feat: add file upload for materials (PDF/DOCX) with ingestion pipeline

internal/ingestion/parse_pdf.go

@@ -0,0 +1,74 @@
+package ingestion
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/pdfcpu/pdfcpu/pkg/api"
+	"github.com/pdfcpu/pdfcpu/pkg/pdfcpu/model"
+)
+
+func ParsePDF(path string) (string, error) {
+	ctx, err := api.ReadContextFile(path)
+	if err != nil {
+		return "", err
+	}
+
+	tmpDir, err := os.MkdirTemp("", "pdf-extract-*")
+	if err != nil {
+		return "", err
+	}
+	defer os.RemoveAll(tmpDir)
+
+	conf := model.NewDefaultConfiguration()
+	if err := api.ExtractContentFile(path, tmpDir, nil, conf); err != nil {
+		return "", err
+	}
+
+	var buf strings.Builder
+	entries, err := os.ReadDir(tmpDir)
+	if err != nil {
+		return "", err
+	}
+
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+		content, err := os.ReadFile(filepath.Join(tmpDir, entry.Name()))
+		if err != nil {
+			return "", fmt.Errorf("read extracted content %s: %w", entry.Name(), err)
+		}
+		buf.WriteString(string(content))
+		buf.WriteString("\n")
+	}
+
+	if buf.Len() == 0 {
+		content, err := extractPageText(ctx)
+		if err == nil {
+			buf.WriteString(content)
+		}
+	}
+
+	return buf.String(), nil
+}
+
+func extractPageText(ctx *model.Context) (string, error) {
+	var buf strings.Builder
+	for i := 1; i <= ctx.PageCount; i++ {
+		r, err := api.ExtractPage(ctx, i)
+		if err != nil {
+			continue
+		}
+		data, err := io.ReadAll(r)
+		if err != nil {
+			continue
+		}
+		buf.Write(data)
+		buf.WriteString("\n")
+	}
+	return buf.String(), nil
+}