package api

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"

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

// gardenFields is the shared mutable field set for the gardens endpoints.
// Dimensions are centimeters (the API is metric-only; imperial is a display
// concern). On create, omitted dimensions default server-side.
type gardenFields struct {
	Name     string  `json:"name" binding:"required"`
	WidthCM  float64 `json:"widthCm"`
	HeightCM float64 `json:"heightCm"`
	UnitPref string  `json:"unitPref"`
	Notes    string  `json:"notes"`
}

func (f gardenFields) toInput() service.GardenInput {
	return service.GardenInput{Name: f.Name, WidthCM: f.WidthCM, HeightCM: f.HeightCM, UnitPref: f.UnitPref, Notes: f.Notes}
}

// gardenCreateRequest / gardenUpdateRequest are the JSON bodies. Update adds a
// required current version (>= 1) for the optimistic-concurrency guard.
type gardenCreateRequest struct {
	gardenFields
}

type gardenUpdateRequest struct {
	gardenFields
	Version int64 `json:"version" binding:"required,min=1"`
}

// listGardens returns the actor's gardens as a JSON array (always an array,
// never null).
func (h *handlers) listGardens(c *gin.Context) {
	gardens, err := h.svc.ListGardens(c.Request.Context(), mustActor(c).ID)
	if err != nil {
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusOK, gardens)
}

func (h *handlers) createGarden(c *gin.Context) {
	var req gardenCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "a garden name is required")
		return
	}
	g, err := h.svc.CreateGarden(c.Request.Context(), mustActor(c).ID, req.toInput())
	if err != nil {
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusCreated, g)
}

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

func (h *handlers) updateGarden(c *gin.Context) {
	id, ok := parseIDParam(c, "id")
	if !ok {
		return
	}
	var req gardenUpdateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "name and a current version are required")
		return
	}
	g, err := h.svc.UpdateGarden(c.Request.Context(), mustActor(c).ID, id, req.toInput(), req.Version)
	if err != nil {
		// On a version conflict the service returns the current row so the client
		// can rebase; everything else is a plain error.
		if errors.Is(err, domain.ErrVersionConflict) {
			writeVersionConflict(c, g)
			return
		}
		writeServiceError(c, err)
		return
	}
	c.JSON(http.StatusOK, g)
}

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