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"
)

// objectCreateRequest is the body for POST /gardens/:id/objects. Dimensions are
// centimeters; the object is positioned by its center. Plantable/color/props are
// optional (plantable defaults by kind). props is any JSON value, stored as-is.
type objectCreateRequest struct {
	Kind        string          `json:"kind" binding:"required"`
	Name        string          `json:"name"`
	Shape       string          `json:"shape"`
	XCM         float64         `json:"xCm"`
	YCM         float64         `json:"yCm"`
	WidthCM     float64         `json:"widthCm"`
	HeightCM    float64         `json:"heightCm"`
	RotationDeg float64         `json:"rotationDeg"`
	ZIndex      int             `json:"zIndex"`
	Plantable   *bool           `json:"plantable"`
	Color       *string         `json:"color"`
	Props       json.RawMessage `json:"props"`
	Notes       string          `json:"notes"`
}

// objectUpdateRequest is the body for PATCH /objects/:id: every field optional
// (absent = unchanged), plus the required current version. Kind and shape are
// immutable and not accepted.
type objectUpdateRequest struct {
	Name        *string         `json:"name"`
	XCM         *float64        `json:"xCm"`
	YCM         *float64        `json:"yCm"`
	WidthCM     *float64        `json:"widthCm"`
	HeightCM    *float64        `json:"heightCm"`
	RotationDeg *float64        `json:"rotationDeg"`
	ZIndex      *int            `json:"zIndex"`
	Plantable   *bool           `json:"plantable"`
	Color       *string         `json:"color"`
	Props       json.RawMessage `json:"props"`
	Notes       *string         `json:"notes"`
	Version     int64           `json:"version" binding:"required,min=1"`
}

// propsFromRaw maps a JSON props value to the stored *string: a present, non-null
// value becomes its JSON text; absent or null becomes nil (leave/none).
func propsFromRaw(raw json.RawMessage) *string {
	if len(raw) == 0 || string(raw) == "null" {
		return nil
	}
	s := string(raw)
	return &s
}

func (h *handlers) createObject(c *gin.Context) {
	gardenID, ok := parseIDParam(c, "id")
	if !ok {
		return
	}
	var req objectCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "kind is required")
		return
	}
	o, err := h.svc.CreateObject(c.Request.Context(), mustActor(c).ID, gardenID, service.ObjectInput{
		Kind:        req.Kind,
		Name:        req.Name,
		Shape:       req.Shape,
		XCM:         req.XCM,
		YCM:         req.YCM,
		WidthCM:     req.WidthCM,
		HeightCM:    req.HeightCM,
		RotationDeg: req.RotationDeg,
		ZIndex:      req.ZIndex,
		Plantable:   req.Plantable,
		Color:       req.Color,
		Props:       propsFromRaw(req.Props),
		Notes:       req.Notes,
	})
	if err != nil {
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusCreated, o)
}

func (h *handlers) updateObject(c *gin.Context) {
	id, ok := parseIDParam(c, "id")
	if !ok {
		return
	}
	var req objectUpdateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "a current version is required")
		return
	}
	o, err := h.svc.UpdateObject(c.Request.Context(), mustActor(c).ID, id, service.ObjectPatch{
		Name:        req.Name,
		XCM:         req.XCM,
		YCM:         req.YCM,
		WidthCM:     req.WidthCM,
		HeightCM:    req.HeightCM,
		RotationDeg: req.RotationDeg,
		ZIndex:      req.ZIndex,
		Plantable:   req.Plantable,
		Color:       req.Color,
		Props:       propsFromRaw(req.Props),
		Notes:       req.Notes,
	}, req.Version)
	if err != nil {
		if errors.Is(err, domain.ErrVersionConflict) {
			writeVersionConflict(c, o)
			return
		}
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusOK, o)
}

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

func (h *handlers) gardenFull(c *gin.Context) {
	gardenID, ok := parseIDParam(c, "id")
	if !ok {
		return
	}
	full, err := h.svc.GardenFull(c.Request.Context(), mustActor(c).ID, gardenID)
	if err != nil {
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusOK, full)
}