package main

import (
	"encoding/csv"
	"fmt"
	"net/http"
	"strconv"
	"strings"
)

// handleGenerateTokens creates volunteer_token values for all attendees that don't have one.
func (app *App) handleGenerateTokens(w http.ResponseWriter, r *http.Request) {
	count, err := app.generateTokensForAll()
	if err != nil {
		writeError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	writeJSON(w, map[string]any{"generated": count})
}

// handleExportTokenLinks streams a CSV download with token signup links,
// compatible with MailChimp / Zeffy bulk-send workflows.
func (app *App) handleExportTokenLinks(w http.ResponseWriter, r *http.Request) {
	attendees, err := app.listAttendees("", "", "")
	if err != nil {
		writeError(w, err.Error(), http.StatusInternalServerError)
		return
	}

	baseURL := app.baseURL
	if baseURL == "" {
		app.db.QueryRow(`SELECT value FROM config WHERE key = 'base_url'`).Scan(&baseURL)
	}
	baseURL = strings.TrimRight(baseURL, "/")

	w.Header().Set("Content-Type", "text/csv")
	w.Header().Set("Content-Disposition", `attachment; filename="volunteer-tokens.csv"`)
	wr := csv.NewWriter(w)
	wr.Write([]string{"Email Address", "First Name", "Token", "Signup Link"})
	for _, a := range attendees {
		if a.VolunteerToken == nil {
			continue
		}
		firstName := a.Name
		if parts := strings.Fields(a.Name); len(parts) > 0 {
			firstName = parts[0]
		}
		link := fmt.Sprintf("%s/#/v/%s", baseURL, *a.VolunteerToken)
		wr.Write([]string{a.Email, firstName, *a.VolunteerToken, link})
	}
	wr.Flush()
}

// handleEmailToken sends a token email to a single attendee.
func (app *App) handleEmailToken(w http.ResponseWriter, r *http.Request) {
	id, err := strconv.Atoi(r.PathValue("id"))
	if err != nil {
		writeError(w, "invalid id", http.StatusBadRequest)
		return
	}
	a, err := app.getAttendee(id)
	if err != nil || a == nil {
		writeError(w, "not found", http.StatusNotFound)
		return
	}
	if err := app.sendTokenEmail(*a); err != nil {
		writeError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	writeJSON(w, map[string]any{"ok": true})
}

// handleEmailAllTokens bulk-sends token emails to all attendees that have both a token and email.
func (app *App) handleEmailAllTokens(w http.ResponseWriter, r *http.Request) {
	attendees, err := app.listAttendees("", "", "")
	if err != nil {
		writeError(w, err.Error(), http.StatusInternalServerError)
		return
	}
	var sent, skipped int
	var errors []string
	for _, a := range attendees {
		if a.Email == "" || a.VolunteerToken == nil {
			skipped++
			continue
		}
		if err := app.sendTokenEmail(a); err != nil {
			errors = append(errors, fmt.Sprintf("%s: %v", a.Name, err))
			skipped++
		} else {
			sent++
		}
	}
	if errors == nil {
		errors = []string{}
	}
	writeJSON(w, map[string]any{"sent": sent, "skipped": skipped, "errors": errors})
}