package blocks

import (
	"fmt"
	"html"
)

// MediaValue represents a rich media object for template substitution.
// Implements fmt.Stringer to render a full <img> tag when used directly.
type MediaValue struct {
	Src      string // Full URL path (e.g., "/media/uuid/webp.webp")
	Alt      string // Alt text from media library
	Filename string // Original filename
	Width    int    // Image width in pixels
	Height   int    // Image height in pixels
}

// String renders the default <img> tag representation.
func (m MediaValue) String() string {
	attrs := fmt.Sprintf(`src="%s" alt="%s" class="w-full h-auto"`,
		html.EscapeString(m.Src),
		html.EscapeString(m.Alt))
	if m.Width > 0 && m.Height > 0 {
		attrs += fmt.Sprintf(` width="%d" height="%d"`, m.Width, m.Height)
	}
	return fmt.Sprintf(`<img %s>`, attrs)
}

// RenderWithClass renders the <img> tag with custom CSS classes.
func (m MediaValue) RenderWithClass(class string) string {
	attrs := fmt.Sprintf(`src="%s" alt="%s" class="%s"`,
		html.EscapeString(m.Src),
		html.EscapeString(m.Alt),
		html.EscapeString(class))
	if m.Width > 0 && m.Height > 0 {
		attrs += fmt.Sprintf(` width="%d" height="%d"`, m.Width, m.Height)
	}
	return fmt.Sprintf(`<img %s>`, attrs)
}

// TemplateRenderer is the interface for rendering pongo2/Jinja2-style templates.
// The CMS registers an implementation at startup.
type TemplateRenderer interface {
	RenderTemplate(tmpl string, data map[string]any) (string, error)
	ProcessIcons(html string) string
}

// templateRenderer holds the registered template renderer.
var templateRenderer TemplateRenderer

// RegisterTemplateRenderer sets the global template renderer.
// Called by the CMS at startup to provide pongo2 rendering.
func RegisterTemplateRenderer(r TemplateRenderer) {
	templateRenderer = r
}

// RenderTemplate renders a pongo2/Jinja2-style template string with the given data.
// Returns the rendered HTML or an error. Falls back to a no-op if no renderer is registered.
func RenderTemplate(tmpl string, data map[string]any) (string, error) {
	if templateRenderer == nil {
		// No renderer registered — return template as-is (no variable substitution)
		return tmpl, nil
	}
	return templateRenderer.RenderTemplate(tmpl, data)
}

// ProcessIcons processes ::pack:name:: icon syntax in HTML.
// Returns the HTML with icons replaced, or the original if no renderer is registered.
func ProcessIcons(htmlStr string) string {
	if templateRenderer == nil {
		return htmlStr
	}
	return templateRenderer.ProcessIcons(htmlStr)
}