package spm

import (
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
	"strings"
)

// Addon struct capturing fields from AMO search results (v5)
type Addon struct {
	ID   int               `json:"id"`
	Name map[string]string `json:"name"`
	Slug string            `json:"slug"`
	URL  string            `json:"url"`

	CurrentVersion struct {
		Version      string            `json:"version"`
		ReleaseNotes map[string]string `json:"release_notes"`
		Files        []struct {
			URL string `json:"url"`
		} `json:"files"`
	} `json:"current_version"`

	Author struct {
		Name string `json:"name"`
	} `json:"author"`

	IconURL string            `json:"icon_url"`
	Summary map[string]string `json:"summary"`
	Tags    []string          `json:"tags"`
	License struct {
		Name string `json:"name"`
	} `json:"license"`

	// Make sure we match the real AMO JSON: "image_url" is where
	// the full-size preview is stored (not "url")
	Previews []struct {
		ID           int    `json:"id"`
		Caption      string `json:"caption"`
		ImageURL     string `json:"image_url"`
		ThumbnailURL string `json:"thumbnail_url"`
	} `json:"previews"`

	ThemeData struct {
		Images struct {
			Header string `json:"header"`
		} `json:"images"`
	} `json:"theme_data"`
}

// AMOResponse is the structure returned by the AMO search endpoint (v5).
type AMOResponse struct {
	Count   int     `json:"count"`
	Results []Addon `json:"results"`
}

func searchMozillaAddons(query, addonType string) ([]AppIndexEntry, error) {
	baseURL := "https://addons.mozilla.org/api/v5/addons/search/"
	q := url.QueryEscape(query)
	apiURL := fmt.Sprintf("%s?app=firefox&q=%s", baseURL, q)
	if addonType != "" && addonType != "all" {
		apiURL += "&type=" + url.QueryEscape(addonType)
	}

	log.Printf("AMO API request: %s", apiURL)
	req, err := http.NewRequest("GET", apiURL, nil)
	if err != nil {
		return nil, fmt.Errorf("failed building request: %w", err)
	}
	req.Header.Set("User-Agent", "MyCustomBrowser/1.0")

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to query AMO: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("AMO returned status: %d", resp.StatusCode)
	}

	bodyBytes, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed reading AMO response: %w", err)
	}

	var amoResp AMOResponse
	if err := json.Unmarshal(bodyBytes, &amoResp); err != nil {
		return nil, fmt.Errorf("failed parsing AMO JSON: %w", err)
	}

	var entries []AppIndexEntry
	for _, a := range amoResp.Results {
		// Determine display name.
		var addonName string
		if val, ok := a.Name["en-US"]; ok && val != "" {
			addonName = val
		} else {
			for _, v := range a.Name {
				addonName = v
				break
			}
			if addonName == "" {
				addonName = "Unknown Add-on"
			}
		}

		finalType := addonType
		if finalType == "" || finalType == "all" {
			finalType = "addon"
		}

		// Pick download URL from current version if present.
		downloadURL := a.URL
		if len(a.CurrentVersion.Files) > 0 && a.CurrentVersion.Files[0].URL != "" {
			downloadURL = a.CurrentVersion.Files[0].URL
		}

		// Gather screenshot URLs from Previews using preview.ImageURL.
		var screenshots []string
		for _, preview := range a.Previews {
			screenshots = append(screenshots, preview.ImageURL)
		}

		// If this is a theme, override screenshots to first preview.
		if strings.EqualFold(finalType, "theme") || strings.EqualFold(finalType, "statictheme") ||
			strings.EqualFold(addonType, "theme") || strings.EqualFold(addonType, "statictheme") {
			if len(a.Previews) > 0 {
				log.Printf("Using first preview for theme %s: %s", a.Slug, a.Previews[0].ImageURL)
				screenshots = []string{a.Previews[0].ImageURL}
			} else {
				log.Printf("No preview images available for theme %s", a.Slug)
			}
		}

		// Release notes
		releaseNotes := ""
		if rn, ok := a.CurrentVersion.ReleaseNotes["en-US"]; ok && rn != "" {
			releaseNotes = rn
		} else {
			for _, rn := range a.CurrentVersion.ReleaseNotes {
				releaseNotes = rn
				break
			}
		}

		// Description
		description := ""
		if d, ok := a.Summary["en-US"]; ok && d != "" {
			description = d
		} else {
			for _, d := range a.Summary {
				description = d
				break
			}
		}

		entries = append(entries, AppIndexEntry{
			Name:        addonName,
			Version:     a.CurrentVersion.Version,
			Type:        finalType,
			DownloadURL: downloadURL,
			Maintainer:  a.Author.Name,
			Icon:        a.IconURL,
			Screenshots: screenshots,
			Tags:        a.Tags,
			Description: description,
			URL:         a.URL,
			License:     a.License.Name,
			Notes:       releaseNotes,
		})
	}

	log.Printf("AMO results: %d", len(entries))
	return entries, nil
}

// Search in local SPM index by type
func searchLocalByType(typeFilter string) ([]AppIndexEntry, error) {
	allEntries, err := GetIndex()
	if err != nil {
		return nil, err
	}
	var filtered []AppIndexEntry
	for _, e := range allEntries {
		if strings.EqualFold(e.Type, typeFilter) {
			filtered = append(filtered, e)
		}
	}
	return filtered, nil
}

// Search in local SPM index for all, optionally filtered by name substring.
func searchLocalAll(query string) ([]AppIndexEntry, error) {
	allEntries, err := GetIndex()
	if err != nil {
		return nil, err
	}
	if query == "" {
		return allEntries, nil
	}
	var result []AppIndexEntry
	for _, e := range allEntries {
		if strings.Contains(strings.ToLower(e.Name), strings.ToLower(query)) {
			result = append(result, e)
		}
	}
	return result, nil
}

// SearchPackages coordinates between local and AMO-based searches depending on filter
func SearchPackages(query, filter string) ([]AppIndexEntry, error) {
	switch filter {
	case "addon":
		return searchMozillaAddons(query, "extension")
	case "theme":
		return searchMozillaAddons(query, "statictheme")
	case "layout", "bundle", "config":
		return searchLocalByType(filter)
	case "", "all":
		localAll, err := searchLocalAll(query)
		if err != nil {
			return nil, fmt.Errorf("local search error: %w", err)
		}
		mozExt, err := searchMozillaAddons(query, "extension")
		if err != nil {
			return nil, fmt.Errorf("mozilla (extension) error: %w", err)
		}
		mozTheme, err := searchMozillaAddons(query, "statictheme")
		if err != nil {
			return nil, fmt.Errorf("mozilla (theme) error: %w", err)
		}
		return append(append(localAll, mozExt...), mozTheme...), nil
	default:
		return nil, fmt.Errorf("unrecognized filter: %s", filter)
	}
}