package api

import (
	"context"
	"errors"
	"fmt"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/gofiber/fiber/v3"
	"github.com/gofiber/fiber/v3/middleware/cors"
	"github.com/gofiber/fiber/v3/middleware/favicon"
	"github.com/gofiber/fiber/v3/middleware/logger"
	recover "github.com/gofiber/fiber/v3/middleware/recover"
	"github.com/gofiber/fiber/v3/middleware/static"

	"prayertimes/pkg/prayer"
	"prayertimes/templates"
)

type httpError struct {
	Message string `json:"message"`
}

type Services struct {
	Provider DiyanetProvider
}

type DiyanetProvider interface {
	Get(ctx context.Context, locationID string) ([]prayer.Times, error)
	GetByCoords(ctx context.Context, coords prayer.Coordinates) ([]prayer.Times, error)
	SearchLocations(ctx context.Context, query string) ([]prayer.Location, error)
}

func New(services Services) *fiber.App {
	app := fiber.New(fiber.Config{
		Immutable:    true,
		ReadTimeout:  time.Second * 10,
		WriteTimeout: time.Second * 30,
		ErrorHandler: func(ctx fiber.Ctx, err error) error {
			if errors.Is(err, prayer.ErrInvalidLocation) {
				return ctx.Status(http.StatusUnprocessableEntity).JSON(httpError{
					Message: err.Error(),
				})
			}

			return fiber.DefaultErrorHandler(ctx, err)
		},
	})

	app.Use(
		favicon.New(),
		recover.New(recover.Config{EnableStackTrace: true}),
		logger.New(),
		cors.New(),
	)

	app.Get("/healthz", func(ctx fiber.Ctx) error {
		return ctx.SendString("OK")
	})

	app.Get("/api/v1/diyanet/prayertimes", func(ctx fiber.Ctx) error {
		var query struct {
			LocationID string `query:"location_id"`
			Latitude   string `query:"latitude"`
			Longitude  string `query:"longitude"`
		}
		if err := ctx.Bind().Query(&query); err != nil {
			return fmt.Errorf("failed to bind prayer times query parameters: %w", errors.Join(fiber.ErrBadRequest, err))
		}

		locationID := strings.TrimSpace(query.LocationID)
		latitude := strings.TrimSpace(query.Latitude)
		longitude := strings.TrimSpace(query.Longitude)

		var (
			times []prayer.Times
			err   error
		)

		switch {
		case locationID != "":
			times, err = services.Provider.Get(ctx.Context(), locationID)
		case latitude != "" && longitude != "":
			lat, latErr := strconv.ParseFloat(latitude, 64)
			if latErr != nil {
				return fmt.Errorf("failed to parse latitude query parameter: %w", errors.Join(fiber.ErrBadRequest, latErr))
			}
			lng, lngErr := strconv.ParseFloat(longitude, 64)
			if lngErr != nil {
				return fmt.Errorf("failed to parse longitude query parameter: %w", errors.Join(fiber.ErrBadRequest, lngErr))
			}

			times, err = services.Provider.GetByCoords(ctx.Context(), prayer.Coordinates{
				Latitude:  lat,
				Longitude: lng,
			})
		default:
			return fmt.Errorf("failed to validate prayer times query parameters: %w", fiber.ErrBadRequest)
		}

		if err != nil {
			return fmt.Errorf("failed to fetch prayer times: %w", err)
		}

		ctx.Response().Header.Set(fiber.HeaderCacheControl, "max-age=86400")
		return ctx.JSON(fiber.Map{
			"prayertimes": times,
		})
	})

	app.Get("/api/v1/diyanet/location", func(ctx fiber.Ctx) error {
		var query struct {
			Text string `query:"query"`
		}
		if err := ctx.Bind().Query(&query); err != nil {
			return fmt.Errorf("failed to bind location query parameters: %w", errors.Join(fiber.ErrBadRequest, err))
		}

		query.Text = strings.TrimSpace(query.Text)
		if query.Text == "" {
			return fmt.Errorf("failed to validate location query parameters: %w", fiber.ErrBadRequest)
		}

		locations, err := services.Provider.SearchLocations(ctx.Context(), query.Text)
		if err != nil {
			return fmt.Errorf("failed to search locations: %w", err)
		}

		ctx.Response().Header.Set(fiber.HeaderCacheControl, "max-age=86400")
		return ctx.JSON(fiber.Map{
			"locations": locations,
		})
	})

	app.Use("/", static.New("", static.Config{FS: templates.FS()}))

	return app
}