package main

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

var wikiArticleClient = &http.Client{Timeout: 60 * time.Second}

// wikiPerson carries a person extracted from a wiki article.
type wikiPerson struct {
	Name       string
	Profession int // 1=actor, 2=director, 3=screenwriter
}

// wikiArticleEntry holds extracted fields from a wiki article API response.
type wikiArticleEntry struct {
	Description  string
	Year         int
	PosterURL    string
	Synopsis     string
	License      string
	LicenseURL   string
	NumAccolades int
	People       []wikiPerson
}

func (a *App) queryWikiArticle(name string) (wikiArticleEntry, int, error) {
	// Build URL — name is decoded from DB, encode it for the request
	reqURL := fmt.Sprintf("%s?username=%s&name=%s",
		a.Config.WikiServer, url.QueryEscape(a.Config.WikiUsername), url.PathEscape(name))

	var resp *http.Response
	var err error
	start := time.Now()
	for attempt := 0; attempt < 5; attempt++ {
		if attempt > 0 {
			backoff := 1 << attempt
			logHTTPRetry(attempt, 4, backoff, name)
			time.Sleep(time.Duration(backoff) * time.Second)
		}

		resp, err = wikiArticleClient.Get(reqURL)
		if err != nil {
			continue
		}

		if resp.StatusCode == http.StatusTooManyRequests {
			resp.Body.Close()
			continue
		}

		if resp.StatusCode != http.StatusOK {
			body, _ := io.ReadAll(io.LimitReader(resp.Body, 2048))
			resp.Body.Close()
			logHTTPRequest("GET", reqURL, resp.StatusCode, time.Since(start).Seconds())
			return wikiArticleEntry{}, resp.StatusCode, fmt.Errorf("HTTP %d: %s", resp.StatusCode, body)
		}

		break
	}
	if err != nil {
		logHTTPRequest("GET", reqURL, 0, time.Since(start).Seconds())
		return wikiArticleEntry{}, 0, fmt.Errorf("http get: %w", err)
	}
	defer resp.Body.Close()
	logHTTPRequest("GET", reqURL, resp.StatusCode, time.Since(start).Seconds())

	var articles []map[string]interface{}
	if err := json.NewDecoder(resp.Body).Decode(&articles); err != nil {
		return wikiArticleEntry{}, 200, fmt.Errorf("json decode: %w", err)
	}
	if len(articles) == 0 {
		return wikiArticleEntry{}, 200, fmt.Errorf("no articles returned")
	}
	article := articles[0]

	var entry wikiArticleEntry

	// description
	if desc, ok := article["description"]; ok {
		entry.Description = fmt.Sprintf("%v", desc)
	}

	// synopsis from Plot section
	entry.Synopsis = extractSynopsis(article)

	// year, poster_url from infobox
	entry.Year, entry.PosterURL = extractInfoboxData(article)

	// people from infobox and sections
	entry.People = extractPeople(article)

	// license
	if licList, ok := article["license"]; ok {
		if arr, ok := licList.([]interface{}); ok && len(arr) > 0 {
			if lic, ok := arr[0].(map[string]interface{}); ok {
				entry.License = fmt.Sprintf("%v", lic["name"])
				entry.LicenseURL = fmt.Sprintf("%v", lic["url"])
			}
		}
	}

	// num_accolades from tables
	entry.NumAccolades = extractAccolades(article)

	return entry, 200, nil
}

func extractSynopsis(article map[string]interface{}) string {
	sections, ok := article["sections"].([]interface{})
	if !ok {
		return ""
	}
	for _, sec := range sections {
		s, ok := sec.(map[string]interface{})
		if !ok || s["name"] != "Plot" {
			continue
		}
		var parts []string
		if pp, ok := s["has_parts"].([]interface{}); ok {
			for _, p := range pp {
				if pp2, ok := p.(map[string]interface{}); ok && pp2["type"] == "paragraph" {
					parts = append(parts, fmt.Sprintf("%v", pp2["value"]))
				}
			}
		}
		if len(parts) > 0 {
			return strings.Join(parts, " ")
		}
		return ""
	}
	return ""
}

func extractInfoboxData(article map[string]interface{}) (year int, posterURL string) {
	infoboxes, ok := article["infoboxes"].([]interface{})
	if !ok || len(infoboxes) == 0 {
		return
	}
	ib, ok := infoboxes[0].(map[string]interface{})
	if !ok {
		return
	}
	parts, ok := ib["has_parts"].([]interface{})
	if !ok || len(parts) == 0 {
		return
	}
	section, ok := parts[0].(map[string]interface{})
	if !ok {
		return
	}
	subParts, _ := section["has_parts"].([]interface{})

	for _, p := range subParts {
		fp, ok := p.(map[string]interface{})
		if !ok {
			continue
		}
		// poster from first image
		if fp["type"] == "image" && posterURL == "" {
			if imgs, ok := fp["images"].([]interface{}); ok && len(imgs) > 0 {
				if img, ok := imgs[0].(map[string]interface{}); ok {
					if cu, ok := img["content_url"]; ok {
						posterURL = fmt.Sprintf("%v", cu)
					}
				}
			}
		}
		// year from Release dates
		if fp["name"] == "Release dates" && year == 0 {
			if items, ok := fp["has_parts"].([]interface{}); ok && len(items) > 0 {
				if item, ok := items[0].(map[string]interface{}); ok {
					val := fmt.Sprintf("%v", item["value"])
					year = extractYear(val)
				}
			}
		}
	}
	return
}

func extractYear(s string) int {
	// Look for 4-digit year pattern like "1972" or "(1972-03-14)"
	for i := 0; i+3 < len(s); i++ {
		if s[i] == '(' {
			i++ // skip paren
		}
		if i+4 <= len(s) && s[i] >= '1' && s[i] <= '2' {
			if y, err := strconv.Atoi(s[i : i+4]); err == nil && y >= 1800 && y <= 2100 {
				return y
			}
		}
	}
	return 0
}

func extractAccolades(article map[string]interface{}) int {
	tables, ok := article["tables"].([]interface{})
	if !ok {
		return 0
	}
	total := 0
	for _, t := range tables {
		tab, ok := t.(map[string]interface{})
		if !ok {
			continue
		}
		rows, _ := tab["rows"].([]interface{})
		total += len(rows)
	}
	return total
}

// extractPeople extracts actors, directors, and screenwriters from the article.
func extractPeople(article map[string]interface{}) []wikiPerson {
	var people []wikiPerson

	// Directors and screenwriters from infobox
	ibParts := getInfoboxParts(article)
	for _, p := range ibParts {
		fp, ok := p.(map[string]interface{})
		if !ok {
			continue
		}
		name := fp["name"]
		if name == "Directed by" {
			people = append(people, extractPersonFromField(fp, 2)...)
		}
		if name == "Screenplay by" {
			people = append(people, extractPersonFromField(fp, 3)...)
		}
	}
	// Actors from Cast section
	for _, sec := range getSections(article) {
		s, ok := sec.(map[string]interface{})
		if !ok || s["name"] != "Cast" {
			continue
		}
		if hp, ok := s["has_parts"].([]interface{}); ok {
			for _, part := range hp {
				p, ok := part.(map[string]interface{})
				if !ok || p["type"] != "list" {
					continue
				}
				if items, ok := p["has_parts"].([]interface{}); ok {
					for _, item := range items {
						item, ok := item.(map[string]interface{})
						if !ok {
							continue
						}
						if link, ok := getFirstPersonLink(item); ok {
							people = append(people, wikiPerson{Name: link, Profession: 1})
						}
					}
				}
				break // only first list in Cast section
			}
		}
		break // only Cast section
	}
	return people
}

// getInfoboxParts returns the inner parts of the infobox section.
func getInfoboxParts(article map[string]interface{}) []interface{} {
	infoboxes, ok := article["infoboxes"].([]interface{})
	if !ok || len(infoboxes) == 0 {
		return nil
	}
	ib, ok := infoboxes[0].(map[string]interface{})
	if !ok {
		return nil
	}
	parts, ok := ib["has_parts"].([]interface{})
	if !ok || len(parts) == 0 {
		return nil
	}
	section, ok := parts[0].(map[string]interface{})
	if !ok {
		return nil
	}
	if hp, ok := section["has_parts"].([]interface{}); ok {
		return hp
	}
	return nil
}

// getSections returns sections from the article.
func getSections(article map[string]interface{}) []interface{} {
	sections, ok := article["sections"].([]interface{})
	if !ok {
		return nil
	}
	return sections
}

// extractPersonFromField extracts a person name from a field or list.
func extractPersonFromField(fp map[string]interface{}, profession int) []wikiPerson {
	var people []wikiPerson
	switch fp["type"] {
	case "field":
		if val, ok := fp["value"]; ok && val != nil {
			name := fmt.Sprintf("%v", val)
			if name != "" {
				people = append(people, wikiPerson{Name: name, Profession: profession})
			}
		}
	case "list":
		for _, item := range fp["has_parts"].([]interface{}) {
			item, ok := item.(map[string]interface{})
			if !ok {
				continue
			}
			// Prefer link text over value
			if link, ok := getFirstPersonLink(item); ok {
				people = append(people, wikiPerson{Name: link, Profession: profession})
			} else if val := item["value"]; val != nil {
				name := fmt.Sprintf("%v", val)
				if name != "" {
					people = append(people, wikiPerson{Name: name, Profession: profession})
				}
			}
		}
	}
	return people
}

// getFirstPersonLink extracts the first link text from a list item.
func getFirstPersonLink(item map[string]interface{}) (string, bool) {
	links, ok := item["links"].([]interface{})
	if !ok || len(links) == 0 {
		return "", false
	}
	link, ok := links[0].(map[string]interface{})
	if !ok {
		return "", false
	}
	if text, ok := link["text"]; ok && text != nil {
		s := fmt.Sprintf("%v", text)
		if s != "" {
			return s, true
		}
	}
	return "", false
}