package link

import (
	. "cgnolink/err"
	"encoding/json"
	"github.com/jackc/pgx/v4/pgxpool"
	"github.com/labstack/echo/v4"
	"net/http"
	"strconv"
)

func redirectHandler(c echo.Context, pool *pgxpool.Pool) error {
	linkId := c.Param("id")

	serv := PgService{rep: PgRepository{pool: pool}}

	link, err := serv.GetById(linkId)
	if err != nil {
		return MapErrToHTTPErr(err)
	}

	return c.Redirect(http.StatusSeeOther, link.RedirectURL.String())
}

func creationHandler(c echo.Context, pool *pgxpool.Pool) error {
	var model CreationModel
	if err := json.NewDecoder(c.Request().Body).Decode(&model); err != nil {
		return echo.NewHTTPError(http.StatusBadRequest, "Invalid data format.")
	}

	entity, err := model.MapModelToEntity()
	if err != nil {
		return echo.NewHTTPError(http.StatusBadRequest, "Invalid URL.")
	}

	serv := PgService{rep: PgRepository{pool: pool}}

	if err = serv.Create(entity); err != nil {
		return MapErrToHTTPErr(err)
	}

	return c.NoContent(http.StatusCreated)
}

func retrievalByIdHandler(c echo.Context, pool *pgxpool.Pool) error {
	linkId := c.Param("id")

	serv := PgService{rep: PgRepository{pool: pool}}

	l, err := serv.GetById(linkId)
	if err != nil {
		return MapErrToHTTPErr(err)
	}

	return c.JSON(http.StatusOK, MapEntityToModel(l))
}

func allRetrievalHandler(c echo.Context, pool *pgxpool.Pool) error {
	limit := 20
	if v := c.QueryParam("limit"); v != "" {
		num, err := strconv.Atoi(v)
		if err != nil {
			return echo.NewHTTPError(http.StatusBadRequest, "Invalid limit value.")
		}

		limit = num
	}

	offset := 0
	if v := c.QueryParam("offset"); v != "" {
		num, err := strconv.Atoi(v)
		if err != nil {
			return echo.NewHTTPError(http.StatusBadRequest, "Invalid offset value.")
		}

		offset = num
	}

	serv := PgService{rep: PgRepository{pool: pool}}

	links, err := serv.GetAll(limit, offset)
	if err != nil {
		return MapErrToHTTPErr(err)
	}

	models := make([]ResourceModel, len(links))
	for i, v := range links {
		models[i] = MapEntityToModel(v)
	}

	return c.JSON(http.StatusOK, models)
}

func removalHandler(c echo.Context, pool *pgxpool.Pool) error {
	linkId := c.Param("id")

	serv := PgService{rep: PgRepository{pool: pool}}

	if err := serv.DeleteById(linkId); err != nil {
		return MapErrToHTTPErr(err)
	}

	return c.NoContent(http.StatusNoContent)
}

func AddHandlers(s *echo.Echo, pool *pgxpool.Pool) {
	gr := s.Group("/links")

	gr.POST("", func(ctx echo.Context) error {
		return creationHandler(ctx, pool)
	})

	gr.GET("", func(ctx echo.Context) error {
		return allRetrievalHandler(ctx, pool)
	})

	gr.GET("/:id", func(ctx echo.Context) error {
		return retrievalByIdHandler(ctx, pool)
	})

	gr.DELETE("/:id", func(ctx echo.Context) error {
		return removalHandler(ctx, pool)
	})

	s.GET("/:id", func(ctx echo.Context) error {
		return redirectHandler(ctx, pool)
	})
}