package main

import (
	"errors"
	"net/http"
	"strconv"
)

// handleKioskGet returns the volunteer's profile, current shift assignments, and
// available open shifts in their department. Authenticated by volunteer token only —
// no JWT required.
func (app *App) handleKioskGet(w http.ResponseWriter, r *http.Request) {
	token := r.PathValue("token")
	a, err := app.getAttendeeByToken(token)
	if err != nil || a == nil {
		writeError(w, "not found", http.StatusNotFound)
		return
	}

	v, _ := app.getVolunteerByAttendeeID(a.ID)
	if v == nil {
		writeError(w, "no volunteer record linked to this token", http.StatusNotFound)
		return
	}

	assigned, _ := app.listShiftsForVolunteer(v.ID)
	if assigned == nil {
		assigned = []Shift{}
	}

	var available []Shift
	if v.DepartmentID != nil {
		available, _ = app.listOpenShiftsForDept(*v.DepartmentID)
	}
	if available == nil {
		available = []Shift{}
	}

	writeJSON(w, map[string]any{
		"volunteer": v,
		"shifts":    assigned,
		"available": available,
	})
}

// handleKioskClaim assigns the volunteer to a shift.
// Without ?force=true it returns 409 with conflicting shifts on overlap.
func (app *App) handleKioskClaim(w http.ResponseWriter, r *http.Request) {
	token := r.PathValue("token")
	shiftID, err := strconv.Atoi(r.PathValue("id"))
	if err != nil {
		writeError(w, "invalid shift id", http.StatusBadRequest)
		return
	}

	a, err := app.getAttendeeByToken(token)
	if err != nil || a == nil {
		writeError(w, "not found", http.StatusNotFound)
		return
	}
	v, _ := app.getVolunteerByAttendeeID(a.ID)
	if v == nil {
		writeError(w, "no volunteer linked to this token", http.StatusNotFound)
		return
	}

	force := r.URL.Query().Get("force") == "true"

	if !force {
		conflicts, err := app.checkShiftConflict(v.ID, shiftID)
		if err != nil {
			writeError(w, err.Error(), http.StatusInternalServerError)
			return
		}
		if len(conflicts) > 0 {
			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(http.StatusConflict)
			writeJSON(w, map[string]any{
				"conflict":           true,
				"conflicting_shifts": conflicts,
			})
			return
		}
	}

	shift, err := app.getShift(shiftID)
	if err != nil || shift == nil {
		writeError(w, "shift not found", http.StatusNotFound)
		return
	}

	if err := app.assignShiftWithCapacity(v.ID, shiftID, shift.Capacity); err != nil {
		if errors.Is(err, errShiftFull) {
			writeError(w, "shift is full", http.StatusConflict)
			return
		}
		writeError(w, err.Error(), http.StatusInternalServerError)
		return
	}

	app.handleKioskGet(w, r)
}

// handleKioskUnclaim removes the volunteer from a shift.
func (app *App) handleKioskUnclaim(w http.ResponseWriter, r *http.Request) {
	token := r.PathValue("token")
	shiftID, err := strconv.Atoi(r.PathValue("id"))
	if err != nil {
		writeError(w, "invalid shift id", http.StatusBadRequest)
		return
	}

	a, err := app.getAttendeeByToken(token)
	if err != nil || a == nil {
		writeError(w, "not found", http.StatusNotFound)
		return
	}
	v, _ := app.getVolunteerByAttendeeID(a.ID)
	if v == nil {
		writeError(w, "no volunteer linked to this token", http.StatusNotFound)
		return
	}

	if err := app.unassignShift(v.ID, shiftID); err != nil {
		writeError(w, err.Error(), http.StatusInternalServerError)
		return
	}

	app.handleKioskGet(w, r)
}