package main

import (
	"context"
	"encoding/json"
	"strings"

	"atlas9.dev/c/core"
	"atlas9.dev/c/core/dbi"
	"atlas9.dev/c/core/iam"
)

type SqliteRoleStore struct {
	db dbi.DBI
}

var _ iam.RoleStore = (*SqliteRoleStore)(nil)

func NewSqliteRoleStore(db dbi.DBI) *SqliteRoleStore {
	return &SqliteRoleStore{db: db}
}

func (s *SqliteRoleStore) Save(ctx context.Context, role *iam.Role) (bool, error) {
	if err := role.ID.Valid(); err != nil {
		return false, err
	}

	actions, err := json.Marshal(role.Actions)
	if err != nil {
		return false, err
	}

	res, err := s.db.Exec(ctx, `
		INSERT INTO roles (id, name, actions) VALUES ($1, $2, $3)
		ON CONFLICT (id) DO NOTHING
	`, role.ID, role.Name, string(actions))
	if err != nil {
		return false, err
	}

	n, err := res.RowsAffected()
	if err != nil {
		return false, err
	}
	created := n > 0

	if !created {
		r, err := s.Get(ctx, role.ID)
		if err != nil {
			return false, err
		}
		*role = *r
	}
	return created, nil
}

func (s *SqliteRoleStore) Get(ctx context.Context, id iam.RoleID) (*iam.Role, error) {
	row := s.db.QueryRow(ctx, `SELECT id, name, actions FROM roles WHERE id = $1`, id)

	var role iam.Role
	var actionsJSON string
	if err := row.Scan(&role.ID, &role.Name, &actionsJSON); err != nil {
		return nil, err
	}
	if err := json.Unmarshal([]byte(actionsJSON), &role.Actions); err != nil {
		return nil, err
	}
	return &role, nil
}

func (s *SqliteRoleStore) Delete(ctx context.Context, id iam.RoleID) error {
	_, err := s.db.Exec(ctx, `DELETE FROM roles WHERE id = $1`, id)
	return err
}

func (s *SqliteRoleStore) List(ctx context.Context, page core.PageReq) (core.Page[iam.Role], error) {
	limit := page.Limit
	if limit <= 0 {
		limit = 100
	}
	rows, err := s.db.Query(ctx, `
		SELECT id, name, actions FROM roles
		WHERE id > $1 ORDER BY id LIMIT $2
	`, page.Cursor, limit)
	if err != nil {
		return core.Page[iam.Role]{}, err
	}
	defer rows.Close()

	var items []iam.Role
	for rows.Next() {
		var r iam.Role
		var actionsJSON string
		if err := rows.Scan(&r.ID, &r.Name, &actionsJSON); err != nil {
			return core.Page[iam.Role]{}, err
		}
		if err := json.Unmarshal([]byte(actionsJSON), &r.Actions); err != nil {
			return core.Page[iam.Role]{}, err
		}
		items = append(items, r)
	}
	if err := rows.Err(); err != nil {
		return core.Page[iam.Role]{}, err
	}
	var cursor string
	if len(items) == limit {
		cursor = string(items[limit-1].ID)
	}
	return core.Page[iam.Role]{Items: items, Cursor: cursor}, nil
}

func (s *SqliteRoleStore) ListByNamespace(ctx context.Context, namespace string, page core.PageReq) (core.Page[iam.Role], error) {
	limit := page.Limit
	if limit <= 0 {
		limit = 100
	}
	pattern := escapeLikeRole(namespace) + ".%"
	rows, err := s.db.Query(ctx, `
		SELECT id, name, actions FROM roles
		WHERE id LIKE $1 ESCAPE '\' AND id > $2 ORDER BY id LIMIT $3
	`, pattern, page.Cursor, limit)
	if err != nil {
		return core.Page[iam.Role]{}, err
	}
	defer rows.Close()

	var items []iam.Role
	for rows.Next() {
		var r iam.Role
		var actionsJSON string
		if err := rows.Scan(&r.ID, &r.Name, &actionsJSON); err != nil {
			return core.Page[iam.Role]{}, err
		}
		if err := json.Unmarshal([]byte(actionsJSON), &r.Actions); err != nil {
			return core.Page[iam.Role]{}, err
		}
		items = append(items, r)
	}
	if err := rows.Err(); err != nil {
		return core.Page[iam.Role]{}, err
	}
	var cursor string
	if len(items) == limit {
		cursor = string(items[limit-1].ID)
	}
	return core.Page[iam.Role]{Items: items, Cursor: cursor}, nil
}

func escapeLikeRole(s string) string {
	s = strings.ReplaceAll(s, `\`, `\\`)
	s = strings.ReplaceAll(s, `%`, `\%`)
	s = strings.ReplaceAll(s, `_`, `\_`)
	return s
}