package handlers

import (
	"net/http"
	"time"

	"github.com/breakpilot/school-service/internal/models"
	"github.com/gin-gonic/gin"
)

// ListCalendarHolidays returns OpenHolidaysAPI events for a region + range.
// Query params: ?region=DE-NI&from=2026-08-01&to=2027-07-31. If omitted,
// region falls back to the caller's saved config and the range to the
// current calendar year.
func (h *Handler) ListCalendarHolidays(c *gin.Context) {
	uid := getUserID(c)
	if uid == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}
	region := c.Query("region")
	if region == "" {
		cfg, err := h.calendarService.GetConfig(c.Request.Context(), uid)
		if err != nil || cfg == nil {
			respondError(c, http.StatusBadRequest, "region query param required (no saved config)")
			return
		}
		region = cfg.Bundesland
	}
	from := c.DefaultQuery("from", time.Now().Format("2006-01-02"))
	to := c.DefaultQuery("to", time.Now().AddDate(1, 0, 0).Format("2006-01-02"))

	events, err := h.calendarService.ListHolidays(c.Request.Context(), region, from, to)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to load holidays: "+err.Error())
		return
	}
	if events == nil {
		events = []models.PublicEvent{}
	}
	respondSuccess(c, events)
}

func (h *Handler) GetCalendarConfig(c *gin.Context) {
	uid := getUserID(c)
	if uid == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}
	cfg, err := h.calendarService.GetConfig(c.Request.Context(), uid)
	if err != nil {
		// No row → 200 with null so the wizard knows to prompt.
		respondSuccess(c, nil)
		return
	}
	respondSuccess(c, cfg)
}

func (h *Handler) UpsertCalendarConfig(c *gin.Context) {
	uid := getUserID(c)
	if uid == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}
	var req models.UpsertSchoolCalendarConfigRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
		return
	}
	cfg, err := h.calendarService.UpsertConfig(c.Request.Context(), uid, &req)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to save config: "+err.Error())
		return
	}
	respondCreated(c, cfg)
}

// ---------- School Events (Phase 9b) ----------

func (h *Handler) CreateSchoolEvent(c *gin.Context) {
	uid := getUserID(c)
	if uid == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}
	var req models.CreateSchoolEventRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
		return
	}
	ev, err := h.calendarService.CreateEvent(c.Request.Context(), uid, &req)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to create event: "+err.Error())
		return
	}
	respondCreated(c, ev)
}

func (h *Handler) ListSchoolEvents(c *gin.Context) {
	uid := getUserID(c)
	if uid == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}
	events, err := h.calendarService.ListEvents(c.Request.Context(), uid, c.Query("from"), c.Query("to"))
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to list events: "+err.Error())
		return
	}
	if events == nil {
		events = []models.SchoolEvent{}
	}
	respondSuccess(c, events)
}

func (h *Handler) DeleteSchoolEvent(c *gin.Context) {
	uid := getUserID(c)
	if uid == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}
	if err := h.calendarService.DeleteEvent(c.Request.Context(), c.Param("id"), uid); err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to delete event: "+err.Error())
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "Event deleted"})
}

func (h *Handler) RolloverSchoolYear(c *gin.Context) {
	uid := getUserID(c)
	if uid == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}
	var req models.SchoolYearRolloverRequest
	// Body is optional — empty defaults to next-Aug rollover.
	_ = c.ShouldBindJSON(&req)

	result, err := h.calendarService.RolloverSchoolYear(c.Request.Context(), uid, &req)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Rollover failed: "+err.Error())
		return
	}
	respondSuccess(c, result)
}