package main
import (
"bytes"
"context"
"time"
"git.dev.alexdunmow.com/block/core/blocks"
"git.dev.alexdunmow.com/block/core/settings"
)
// renderSettings is the SettingsManager available to CalcomBookingFunc, which
// renders during the public page pipeline where no HTTP request (and thus no
// visitor timezone) exists. Set once by NewCalcomRouter when the plugin's HTTP
// routes are mounted at startup — before any page render. Nil in editor-only
// or test contexts, where the grid falls back to the server clock.
var renderSettings *SettingsManager
// BookingConfig holds the configuration for rendering the booking widget
type BookingConfig struct {
BlockID string
Username string
EventTypeSlug string
Title string
Description string
ShowTimezone bool
WeeksToShow int
WeekStart string // YYYY-MM-DD — first date in the current grid window
Today string // YYYY-MM-DD — today in the resolved timezone, for past-clamping
TimeZone string // IANA name shown in the "All times shown in" label
RangeLabel string // e.g. "May 27 – Jun 10, 2026" — populated by handler
CanGoBack bool // false when the window starts today (no point going earlier)
Dates []DateCell
// UnavailableMessage is the admin-authored copy shown when an online booking
// can't be completed for a non-fixable reason (Tier-2). Emitted as a hidden
// form input so the POST /book handler can read it back; defaults to
// DefaultUnavailableMessage when the admin leaves it blank.
UnavailableMessage string
}
// DateCell represents a single date in the calendar grid
type DateCell struct {
Date string // YYYY-MM-DD format
DayOfMonth string // e.g., "15"
DayOfWeek string // e.g., "Mon"
IsToday bool
IsPast bool
IsSelected bool // server-rendered selected state — set by HandleGetSlots
}
// CalcomBookingFunc renders the Cal.com booking widget
func CalcomBookingFunc(ctx context.Context, content map[string]any) string {
// Extract block ID from context or content
blockID := settings.GetStringOr(content, "_block_id", "")
if blockID == "" {
// Generate a simple ID if not provided
blockID = "calcom-" + time.Now().Format("150405")
}
config := BookingConfig{
BlockID: blockID,
Username: settings.GetStringOr(content, "username", ""),
EventTypeSlug: settings.GetStringOr(content, "eventTypeSlug", ""),
Title: settings.GetStringOr(content, "title", ""),
Description: settings.GetStringOr(content, "description", ""),
ShowTimezone: settings.GetBoolOr(content, "showTimezone", true),
WeeksToShow: settings.GetIntOr(content, "weeksToShow", 2),
UnavailableMessage: settings.GetStringOr(content, "unavailableMessage", DefaultUnavailableMessage),
}
// Check for missing required configuration
if config.Username == "" || config.EventTypeSlug == "" {
if blocks.IsEditor(ctx) {
return renderEditorPlaceholder()
}
return renderConfigError()
}
// Generate date grid for the calendar — initial window starts today on
// the MEETING's calendar: the cached event timezone when warm (filled by
// the first HTMX hit against the plugin endpoints), else the site
// Localization setting. Page render never blocks on a Cal.com round-trip.
// Without this, a container running UTC starts the grid on yesterday's
// date for a Perth schedule until 08:00 AWST.
loc, tzName := time.UTC, "UTC"
if renderSettings != nil {
loc, tzName = renderSettings.resolveLocation(ctx, peekEventTZ(config.Username, config.EventTypeSlug))
}
now := time.Now().In(loc)
today := now.Format("2006-01-02")
config.WeekStart = today
config.Today = today
config.TimeZone = tzName
config.Dates = generateDateGridFrom(now, config.WeeksToShow, today)
config.RangeLabel = formatRangeLabel(now, config.WeeksToShow)
config.CanGoBack = false // initial window is already at today
// Render the booking widget
var buf bytes.Buffer
if err := CalcomBookingWidget(config).Render(ctx, &buf); err != nil {
return renderError("Failed to render booking widget: " + err.Error())
}
return buf.String()
}
// formatRangeLabel renders the human-readable label for the date grid header,
// e.g. "May 27 – Jun 10, 2026". If start and end fall in the same month, the
// label collapses to "May 27 – 31, 2026".
func formatRangeLabel(start time.Time, weeks int) string {
if weeks <= 0 {
weeks = 1
}
end := start.AddDate(0, 0, weeks*7-1)
if start.Year() == end.Year() && start.Month() == end.Month() {
return start.Format("Jan 2") + " – " + end.Format("2, 2006")
}
if start.Year() == end.Year() {
return start.Format("Jan 2") + " – " + end.Format("Jan 2, 2006")
}
return start.Format("Jan 2, 2006") + " – " + end.Format("Jan 2, 2006")
}
// prevWeekStart returns the YYYY-MM-DD string for the previous date-grid
// window — weeks*7 days before the current weekStart, but clamped to today
// (the visitor can't book in the past). Used by the date-grid prev button.
// today is the YYYY-MM-DD date in the resolved timezone (BookingConfig.Today)
// — not the server clock's, which can be a day behind the visitor's.
func prevWeekStart(currentStart string, weeks int, today string) string {
if weeks <= 0 {
weeks = 1
}
t, err := time.Parse("2006-01-02", currentStart)
if err != nil || today > currentStart {
return today
}
prev := t.AddDate(0, 0, -weeks*7)
if prev.Format("2006-01-02") < today {
return today
}
return prev.Format("2006-01-02")
}
// nextWeekStart returns the YYYY-MM-DD string for the next date-grid window —
// weeks*7 days after the current weekStart.
func nextWeekStart(currentStart string, weeks int) string {
if weeks <= 0 {
weeks = 1
}
t, err := time.Parse("2006-01-02", currentStart)
if err != nil {
t = time.Now()
}
return t.AddDate(0, 0, weeks*7).Format("2006-01-02")
}
// generateDateGridFrom produces `weeks*7` consecutive day cells starting at
// `start`. Days strictly before `today` (YYYY-MM-DD in the resolved timezone)
// are flagged IsPast so the templ can render them disabled.
func generateDateGridFrom(start time.Time, weeks int, today string) []DateCell {
if weeks <= 0 {
weeks = 1
}
dates := make([]DateCell, 0, weeks*7)
for i := 0; i < weeks*7; i++ {
date := start.AddDate(0, 0, i)
dateStr := date.Format("2006-01-02")
dates = append(dates, DateCell{
Date: dateStr,
DayOfMonth: date.Format("2"),
DayOfWeek: date.Format("Mon"),
IsToday: dateStr == today,
IsPast: dateStr < today,
})
}
return dates
}
// leadingBlanks returns how many empty spacer cells must precede the first
// date so it lands under its weekday column header in the 7-column grid
// (Sun = column 1). Without these, a window starting mid-week pours into
// column 1 and every date renders under the wrong weekday — the bidbuddy
// "tapped Tue, got Friday" incident.
func leadingBlanks(dates []DateCell) int {
if len(dates) == 0 {
return 0
}
t, err := time.Parse("2006-01-02", dates[0].Date)
if err != nil {
return 0
}
return int(t.Weekday())
}
func renderEditorPlaceholder() string {
return `
`
}
// inputTypeFor maps a Cal.com bookingField type to an HTML value.
// Unknown types fall through to `text`.
func inputTypeFor(t string) string {
switch t {
case "email":
return "email"
case "phone":
return "tel"
case "number":
return "number"
default:
return "text"
}
}