// Copyright 2026 MarketAlly. All rights reserved.
// SPDX-License-Identifier: MIT

package pages

import (
	"context"
	"errors"
	"fmt"
	"strconv"
	"strings"

	repo_model "code.gitcaddy.com/server/v3/models/repo"
	"code.gitcaddy.com/server/v3/modules/ai"
	"code.gitcaddy.com/server/v3/modules/json"
	pages_module "code.gitcaddy.com/server/v3/modules/pages"
)

// aiGeneratedConfig holds the AI-generated landing page content
type aiGeneratedConfig struct {
	Brand struct {
		Name    string `json:"name"`
		Tagline string `json:"tagline"`
	} `json:"brand"`
	Hero struct {
		Headline    string `json:"headline"`
		Subheadline string `json:"subheadline"`
		PrimaryCTA  struct {
			Label string `json:"label"`
			URL   string `json:"url"`
		} `json:"primary_cta"`
		SecondaryCTA struct {
			Label string `json:"label"`
			URL   string `json:"url"`
		} `json:"secondary_cta"`
	} `json:"hero"`
	Stats      []pages_module.StatConfig      `json:"stats"`
	ValueProps []pages_module.ValuePropConfig `json:"value_props"`
	Features   []pages_module.FeatureConfig   `json:"features"`
	CTASection struct {
		Headline    string `json:"headline"`
		Subheadline string `json:"subheadline"`
		ButtonLabel string `json:"button_label"`
		ButtonURL   string `json:"button_url"`
	} `json:"cta_section"`
	SEO struct {
		Title       string `json:"title"`
		Description string `json:"description"`
	} `json:"seo"`
}

// GenerateLandingPageContent uses AI to auto-generate landing page content from repo metadata.
func GenerateLandingPageContent(ctx context.Context, repo *repo_model.Repository, readme string) (*pages_module.LandingConfig, error) {
	if !ai.IsEnabled() {
		return nil, errors.New("AI service is not enabled")
	}

	repoURL := repo.HTMLURL()
	topics := strings.Join(repo.Topics, ", ")

	client := ai.GetClient()
	resp, err := client.ExecuteTask(ctx, &ai.ExecuteTaskRequest{
		RepoID: repo.ID,
		Task:   "landing_page_generate",
		Context: map[string]string{
			"repo_name":        repo.Name,
			"repo_description": repo.Description,
			"repo_url":         repoURL,
			"topics":           topics,
			"primary_language": getPrimaryLanguageName(repo),
			"stars":            strconv.Itoa(repo.NumStars),
			"forks":            strconv.Itoa(repo.NumForks),
			"readme":           truncateReadme(readme),
		},
	})
	if err != nil {
		return nil, fmt.Errorf("AI generation failed: %w", err)
	}

	if !resp.Success {
		return nil, fmt.Errorf("AI generation error: %s", resp.Error)
	}

	var generated aiGeneratedConfig
	if err := json.Unmarshal([]byte(extractJSON(resp.Result)), &generated); err != nil {
		return nil, fmt.Errorf("failed to parse AI response: %w", err)
	}

	// Build LandingConfig from AI response
	config := pages_module.DefaultConfig()
	config.Brand.Name = generated.Brand.Name
	config.Brand.Tagline = generated.Brand.Tagline
	config.Hero.Headline = generated.Hero.Headline
	config.Hero.Subheadline = generated.Hero.Subheadline
	config.Hero.PrimaryCTA = pages_module.CTAButton{
		Label: generated.Hero.PrimaryCTA.Label,
		URL:   repoURL,
	}
	config.Hero.SecondaryCTA = pages_module.CTAButton{
		Label: generated.Hero.SecondaryCTA.Label,
		URL:   repoURL,
	}
	if len(generated.Stats) > 0 {
		config.Stats = generated.Stats
	}
	if len(generated.ValueProps) > 0 {
		config.ValueProps = generated.ValueProps
	}
	if len(generated.Features) > 0 {
		config.Features = generated.Features
	}
	config.CTASection = pages_module.CTASectionConfig{
		Headline:    generated.CTASection.Headline,
		Subheadline: generated.CTASection.Subheadline,
		Button: pages_module.CTAButton{
			Label: generated.CTASection.ButtonLabel,
			URL:   repoURL,
		},
	}
	if generated.SEO.Title != "" {
		config.SEO.Title = generated.SEO.Title
	}
	if generated.SEO.Description != "" {
		config.SEO.Description = generated.SEO.Description
	}

	return config, nil
}

// getPrimaryLanguageName returns the primary language name for the repo, or empty string
func getPrimaryLanguageName(repo *repo_model.Repository) string {
	if repo.PrimaryLanguage != nil {
		return repo.PrimaryLanguage.Language
	}
	return ""
}

// extractJSON extracts JSON from an AI response that may be wrapped in markdown code fences.
func extractJSON(s string) string {
	s = strings.TrimSpace(s)

	// Strip ```json ... ``` or ``` ... ``` wrapper
	if strings.HasPrefix(s, "```") {
		// Remove opening fence (```json or ```)
		if idx := strings.Index(s, "\n"); idx != -1 {
			s = s[idx+1:]
		}
		// Remove closing fence
		if idx := strings.LastIndex(s, "```"); idx != -1 {
			s = s[:idx]
		}
		s = strings.TrimSpace(s)
	}

	// If still not starting with {, try to find first { and last }
	if !strings.HasPrefix(s, "{") {
		start := strings.Index(s, "{")
		end := strings.LastIndex(s, "}")
		if start != -1 && end != -1 && end > start {
			s = s[start : end+1]
		}
	}

	return s
}

// truncateReadme limits README content to avoid sending too much to the AI
func truncateReadme(readme string) string {
	const maxLen = 4000
	if len(readme) <= maxLen {
		return readme
	}
	return readme[:maxLen] + "\n... (truncated)"
}

// TranslateLandingPageContent uses AI to translate landing page content to a target language.
// Returns a JSON overlay string that can be deep-merged onto the base config.
func TranslateLandingPageContent(ctx context.Context, repo *repo_model.Repository, config *pages_module.LandingConfig, targetLang string) (string, error) {
	if !ai.IsEnabled() {
		return "", errors.New("AI service is not enabled")
	}

	langNames := pages_module.LanguageDisplayNames()
	langName := langNames[targetLang]
	if langName == "" {
		langName = targetLang
	}

	// Build the source content to translate
	sourceContent := buildTranslatableContent(config)

	client := ai.GetClient()
	resp, err := client.ExecuteTask(ctx, &ai.ExecuteTaskRequest{
		RepoID: repo.ID,
		Task:   "landing_page_translate",
		Context: map[string]string{
			"target_language": langName,
			"target_code":     targetLang,
			"source_content":  sourceContent,
		},
	})
	if err != nil {
		return "", fmt.Errorf("AI translation failed: %w", err)
	}

	if !resp.Success {
		return "", fmt.Errorf("AI translation error: %s", resp.Error)
	}

	// Validate it's valid JSON
	result := extractJSON(resp.Result)
	var check map[string]any
	if err := json.Unmarshal([]byte(result), &check); err != nil {
		return "", fmt.Errorf("AI returned invalid JSON: %w", err)
	}

	return result, nil
}

// buildTranslatableContent extracts translatable text from a config for the AI
func buildTranslatableContent(config *pages_module.LandingConfig) string {
	content := map[string]any{}

	// Brand
	if config.Brand.Name != "" || config.Brand.Tagline != "" {
		content["brand"] = map[string]any{
			"name":    config.Brand.Name,
			"tagline": config.Brand.Tagline,
		}
	}

	// Hero
	content["hero"] = map[string]any{
		"headline":      config.Hero.Headline,
		"subheadline":   config.Hero.Subheadline,
		"primary_cta":   map[string]string{"label": config.Hero.PrimaryCTA.Label},
		"secondary_cta": map[string]string{"label": config.Hero.SecondaryCTA.Label},
	}

	// Stats, Value Props, Features (already struct-serializable)
	if len(config.Stats) > 0 {
		content["stats"] = config.Stats
	}
	if len(config.ValueProps) > 0 {
		content["value_props"] = config.ValueProps
	}
	if len(config.Features) > 0 {
		content["features"] = config.Features
	}

	// Testimonials
	if len(config.SocialProof.Testimonials) > 0 {
		testimonials := make([]map[string]string, 0, len(config.SocialProof.Testimonials))
		for _, t := range config.SocialProof.Testimonials {
			testimonials = append(testimonials, map[string]string{
				"quote": t.Quote,
				"role":  t.Role,
			})
		}
		content["social_proof"] = map[string]any{"testimonials": testimonials}
	}

	// Pricing
	if config.Pricing.Headline != "" || len(config.Pricing.Plans) > 0 {
		pricing := map[string]any{
			"headline":    config.Pricing.Headline,
			"subheadline": config.Pricing.Subheadline,
		}
		if len(config.Pricing.Plans) > 0 {
			plans := make([]map[string]string, 0, len(config.Pricing.Plans))
			for _, p := range config.Pricing.Plans {
				plans = append(plans, map[string]string{
					"name":   p.Name,
					"period": p.Period,
					"cta":    p.CTA,
				})
			}
			pricing["plans"] = plans
		}
		content["pricing"] = pricing
	}

	// CTA Section
	content["cta_section"] = map[string]any{
		"headline":    config.CTASection.Headline,
		"subheadline": config.CTASection.Subheadline,
		"button":      map[string]string{"label": config.CTASection.Button.Label},
	}

	// Blog
	if config.Blog.Enabled {
		blogHeadline := config.Blog.Headline
		if blogHeadline == "" {
			blogHeadline = "Latest Posts"
		}
		blog := map[string]any{
			"headline":    blogHeadline,
			"subheadline": config.Blog.Subheadline,
		}
		if config.Blog.CTAButton.Label != "" {
			blog["cta_button"] = map[string]string{"label": config.Blog.CTAButton.Label}
		}
		content["blog"] = blog
	}

	// Gallery
	if config.Gallery.Enabled {
		galleryHeadline := config.Gallery.Headline
		if galleryHeadline == "" {
			galleryHeadline = "Gallery"
		}
		content["gallery"] = map[string]any{
			"headline":    galleryHeadline,
			"subheadline": config.Gallery.Subheadline,
		}
	}

	// Comparison
	if config.Comparison.Enabled {
		compHeadline := config.Comparison.Headline
		if compHeadline == "" {
			compHeadline = "How We Compare"
		}
		content["comparison"] = map[string]any{
			"headline":    compHeadline,
			"subheadline": config.Comparison.Subheadline,
		}
	}

	// Footer
	if config.Footer.Copyright != "" || len(config.Footer.Links) > 0 {
		footer := map[string]any{
			"copyright": config.Footer.Copyright,
		}
		if len(config.Footer.Links) > 0 {
			links := make([]map[string]string, 0, len(config.Footer.Links))
			for _, l := range config.Footer.Links {
				links = append(links, map[string]string{"label": l.Label})
			}
			footer["links"] = links
		}
		content["footer"] = footer
	}

	// SEO
	if config.SEO.Title != "" || config.SEO.Description != "" {
		content["seo"] = map[string]any{
			"title":       config.SEO.Title,
			"description": config.SEO.Description,
		}
	}

	// Navigation labels (for translating nav items and section headers)
	// Use template-specific defaults so AI translates the correct terms
	// (e.g. "Systems Analysis" for architecture-deep-dive, not generic "Value Props")
	defaults := pages_module.TemplateDefaultLabels(config.Template)
	labelOrDefault := func(label, def string) string {
		if label != "" {
			return label
		}
		return def
	}
	content["navigation"] = map[string]any{
		"label_value_props": labelOrDefault(config.Navigation.LabelValueProps, defaults.LabelValueProps),
		"label_features":    labelOrDefault(config.Navigation.LabelFeatures, defaults.LabelFeatures),
		"label_pricing":     labelOrDefault(config.Navigation.LabelPricing, defaults.LabelPricing),
		"label_blog":        labelOrDefault(config.Navigation.LabelBlog, defaults.LabelBlog),
		"label_gallery":     labelOrDefault(config.Navigation.LabelGallery, defaults.LabelGallery),
		"label_compare":     labelOrDefault(config.Navigation.LabelCompare, defaults.LabelCompare),
		"label_docs":        labelOrDefault(config.Navigation.LabelDocs, "Docs"),
		"label_releases":    labelOrDefault(config.Navigation.LabelReleases, "Releases"),
		"label_api":         labelOrDefault(config.Navigation.LabelAPI, "API"),
		"label_issues":      labelOrDefault(config.Navigation.LabelIssues, "Issues"),
	}

	data, _ := json.Marshal(content)
	return string(data)
}