package carpool

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"sort"
	"strconv"
	"time"

	"git.coopgo.io/coopgo-platform/carpool-service/interoperability/ocss"
	"github.com/google/uuid"
	"github.com/rs/zerolog/log"
)

type RDEXCarpoolAPI struct {
	OperatorId   string
	OperatorName string
	PublicKey    string
	PrivateKey   string
	BaseURL      string
}

func NewRDEXCarpoolAPI(operatorId string, operatorName string, apiKey string, baseURL string) (*RDEXCarpoolAPI, error) {
	// apiKey is expected to be in format "publicKey:privateKey"
	// For backward compatibility, if no colon, treat the whole string as private key
	publicKey := ""
	privateKey := apiKey

	// Try to split if it contains colon
	parts := []rune(apiKey)
	colonIdx := -1
	for i, r := range parts {
		if r == ':' {
			colonIdx = i
			break
		}
	}

	if colonIdx > 0 {
		publicKey = string(parts[:colonIdx])
		privateKey = string(parts[colonIdx+1:])
	}

	return &RDEXCarpoolAPI{
		OperatorId:   operatorId,
		OperatorName: operatorName,
		PublicKey:    publicKey,
		PrivateKey:   privateKey,
		BaseURL:      baseURL,
	}, nil
}

// RDEX Journey response structures
type RDEXJourney struct {
	UUID     *int64            `json:"uuid"`
	Operator *string           `json:"operator"`
	Origin   *string           `json:"origin"`
	URL      *string           `json:"url"`
	Driver   *RDEXUser         `json:"driver"`
	From     *RDEXWaypoint     `json:"from"`
	To       *RDEXWaypoint     `json:"to"`
	Distance *int64            `json:"distance"`
	Duration *int64            `json:"duration"`
	Cost     *RDEXCost         `json:"cost"`
	Outward  *RDEXOutward      `json:"outward"`
	Type     *string           `json:"type"`
	Frequency *string          `json:"frequency"`
}

type RDEXUser struct {
	UUID   *int64  `json:"uuid"`
	Alias  *string `json:"alias"`
	Image  *string `json:"image"`
	Gender *string `json:"gender"`
	Seats  *int64  `json:"seats"`
	State  *int    `json:"state"`
}

type RDEXCar struct {
	Model *string `json:"model"`
}

type RDEXWaypoint struct {
	Address    *string `json:"address"`
	City       *string `json:"city"`
	PostalCode *string `json:"postalcode"`
	Country    *string `json:"country"`
	Latitude   *string `json:"latitude"`
	Longitude  *string `json:"longitude"`
}

type RDEXCost struct {
	Variable *string `json:"variable"`
}

type RDEXOutward struct {
	MinDate *string            `json:"mindate"`
	MaxDate *string            `json:"maxdate"`
	Monday  *RDEXTimeRange     `json:"monday"`
}

type RDEXTimeRange struct {
	MinTime *string `json:"mintime"`
	MaxTime *string `json:"maxtime"`
}

type RDEXJourneysResponse struct {
	Journeys RDEXJourney `json:"journeys"`
}

func (api *RDEXCarpoolAPI) GetOperatorId() string {
	return api.OperatorId
}

func (api *RDEXCarpoolAPI) GetDriverJourneys(
	departureLat float64,
	departureLng float64,
	arrivalLat float64,
	arrivalLng float64,
	departureDate time.Time,
	timeDelta *time.Duration,
	departureRadius int64,
	arrivalRadius int64,
	count int64,
) ([]ocss.DriverJourney, error) {
	td := 1 * time.Hour
	if timeDelta != nil {
		td = *timeDelta
	}

	minDate := departureDate.Add(-td)
	maxDate := departureDate.Add(td)

	log.Info().
		Str("operator", api.OperatorId).
		Float64("departure_lat", departureLat).
		Float64("departure_lng", departureLng).
		Float64("arrival_lat", arrivalLat).
		Float64("arrival_lng", arrivalLng).
		Time("departure_date", departureDate).
		Time("min_date", minDate).
		Time("max_date", maxDate).
		Msg("RDEX GetDriverJourneys request")

	results, err := rdexSearch(
		api.BaseURL+"/rdex/journeys",
		api.PublicKey,
		api.PrivateKey,
		departureLat,
		departureLng,
		arrivalLat,
		arrivalLng,
		minDate,
		maxDate,
		true, // driver journeys
	)
	if err != nil {
		log.Error().Err(err).Str("operator", api.OperatorId).Msg("error in rdexSearch")
		return nil, err
	}

	log.Info().
		Str("operator", api.OperatorId).
		Int("raw_results_count", len(results)).
		Msg("RDEX search returned results")

	journeys := []ocss.DriverJourney{}

	for _, r := range results {
		// Skip if not a driver journey (check driver state)
		if r.Driver == nil {
			log.Debug().Msg("Skipping journey: Driver is nil")
			continue
		}
		if r.Driver.State == nil {
			log.Debug().Msg("Skipping journey: Driver.State is nil")
			continue
		}
		if *r.Driver.State != 1 {
			log.Debug().Int("state", *r.Driver.State).Msg("Skipping journey: Driver.State is not 1")
			continue
		}

		// Parse price from cost.variable
		var price *ocss.Price
		if r.Cost != nil && r.Cost.Variable != nil {
			// Parse the variable cost string (e.g., "0.060345") to float
			if costFloat, err := strconv.ParseFloat(*r.Cost.Variable, 64); err == nil {
				// Convert cost per km to total price (distance is in meters)
				if r.Distance != nil {
					totalPrice := costFloat * float64(*r.Distance) / 1000.0
					paying := ocss.Paying
					currency := "EUR"
					price = &ocss.Price{
						Type:     &paying,
						Amount:   &totalPrice,
						Currency: &currency,
					}
				}
			}
		}

		// Parse pickup datetime from outward
		var pickupDatetime ocss.OCSSTime
		if r.Outward != nil && r.Outward.MinDate != nil && r.Outward.Monday != nil && r.Outward.Monday.MinTime != nil {
			dateTimeStr := fmt.Sprintf("%sT%s", *r.Outward.MinDate, *r.Outward.Monday.MinTime)
			parsedTime, err := time.Parse("2006-01-02T15:04:05", dateTimeStr)
			if err != nil {
				log.Error().Err(err).Str("datetime", dateTimeStr).Msg("error parsing RDEX datetime")
				pickupDatetime = ocss.OCSSTime(departureDate)
			} else {
				pickupDatetime = ocss.OCSSTime(parsedTime)
			}
		} else {
			pickupDatetime = ocss.OCSSTime(departureDate)
		}

		// Get driver alias
		driverAlias := "Utilisateur RDEX"
		if r.Driver != nil && r.Driver.Alias != nil {
			driverAlias = *r.Driver.Alias
		}

		// Convert duration from seconds to duration
		var duration *time.Duration
		if r.Duration != nil {
			d := time.Duration(*r.Duration) * time.Second
			duration = &d
		}

		// Parse coordinates from string to float64
		var fromLat, fromLng, toLat, toLng float64
		if r.From != nil && r.From.Latitude != nil && r.From.Longitude != nil {
			fromLat, _ = strconv.ParseFloat(*r.From.Latitude, 64)
			fromLng, _ = strconv.ParseFloat(*r.From.Longitude, 64)
		}
		if r.To != nil && r.To.Latitude != nil && r.To.Longitude != nil {
			toLat, _ = strconv.ParseFloat(*r.To.Latitude, 64)
			toLng, _ = strconv.ParseFloat(*r.To.Longitude, 64)
		}

		// Build pickup and drop addresses from RDEX waypoint data
		var pickupAddress, dropAddress *string
		if r.From != nil {
			if r.From.Address != nil {
				pickupAddress = r.From.Address
			} else if r.From.City != nil {
				pickupAddress = r.From.City
			}
		}
		if r.To != nil {
			if r.To.Address != nil {
				dropAddress = r.To.Address
			} else if r.To.City != nil {
				dropAddress = r.To.City
			}
		}

		// Get available seats from driver
		var availableSeats *int64
		if r.Driver.Seats != nil {
			availableSeats = r.Driver.Seats
		}

		// Convert UUID to string for ID
		var uuidStr *string
		if r.UUID != nil {
			s := fmt.Sprintf("%d", *r.UUID)
			uuidStr = &s
		}

		// Build the driver journey
		driverJourney := ocss.DriverJourney{
			DriverTrip: ocss.DriverTrip{
				Driver: ocss.User{
					ID:       uuid.NewString(),
					Operator: api.OperatorName,
					Alias:    driverAlias,
				},
				Trip: ocss.Trip{
					Operator:               api.OperatorName,
					PassengerPickupLat:     fromLat,
					PassengerPickupLng:     fromLng,
					PassengerDropLat:       toLat,
					PassengerDropLng:       toLng,
					PassengerPickupAddress: pickupAddress,
					PassengerDropAddress:   dropAddress,
					Duration:               nilCheck(duration),
					Distance:               r.Distance,
					// JourneyPolyline is not provided by RDEX standard
				},
			},
			JourneySchedule: ocss.JourneySchedule{
				ID:                  uuidStr,
				PassengerPickupDate: pickupDatetime,
				WebUrl:              r.URL,
			},
			AvailableSteats: availableSeats,
			Price:           price,
		}
		journeys = append(journeys, driverJourney)
	}

	log.Info().
		Str("operator", api.OperatorId).
		Int("filtered_journeys_count", len(journeys)).
		Msg("RDEX GetDriverJourneys completed")

	return journeys, nil
}

func (api *RDEXCarpoolAPI) GetPassengerJourneys(
	departureLat float64,
	departureLng float64,
	arrivalLat float64,
	arrivalLng float64,
	departureDate time.Time,
	timeDelta *time.Duration,
	departureRadius int64,
	arrivalRadius int64,
	count int64,
) ([]ocss.PassengerJourney, error) {
	return nil, errors.New("not implemented")
}

func rdexSearch(baseURL string, publicKey string, privateKey string, departureLat float64, departureLng float64, arrivalLat float64, arrivalLng float64, minDate time.Time, maxDate time.Time, isDriver bool) ([]RDEXJourney, error) {
	// Build query parameters
	params := url.Values{}

	// Set driver or passenger state based on search type
	if isDriver {
		params.Add("p[driver][state]", "1")
		params.Add("p[passenger][state]", "0")
	} else {
		params.Add("p[driver][state]", "0")
		params.Add("p[passenger][state]", "1")
	}

	// Add geographic coordinates
	params.Add("p[from][latitude]", fmt.Sprintf("%f", departureLat))
	params.Add("p[from][longitude]", fmt.Sprintf("%f", departureLng))
	params.Add("p[to][latitude]", fmt.Sprintf("%f", arrivalLat))
	params.Add("p[to][longitude]", fmt.Sprintf("%f", arrivalLng))

	// Add date range
	params.Add("p[outward][mindate]", minDate.Format("2006-01-02"))
	params.Add("p[outward][maxdate]", maxDate.Format("2006-01-02"))

	// Set to punctual frequency
	params.Add("frequency", "punctual")

	// Add timestamp
	timestamp := strconv.FormatInt(time.Now().Unix(), 10)
	params.Add("timestamp", timestamp)

	// Add API key
	params.Add("apikey", publicKey)

	// Calculate signature using HMAC-SHA256
	signature := calculateRDEXSignature(params, privateKey)
	params.Add("signature", signature)

	// Build final URL
	finalURL := baseURL + "?" + params.Encode()

	log.Debug().
		Str("url", finalURL).
		Str("public_key", publicKey).
		Bool("is_driver", isDriver).
		Msg("RDEX API request")

	req, err := http.NewRequest("GET", finalURL, nil)
	if err != nil {
		log.Error().Err(err).Msg("new request issue")
		return nil, err
	}
	req.Header.Set("Content-Type", "application/json")

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Error().Err(err).Str("url", baseURL).Msg("error in RDEX request")
		return nil, err
	}
	defer resp.Body.Close()

	log.Debug().
		Int("status_code", resp.StatusCode).
		Str("status", resp.Status).
		Msg("RDEX API response received")

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		log.Error().
			Int("status", resp.StatusCode).
			Bytes("body", body).
			Str("url", baseURL).
			Msg("RDEX API returned non-200 status")
		return nil, fmt.Errorf("RDEX API returned status %d", resp.StatusCode)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		log.Error().Err(err).Msg("error reading response body")
		return nil, err
	}

	log.Debug().
		Str("response_body", string(body)).
		Msg("RDEX API raw response")

	var wrappedJourneys []RDEXJourneysResponse
	err = json.Unmarshal(body, &wrappedJourneys)
	if err != nil {
		log.Error().
			Err(err).
			Str("resp_body", string(body)).
			Any("status", resp.Status).
			Str("url", baseURL).
			Msg("cannot parse json response from RDEX API")
		return nil, err
	}

	// Unwrap the journeys from the response structure
	journeys := make([]RDEXJourney, 0, len(wrappedJourneys))
	for _, wrapped := range wrappedJourneys {
		journeys = append(journeys, wrapped.Journeys)
	}

	log.Debug().
		Int("journeys_count", len(journeys)).
		Msg("RDEX API response parsed successfully")

	return journeys, nil
}

// calculateRDEXSignature computes the HMAC-SHA256 signature for RDEX authentication
func calculateRDEXSignature(params url.Values, privateKey string) string {
	// Get all parameter keys and sort them alphabetically
	keys := make([]string, 0, len(params))
	for key := range params {
		keys = append(keys, key)
	}
	sort.Strings(keys)

	// Build the string to sign by concatenating sorted key=value pairs
	var signatureData string
	for _, key := range keys {
		values := params[key]
		for _, value := range values {
			signatureData += key + "=" + value
		}
	}

	log.Debug().
		Str("signature_data", signatureData).
		Msg("RDEX signature calculation")

	// Calculate HMAC-SHA256
	h := hmac.New(sha256.New, []byte(privateKey))
	h.Write([]byte(signatureData))
	signature := hex.EncodeToString(h.Sum(nil))

	return signature
}