package builtin

import (
	"context"
	"fmt"
	"html"
	"maps"
	"regexp"
	"strings"

	"git.dev.alexdunmow.com/block/core/blocks"
	"github.com/google/uuid"
)

var HTMLBlockMeta = blocks.BlockMeta{
	Key:         "html",
	Title:       "HTML",
	Description: "Raw HTML content with template variable support",
	Category:    blocks.CategoryContent,
}

var mediaURLRegex = regexp.MustCompile(`(src|href)=["']media:([^"']+)["']`)

func HTMLBlock(ctx context.Context, content map[string]any) string {
	var htmlTemplate string
	if htmlContent, ok := content["_html_content"].(string); ok && htmlContent != "" {
		htmlTemplate = htmlContent
	} else {
		htmlTemplate, _ = content["html"].(string)
	}

	if htmlTemplate == "" {
		return ""
	}

	enrichedContent := enrichMediaFields(ctx, content)

	result, err := blocks.RenderTemplate(htmlTemplate, enrichedContent)
	if err != nil {
		if blocks.IsEditor(ctx) {
			return fmt.Sprintf(`<div class="bg-red-50 border border-red-200 text-red-700 p-4 rounded">
				<strong>Template Error:</strong> %s
			</div>`, html.EscapeString(err.Error()))
		}
		return ""
	}

	result = blocks.ProcessIcons(result)
	result = ResolveMediaURLs(result)

	return result
}

func enrichMediaFields(ctx context.Context, content map[string]any) map[string]any {
	mediaFields := GetMediaFields(content)
	if len(mediaFields) == 0 {
		return content
	}

	resolver := blocks.GetMediaResolver(ctx)

	enriched := make(map[string]any, len(content))
	maps.Copy(enriched, content)

	for fieldName := range mediaFields {
		value, ok := content[fieldName].(string)
		if !ok || value == "" {
			continue
		}

		mediaValue := parseMediaValue(ctx, resolver, value)
		if mediaValue != nil {
			enriched[fieldName] = mediaValue
		}
	}

	return enriched
}

func parseMediaValue(ctx context.Context, resolver blocks.MediaResolver, value string) *blocks.MediaValue {
	if value == "" {
		return nil
	}

	path := value
	if after, ok := strings.CutPrefix(value, "media:"); ok {
		path = after
	}

	src := path
	if !strings.HasPrefix(path, "/media/") {
		src = "/media/" + path
	}

	parts := strings.SplitN(path, "/", 2)
	if len(parts) == 0 || parts[0] == "" {
		return &blocks.MediaValue{Src: src}
	}

	mediaID, err := uuid.Parse(parts[0])
	if err != nil {
		return &blocks.MediaValue{Src: src}
	}

	if resolver == nil {
		return &blocks.MediaValue{Src: src}
	}

	resolved := resolver.ResolveMedia(ctx, mediaID)
	if resolved == nil {
		return &blocks.MediaValue{Src: src}
	}

	resolved.Src = src
	return resolved
}

// GetMediaFields extracts field names that have x-editor: "media" from customSchema.
func GetMediaFields(content map[string]any) map[string]bool {
	result := make(map[string]bool)

	customSchema, ok := content["customSchema"].(map[string]any)
	if !ok {
		return result
	}

	properties, ok := customSchema["properties"].(map[string]any)
	if !ok {
		return result
	}

	for key, prop := range properties {
		propMap, ok := prop.(map[string]any)
		if !ok {
			continue
		}
		if editor, ok := propMap["x-editor"].(string); ok && editor == "media" {
			result[key] = true
		}
	}

	return result
}

// ResolveMediaURLs converts media: prefixed URLs to proper /media/ paths.
func ResolveMediaURLs(htmlStr string) string {
	return mediaURLRegex.ReplaceAllStringFunc(htmlStr, func(match string) string {
		submatches := mediaURLRegex.FindStringSubmatch(match)
		if len(submatches) < 3 {
			return match
		}
		attr := submatches[1]
		path := submatches[2]

		if strings.HasPrefix(path, "/media/") {
			return fmt.Sprintf(`%s="%s"`, attr, path)
		}
		return fmt.Sprintf(`%s="/media/%s"`, attr, path)
	})
}

var (
	boldRegex   = regexp.MustCompile(`\*\*(.+?)\*\*`)
	italicRegex = regexp.MustCompile(`\*([^*]+?)\*`)
	colorRegex  = regexp.MustCompile(`==(?:([a-z-]+):)?(.+?)==`)
	linkRegex   = regexp.MustCompile(`\[([^\]]+)\]\(([^)]+)\)`)
)

var validThemeColors = map[string]bool{
	"foreground": true, "background": true,
	"primary": true, "primary-foreground": true,
	"secondary": true, "secondary-foreground": true,
	"muted": true, "muted-foreground": true,
	"accent": true, "accent-foreground": true,
	"destructive": true, "destructive-foreground": true,
	"border": true, "card": true, "card-foreground": true,
}

// ProcessMarkdown converts markdown-like syntax to HTML.
func ProcessMarkdown(text string) string {
	text = boldRegex.ReplaceAllString(text, `<strong>$1</strong>`)
	text = italicRegex.ReplaceAllString(text, `<em>$1</em>`)
	text = colorRegex.ReplaceAllStringFunc(text, func(match string) string {
		submatches := colorRegex.FindStringSubmatch(match)
		if len(submatches) < 3 {
			return match
		}
		colorName := submatches[1]
		content := submatches[2]

		if colorName == "" || !validThemeColors[colorName] {
			colorName = "accent"
		}

		return fmt.Sprintf(`<span class="text-%s">%s</span>`, colorName, content)
	})
	text = linkRegex.ReplaceAllStringFunc(text, func(match string) string {
		submatches := linkRegex.FindStringSubmatch(match)
		if len(submatches) < 3 {
			return match
		}
		linkText := submatches[1]
		url := submatches[2]
		url = strings.ReplaceAll(url, "&amp;", "&")
		url = strings.ReplaceAll(url, "&#34;", "\"")
		url = strings.ReplaceAll(url, "&#39;", "'")
		return fmt.Sprintf(`<a href="%s">%s</a>`, html.EscapeString(url), linkText)
	})
	return text
}

// WrapLinesInParagraphs converts textarea newlines to <br> tags.
func WrapLinesInParagraphs(text string) string {
	return strings.ReplaceAll(text, "\n", "<br>")
}

// GetTextareaFields extracts field names that have x-editor: textarea from customSchema.
func GetTextareaFields(content map[string]any) map[string]bool {
	result := make(map[string]bool)

	customSchema, ok := content["customSchema"].(map[string]any)
	if !ok {
		return result
	}

	properties, ok := customSchema["properties"].(map[string]any)
	if !ok {
		return result
	}

	for key, prop := range properties {
		propMap, ok := prop.(map[string]any)
		if !ok {
			continue
		}
		if editor, ok := propMap["x-editor"].(string); ok && editor == "textarea" {
			result[key] = true
		}
	}

	return result
}

// GetArrayItemTextareaFields extracts textarea field names from an array's item schema.
func GetArrayItemTextareaFields(content map[string]any, collectionName string) map[string]bool {
	result := make(map[string]bool)

	customSchema, ok := content["customSchema"].(map[string]any)
	if !ok {
		return result
	}

	properties, ok := customSchema["properties"].(map[string]any)
	if !ok {
		return result
	}

	arrayField, ok := properties[collectionName].(map[string]any)
	if !ok {
		return result
	}

	if itemProperties, ok := arrayField["itemProperties"].(map[string]any); ok {
		for _, prop := range itemProperties {
			propMap, ok := prop.(map[string]any)
			if !ok {
				continue
			}
			if editor, ok := propMap["x-editor"].(string); ok && editor == "textarea" {
				if title, ok := propMap["title"].(string); ok && title != "" {
					result[title] = true
				}
			}
		}
		return result
	}

	items, ok := arrayField["items"].(map[string]any)
	if !ok {
		return result
	}

	itemProps, ok := items["properties"].(map[string]any)
	if !ok {
		return result
	}

	for key, prop := range itemProps {
		propMap, ok := prop.(map[string]any)
		if !ok {
			continue
		}
		if editor, ok := propMap["x-editor"].(string); ok && editor == "textarea" {
			result[key] = true
		}
	}

	return result
}