Tx, ownerID int64, subdomain, title string) (*Blog, error) {
	b, err := scanBlog(tx.QueryRow(ctx, `INSERT INTO blogs (owner_id, subdomain, title) VALUES ($1,$2,$3) RETURNING `+blogCols,
		ownerID, subdomain, title))
	if err != nil {
		return nil, err
	}
	_, err = tx.Exec(ctx, `INSERT INTO pages (blog_id, slug, title, nav_order, is_home) VALUES ($1,'home','Home',0,true)`, b.ID)
	if err != nil {
		return nil, wrap(err)
	}
	return b, nil
}

func (s *Store) BlogByID(ctx context.Context, id int64) (*Blog, error) {
	return scanBlog(s.db.QueryRow(ctx, `SELECT `+blogCols+` FROM blogs WHERE id=$1`, id))
}

func (s *Store) BlogBySubdomain(ctx context.Context, sub string) (*Blog, error) {
	return scanBlog(s.db.QueryRow(ctx, `SELECT `+blogCols+` FROM blogs WHERE subdomain=$1`, sub))
}

func (s *Store) BlogByOwner(ctx context.Context, ownerID int64) (*Blog, error) {
	return scanBlog(s.db.QueryRow(ctx, `SELECT `+blogCols+` FROM blogs WHERE owner_id=$1`, ownerID))
}

func (s *Store) UpdateBlogSettings(ctx context.Context, id int64, title, tagline string) error {
	_, err := s.db.Exec(ctx, `UPDATE blogs SET title=$2, tagline=$3, updated_at=now() WHERE id=$1`, id, title, tagline)
	return err
}

func (s *Store) UpdateBlogTheme(ctx context.Context, id int64, theme json.RawMessage) error {
	_, err := s.db.Exec(ctx, `UPDATE blogs SET theme=$2, updated_at=now() WHERE id=$1`, id, theme)
	return err
}

func (s *Store) DeleteBlog(ctx context.Context, id int64) error {
	_, err := s.db.Exec(ctx, `DELETE FROM blogs WHERE id=$1`, id)
	return err
}