package api

import (
	"encoding/json"
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"

	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
	"gitea.stevedudenhoeffer.com/steve/pansy/internal/service"
)

// plantingCreateRequest is the body for POST /objects/:id/plantings. x/y are in
// the object's local frame (origin at object center); count omitted = derived;
// plantedAt omitted = today.
type plantingCreateRequest struct {
	PlantID   int64   `json:"plantId" binding:"required"`
	XCM       float64 `json:"xCm"`
	YCM       float64 `json:"yCm"`
	RadiusCM  float64 `json:"radiusCm"`
	Count     *int    `json:"count"`
	Label     *string `json:"label"`
	PlantedAt *string `json:"plantedAt"`
	SeedLotID *int64  `json:"seedLotId"`
}

func (r plantingCreateRequest) toInput() service.PlantingInput {
	return service.PlantingInput{
		PlantID: r.PlantID, XCM: r.XCM, YCM: r.YCM, RadiusCM: r.RadiusCM,
		Count: r.Count, Label: r.Label, PlantedAt: r.PlantedAt, SeedLotID: r.SeedLotID,
	}
}

// plantingUpdateRequest is the body for PATCH /plantings/:id: every field
// optional (absent = unchanged) plus the required current version. The nullable
// fields are json.RawMessage so an explicit null (clear) is distinct from an
// absent field (unchanged) — e.g. `removedAt: "2026-07-01"` soft-removes and
// `removedAt: null` un-removes.
type plantingUpdateRequest struct {
	PlantID   *int64          `json:"plantId"`
	XCM       *float64        `json:"xCm"`
	YCM       *float64        `json:"yCm"`
	RadiusCM  *float64        `json:"radiusCm"`
	Count     json.RawMessage `json:"count"`
	Label     json.RawMessage `json:"label"`
	PlantedAt json.RawMessage `json:"plantedAt"`
	RemovedAt json.RawMessage `json:"removedAt"`
	SeedLotID json.RawMessage `json:"seedLotId"`
	Version   int64           `json:"version" binding:"required,min=1"`
}

func (r plantingUpdateRequest) toPatch() (service.PlantingPatch, error) {
	count, setCount, err := parseNullableInt(r.Count)
	if err != nil {
		return service.PlantingPatch{}, err
	}
	label, setLabel, err := parseNullableString(r.Label)
	if err != nil {
		return service.PlantingPatch{}, err
	}
	plantedAt, setPlantedAt, err := parseNullableString(r.PlantedAt)
	if err != nil {
		return service.PlantingPatch{}, err
	}
	seedLot, setSeedLot, err := parseNullable[int64](r.SeedLotID)
	if err != nil {
		return service.PlantingPatch{}, err
	}
	removedAt, setRemovedAt, err := parseNullableString(r.RemovedAt)
	if err != nil {
		return service.PlantingPatch{}, err
	}
	return service.PlantingPatch{
		PlantID: r.PlantID, XCM: r.XCM, YCM: r.YCM, RadiusCM: r.RadiusCM,
		SetCount: setCount, Count: count,
		SetLabel: setLabel, Label: label,
		SetPlantedAt: setPlantedAt, PlantedAt: plantedAt,
		SetRemovedAt: setRemovedAt, RemovedAt: removedAt,
		SetSeedLotID: setSeedLot, SeedLotID: seedLot,
	}, nil
}

func (h *handlers) createPlanting(c *gin.Context) {
	objectID, ok := parseIDParam(c, "id")
	if !ok {
		return
	}
	var req plantingCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "invalid planting: a plantId is required")
		return
	}
	p, err := h.svc.CreatePlanting(c.Request.Context(), mustActor(c).ID, objectID, req.toInput())
	if err != nil {
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusCreated, p)
}

func (h *handlers) updatePlanting(c *gin.Context) {
	id, ok := parseIDParam(c, "id")
	if !ok {
		return
	}
	var req plantingUpdateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "invalid update: a current version is required")
		return
	}
	patch, err := req.toPatch()
	if err != nil {
		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "invalid update payload")
		return
	}
	p, err := h.svc.UpdatePlanting(c.Request.Context(), mustActor(c).ID, id, patch, req.Version)
	if err != nil {
		if errors.Is(err, domain.ErrVersionConflict) {
			writeVersionConflict(c, p)
			return
		}
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusOK, p)
}

func (h *handlers) deletePlanting(c *gin.Context) {
	id, ok := parseIDParam(c, "id")
	if !ok {
		return
	}
	if err := h.svc.DeletePlanting(c.Request.Context(), mustActor(c).ID, id); err != nil {
		writeServiceError(c, err)
		return
	}
	c.Status(http.StatusNoContent)
}