mermaid-server/internal/diagram.go

package internal

import (
	"crypto/md5"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"strings"
	"sync"
	"time"
)

// NewDiagram returns a new diagram.
func NewDiagram(description []byte, imgType string) *Diagram {
	// Debug: Log what we received
	fmt.Printf("DEBUG: Received %d bytes\n", len(description))
	fmt.Printf("DEBUG: Raw bytes: %q\n", string(description))
	fmt.Printf("DEBUG: Contains newlines: %t\n", strings.Contains(string(description), "\n"))
	
	trimmed := strings.TrimSpace(string(description))
	fmt.Printf("DEBUG: After TrimSpace: %q\n", trimmed)
	fmt.Printf("DEBUG: Still contains newlines: %t\n", strings.Contains(trimmed, "\n"))
	
	// Decode NEWLINE markers back to actual newlines for complex diagrams
	if strings.Contains(trimmed, " NEWLINE ") {
		trimmed = strings.ReplaceAll(trimmed, " NEWLINE ", "\n")
		fmt.Printf("DEBUG: After NEWLINE decoding: %q\n", trimmed)
		fmt.Printf("DEBUG: Now contains newlines: %t\n", strings.Contains(trimmed, "\n"))
	}
	
	// Decode pipe separators back to newlines for quadrant charts
	if strings.Contains(trimmed, " | ") {
		trimmed = strings.ReplaceAll(trimmed, " | ", "\n")
		fmt.Printf("DEBUG: After pipe decoding: %q\n", trimmed)
		fmt.Printf("DEBUG: Now contains newlines: %t\n", strings.Contains(trimmed, "\n"))
	}
	
	return &Diagram{
		description: []byte(trimmed),
		lastTouched: time.Now(),
		mu:          &sync.RWMutex{},
		imgType:     imgType,
	}
}

// Diagram represents a single diagram.
type Diagram struct {
	// id is the ID of the Diagram
	id string
	// description is the description of the diagram.
	description []byte
	// Output is the filepath to the output file.
	Output string
	// mu is a mutex to protect the last touched value.
	mu *sync.RWMutex
	// lastTouched is the time that the diagram was last used.
	lastTouched time.Time
	// the type of image to generate svg or png
	imgType string
}

// Touch updates the last touched time of the diagram.
func (d *Diagram) Touch() {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.lastTouched = time.Now()
}

// TouchedInDuration returns true if the diagram has been touched in the given duration.
func (d *Diagram) TouchedInDuration(duration time.Duration) bool {
	d.mu.Lock()
	defer d.mu.Unlock()
	return time.Now().Add(-duration).Before(d.lastTouched)
}

// ID returns an ID for the diagram.
// The ID is set from the diagram description.
func (d *Diagram) ID() (string, error) {
	if d.id != "" {
		return d.id, nil
	}

	encoded := base64.StdEncoding.EncodeToString(d.description)
	hash := md5.Sum([]byte(encoded))
	d.id = hex.EncodeToString(hash[:]) + d.imgType

	return d.id, nil
}

// Description returns the diagram description.
func (d *Diagram) Description() []byte {
	return d.description
}

// Description returns the diagram description.
func (d *Diagram) WithDescription(description []byte) *Diagram {
	d.description = description
	d.id = ""
	return d
}