export: month calendar PDF (A4 landscape, Monday-first grid, feast name + gospel ref + liturgical colour per day); cli --calendar YYYY-MM; web /calendar + link; readings.GospelCitation; v0.23.0

1 files changed, 140 insertions, 0 deletions

diff --git a/internal/export/calendar.go b/internal/export/calendar.go
new file mode 100644
index 0000000..8828892
--- /dev/null
+++ b/internal/export/calendar.go
@@ -0,0 +1,140 @@
+package export
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+	"time"
+
+	"github.com/go-pdf/fpdf"
+)
+
+// CalendarDay is one day's entry in a month calendar: the day-of-month, the
+// celebration name, the gospel reference, and the liturgical colour (a name
+// like "white"/"green"/"violet"/"red"/"rose"; "" = uncoloured).
+type CalendarDay struct {
+	Day      int
+	Name     string
+	Citation string
+	Colour   string
+}
+
+// liturgicalRGB maps a normalized liturgical colour to a soft printable RGB for
+// the coloured strip atop each calendar cell.
+var liturgicalRGB = map[string][3]int{
+	"white":  {235, 235, 230},
+	"green":  {90, 160, 90},
+	"violet": {130, 90, 165},
+	"red":    {200, 70, 70},
+	"rose":   {235, 165, 195},
+}
+
+// weekdayAbbr are the Monday-first column headers per UI language.
+var weekdayAbbr = map[string][7]string{
+	"en": {"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"},
+	"pl": {"Pn", "Wt", "Śr", "Cz", "Pt", "So", "Nd"},
+}
+
+// truncate shortens s to at most n runes, appending "…" when it had to cut.
+func truncate(s string, n int) string {
+	r := []rune(s)
+	if len(r) <= n {
+		return s
+	}
+	if n < 1 {
+		return ""
+	}
+	return string(r[:n-1]) + "…"
+}
+
+// CalendarPDF renders a printable A4 landscape month calendar: a Monday-first
+// grid where each day shows its number, a coloured liturgical strip, the
+// celebration name and the gospel reference. lectionary/lang label the header;
+// days is the month's CalendarDay entries (day 1..N).
+func CalendarPDF(year, month int, days []CalendarDay, lectionary, lang string) ([]byte, error) {
+	if len(days) == 0 {
+		return nil, fmt.Errorf("export: empty month")
+	}
+
+	pdf := fpdf.New("L", "mm", "A4", "")
+	pdf.AddUTF8FontFromBytes(fontFamily, "", fontRegular)
+	pdf.AddUTF8FontFromBytes(fontFamily, "B", fontBold)
+	const margin = 10.0
+	pdf.SetMargins(margin, margin, margin)
+	pdf.SetAutoPageBreak(false, margin)
+	pdf.AddPage()
+	pw, ph := pdf.GetPageSize()
+
+	lect := lectionary
+	if lect == "new" {
+		lect = "modern"
+	}
+	pdf.SetFont(fontFamily, "B", 16)
+	pdf.CellFormat(0, 9, fmt.Sprintf("%s %d — %s", time.Month(month).String(), year, lect), "", 1, "L", false, 0, "")
+
+	const gridY0 = 22.0
+	const weekdayH = 6.0
+	const cols = 7
+	cellW := (pw - 2*margin) / float64(cols)
+
+	hdr := weekdayAbbr[lang]
+	if hdr[0] == "" {
+		hdr = weekdayAbbr["en"]
+	}
+	pdf.SetFont(fontFamily, "B", 9)
+	for i, h := range hdr {
+		pdf.SetXY(margin+float64(i)*cellW, gridY0)
+		pdf.CellFormat(cellW, weekdayH, h, "", 0, "C", false, 0, "")
+	}
+	gridY := gridY0 + weekdayH
+
+	byDay := map[int]CalendarDay{}
+	daysInMonth := 0
+	for _, d := range days {
+		byDay[d.Day] = d
+		if d.Day > daysInMonth {
+			daysInMonth = d.Day
+		}
+	}
+	first := time.Date(year, time.Month(month), 1, 0, 0, 0, 0, time.UTC)
+	firstCol := (int(first.Weekday()) + 6) % 7 // Monday = 0
+	rows := (firstCol + daysInMonth + 6) / 7
+	cellH := (ph - gridY - margin) / float64(rows)
+
+	// per-cell text budgets (approximate, keeps content inside the cell)
+	nameChars := int((cellW - 3) / 1.35)
+	for day := 1; day <= daysInMonth; day++ {
+		idx := firstCol + day - 1
+		x := margin + float64(idx%7)*cellW
+		y := gridY + float64(idx/7)*cellH
+
+		pdf.SetDrawColor(150, 150, 150)
+		pdf.Rect(x, y, cellW, cellH, "D")
+
+		cd := byDay[day]
+		if rgb, ok := liturgicalRGB[cd.Colour]; ok {
+			pdf.SetFillColor(rgb[0], rgb[1], rgb[2])
+			pdf.Rect(x, y, cellW, 2.4, "F")
+		}
+
+		pdf.SetTextColor(0, 0, 0)
+		pdf.SetFont(fontFamily, "B", 10)
+		pdf.SetXY(x+1.5, y+3)
+		pdf.CellFormat(cellW-3, 5, strconv.Itoa(day), "", 0, "L", false, 0, "")
+
+		pdf.SetFont(fontFamily, "", 7)
+		pdf.SetXY(x+1.5, y+8.5)
+		pdf.MultiCell(cellW-3, 3.1, truncate(cd.Name, nameChars*2), "", "L", false)
+		if cd.Citation != "" {
+			pdf.SetX(x + 1.5)
+			pdf.SetFont(fontFamily, "B", 7)
+			pdf.MultiCell(cellW-3, 3.1, truncate(cd.Citation, nameChars), "", "L", false)
+		}
+	}
+
+	var buf bytes.Buffer
+	if err := pdf.Output(&buf); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}