package controllers

import (
	"os"
	"strings"

	"doormile/constants"
	"doormile/db"
	"doormile/internal/cxstage"
	"doormile/models"
	"doormile/utils"

	"github.com/gofiber/fiber/v2"
)

// QA support — §11 of the deliverables.
//
// "A way to force a booking to any stage on staging. Every tracking state must
// be reachable for QA — this is what lets us delete the debug stepper."
//
// The customer app currently walks its tracking screen through a hardcoded
// stepper because no real backend could produce those states on demand.
// Reaching out_for_delivery honestly needs a rider to accept, drive, weigh a
// parcel, hand it to a hub and start a delivery run — which is not something
// design QA can do before every screenshot.
//
// This endpoint is hard-gated. It refuses outright when ENV is production, and
// it additionally requires CX_ALLOW_STAGE_OVERRIDE to be set: two independent
// switches, because one of them being wrong on a production deploy would hand
// anyone with a customer token the ability to mark their own parcel delivered.

// cxStageOverrideEnabled reports whether the QA stage override may run at all.
func cxStageOverrideEnabled() bool {
	if strings.EqualFold(strings.TrimSpace(os.Getenv("ENV")), "production") {
		return false
	}
	return strings.EqualFold(strings.TrimSpace(os.Getenv("CX_ALLOW_STAGE_OVERRIDE")), "true")
}

// ForceCxStage drives a booking to an arbitrary stage on staging.
//
// It writes through the same cxstage recorder every real transition uses, so
// what QA sees is the real projection over real event rows — not a special
// rendering path that could pass while the production one is broken.
func ForceCxStage(c *fiber.Ctx) error {
	if !cxStageOverrideEnabled() {
		return utils.CxNotFound(c, "Not available")
	}

	customerID := c.Locals("userid").(int)
	reference := strings.TrimSpace(c.Params("reference"))

	var req struct {
		Stage string `json:"stage"`
		// Reason is recorded on the audit row so a forced transition is
		// distinguishable from a real one forever after. A staging database
		// that gets promoted, or an export read months later, must not present
		// invented history as observed history.
		Reason string `json:"reason"`
	}
	if err := c.BodyParser(&req); err != nil {
		return utils.CxBadRequest(c, "We could not read that request")
	}

	stage := strings.TrimSpace(req.Stage)
	if constants.CxStageRank(stage) < 0 {
		return utils.CxBadRequest(c, "Unknown stage")
	}

	booking, err := cxLoadBooking(customerID, reference)
	if err != nil {
		return utils.CxNotFound(c, "We could not find that pickup")
	}

	var destinations []models.BookingDestination
	if err := db.DB.Where("bookingid = ?", booking.Bookingid).
		Order("seq ASC").Find(&destinations).Error; err != nil {
		utils.Error("ForceCxStage: destination query failed", "booking_id", booking.Bookingid, "error", err)
		return utils.CxInternal(c)
	}

	reason := strings.TrimSpace(req.Reason)
	if reason == "" {
		reason = "forced on staging for QA"
	}

	tx := db.DB.Begin()

	// Walk every stage up to the target rather than jumping. A timeline with a
	// hole in it is not a state the production flow can produce, so testing
	// against one proves nothing about the screen that renders it.
	for _, s := range []string{
		constants.CxStageBooked, constants.CxStageAssigned, constants.CxStageOnTheWay,
		constants.CxStageArrived, constants.CxStagePickedUp, constants.CxStageOrderCreated,
		constants.CxStageInTransit, constants.CxStageOutForDelivery, constants.CxStageDelivered,
	} {
		if constants.CxStageRank(s) > constants.CxStageRank(stage) {
			break
		}

		perOrder := constants.CxStageRank(s) >= constants.CxStageOrder[constants.CxStageInTransit]
		if perOrder && len(destinations) > 0 {
			for i := range destinations {
				id := destinations[i].Bookingdestinationid
				if err := cxstage.Record(tx, cxstage.Event{
					BookingID:     booking.Bookingid,
					DestinationID: &id,
					Stage:         s,
					ActorType:     constants.CxActorOps,
					ActorID:       &customerID,
					Source:        "POST /customer/ops/bookings/{reference}/stage",
					Remarks:       reason,
				}); err != nil {
					tx.Rollback()
					utils.Error("ForceCxStage: record failed", "booking_id", booking.Bookingid, "stage", s, "error", err)
					return utils.CxInternal(c)
				}
			}
			continue
		}

		if err := cxstage.Record(tx, cxstage.Event{
			BookingID: booking.Bookingid,
			Stage:     s,
			ActorType: constants.CxActorOps,
			ActorID:   &customerID,
			Source:    "POST /customer/ops/bookings/{reference}/stage",
			Remarks:   reason,
		}); err != nil {
			tx.Rollback()
			utils.Error("ForceCxStage: record failed", "booking_id", booking.Bookingid, "stage", s, "error", err)
			return utils.CxInternal(c)
		}
	}

	// Tracking numbers exist from order_created onward, so a forced booking
	// past that point needs them or the orders render with a null trackingId
	// and the deep-link path cannot be tested at all.
	if constants.CxStageRank(stage) >= constants.CxStageOrder[constants.CxStageOrderCreated] {
		for i := range destinations {
			if destinations[i].Trackingno != "" {
				continue
			}
			if err := tx.Model(&models.BookingDestination{}).
				Where("bookingdestinationid = ?", destinations[i].Bookingdestinationid).
				Update("trackingno", generateTrackingNo()).Error; err != nil {
				tx.Rollback()
				utils.Error("ForceCxStage: could not mint tracking number", "booking_id", booking.Bookingid, "error", err)
				return utils.CxInternal(c)
			}
		}
	}

	if err := tx.Commit().Error; err != nil {
		utils.Error("ForceCxStage: commit failed", "booking_id", booking.Bookingid, "error", err)
		return utils.CxInternal(c)
	}

	return cxRespondWithBooking(c, booking.Bookingid, fiber.StatusOK)
}