package db

import (
	"context"
	"fmt"
	"net/http"
	"strings"

	"github.com/H1K0/Kiraku/internal/models"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"
)

func RolesGet(ctx context.Context, user_id, filter, sort string, limit, offset int) (roles models.Roles, statusCode int, err error) {
	ok, _ := UserAuth(ctx, user_id)
	if !ok {
		err = fmt.Errorf("unauthorized")
		statusCode = http.StatusUnauthorized
		return
	}
	queryGet := "SELECT id, name FROM roles WHERE POSITION($1 IN LOWER(name))>0"
	if sort != "" {
		sort_options := strings.Split(sort, ",")
		queryGet += " ORDER BY "
		for i, sort_option := range sort_options {
			sort_order := sort_option[:1]
			sort_field := sort_option[1:]
			switch sort_order {
			case "+":
				sort_order = "ASC"
			case "-":
				sort_order = "DESC"
			default:
				err = fmt.Errorf("invalid sorting order mark: %q", sort)
				statusCode = http.StatusBadRequest
				return
			}
			switch sort_field {
			case "name":
			default:
				err = fmt.Errorf("invalid sorting field: %q", sort_field)
				statusCode = http.StatusBadRequest
				return
			}
			if i > 0 {
				queryGet += ", "
			}
			queryGet += fmt.Sprintf("%s %s NULLS LAST", sort_field, sort_order)
		}
	}
	queryCount := queryGet
	if limit >= 0 {
		queryGet += fmt.Sprintf(" LIMIT %d", limit)
	}
	if offset > 0 {
		queryGet += fmt.Sprintf(" OFFSET %d", offset)
	}
	filter = strings.ToLower(filter)
	statusCode, err = transaction(ctx, func(tx pgx.Tx) (statusCode int, err error) {
		rows, err := tx.Query(ctx, queryGet, filter)
		if err != nil {
			statusCode = http.StatusInternalServerError
			return
		}
		count := 0
		for rows.Next() {
			var role models.Role
			err = rows.Scan(&role.ID, &role.Name)
			if err != nil {
				statusCode = http.StatusInternalServerError
				return
			}
			roles.Roles = append(roles.Roles, role)
			count++
		}
		err = rows.Err()
		if err != nil {
			statusCode = http.StatusInternalServerError
			return
		}
		roles.Pagination.Limit = limit
		roles.Pagination.Offset = offset
		roles.Pagination.Count = count
		queryCount = fmt.Sprintf("SELECT COUNT(*) FROM (%s) tmp", queryCount)
		row := tx.QueryRow(ctx, queryCount, filter)
		err = row.Scan(&roles.Pagination.Total)
		if err != nil {
			statusCode = http.StatusInternalServerError
		}
		return
	})
	if err != nil {
		return
	}
	statusCode = http.StatusOK
	return
}

func RoleGet(ctx context.Context, user_id, person_id string) (role models.Role, statusCode int, err error) {
	ok, _ := UserAuth(ctx, user_id)
	if !ok {
		err = fmt.Errorf("unauthorized")
		statusCode = http.StatusUnauthorized
		return
	}
	row := connPool.QueryRow(ctx, "SELECT id, name FROM roles WHERE id=$1", person_id)
	err = row.Scan(&role.ID, &role.Name)
	if err != nil {
		if err == pgx.ErrNoRows {
			err = fmt.Errorf("not found")
			statusCode = http.StatusNotFound
			return
		}
		pgErr := err.(*pgconn.PgError)
		if pgErr.Code == "22P02" || pgErr.Code == "22007" {
			err = fmt.Errorf("%s", pgErr.Message)
			statusCode = http.StatusBadRequest
		} else {
			statusCode = http.StatusInternalServerError
		}
		return
	}
	statusCode = http.StatusOK
	return
}

func RoleAdd(ctx context.Context, user_id, name string) (role models.Role, statusCode int, err error) {
	ok, editor := UserAuth(ctx, user_id)
	if !ok {
		err = fmt.Errorf("unauthorized")
		statusCode = http.StatusUnauthorized
		return
	}
	if !editor {
		err = fmt.Errorf("not allowed")
		statusCode = http.StatusForbidden
		return
	}
	row := connPool.QueryRow(ctx, "INSERT INTO roles (name) VALUES ($1) RETURNING id, name", name)
	err = row.Scan(&role.ID, &role.Name)
	if err != nil {
		pgErr := err.(*pgconn.PgError)
		if pgErr.Code == "22P02" || pgErr.Code == "22007" {
			err = fmt.Errorf("%s", pgErr.Message)
			statusCode = http.StatusBadRequest
		} else if pgErr.Code == "23505" {
			err = fmt.Errorf("a role with this name already exists")
			statusCode = http.StatusConflict
		} else {
			statusCode = http.StatusInternalServerError
		}
		return
	}
	statusCode = http.StatusOK
	return
}

func RoleUpdate(ctx context.Context, user_id, role_id string, values map[string]string) (role models.Role, statusCode int, err error) {
	ok, editor := UserAuth(ctx, user_id)
	if !ok {
		err = fmt.Errorf("unauthorized")
		statusCode = http.StatusUnauthorized
		return
	}
	if !editor {
		err = fmt.Errorf("not allowed")
		statusCode = http.StatusForbidden
		return
	}
	statusCode, err = transaction(ctx, func(tx pgx.Tx) (statusCode int, err error) {
		for _, field := range []string{"name"} {
			value, ok := values[field]
			if !ok {
				continue
			}
			var commandTag pgconn.CommandTag
			commandTag, err = tx.Exec(ctx, fmt.Sprintf("UPDATE roles SET %s=NULLIF($2, '') WHERE id=$1", field), role_id, value)
			if err != nil {
				pgErr := err.(*pgconn.PgError)
				if pgErr.Code == "22P02" || pgErr.Code == "22007" {
					err = fmt.Errorf("%s", pgErr.Message)
					statusCode = http.StatusBadRequest
				} else if pgErr.Code == "23505" {
					err = fmt.Errorf("a person with this name already exists")
					statusCode = http.StatusConflict
				} else {
					statusCode = http.StatusInternalServerError
				}
				return
			}
			if commandTag.RowsAffected() == 0 {
				err = fmt.Errorf("not found")
				statusCode = http.StatusNotFound
				return
			}
		}
		row := tx.QueryRow(ctx, "SELECT id, name FROM roles WHERE id=$1", role_id)
		err = row.Scan(&role.ID, &role.Name)
		if err != nil {
			statusCode = http.StatusInternalServerError
		}
		return
	})
	if err != nil {
		return
	}
	statusCode = http.StatusOK
	return
}

func RoleDelete(ctx context.Context, user_id, role_id string) (statusCode int, err error) {
	ok, editor := UserAuth(ctx, user_id)
	if !ok {
		err = fmt.Errorf("unauthorized")
		statusCode = http.StatusUnauthorized
		return
	}
	if !editor {
		err = fmt.Errorf("not allowed")
		statusCode = http.StatusForbidden
		return
	}
	commandTag, err := connPool.Exec(ctx, "DELETE FROM roles WHERE id=$1", role_id)
	if err != nil {
		pgErr := err.(*pgconn.PgError)
		if pgErr.Code == "22P02" {
			err = fmt.Errorf("%s", pgErr.Message)
			statusCode = http.StatusBadRequest
		} else {
			statusCode = http.StatusInternalServerError
		}
		return
	}
	if commandTag.RowsAffected() == 0 {
		err = fmt.Errorf("not found")
		statusCode = http.StatusNotFound
		return
	}
	statusCode = http.StatusNoContent
	return
}