package main

import (
	"bufio"
	"encoding/csv"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"strings"
)

type Movie struct {
	Adult             bool
	Backdrop_path     string
	Genre_ids         []int
	Id                int
	Original_language string
	Original_title    string
	Overview          string
	Popularity        float64
	Poster_path       string
	Release_date      string
	Title             string
	Video             bool
	Vote_average      float64
	Vote_count        int
}

type Response struct {
	Page          int
	Results       []Movie
	Total_pages   int
	Total_results int
}

func main() {
	fmt.Println("Enter the input CSV file name:")
	inputFileName := getInput()
	fmt.Println("Enter the TMDB API Key:")
	apiKey := getInput()

	outputFileName := "movies.csv"
	outputFile, err := os.Create(outputFileName)
	if err != nil {
		fmt.Printf("Error creating output file: %v\n", err)
		return
	}
	defer outputFile.Close()

	writer := csv.NewWriter(outputFile)
	defer writer.Flush()

	processFile(inputFileName, apiKey, writer)

	checkFailedCsv(apiKey, writer)
}

func getInput() string {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	return scanner.Text()
}

func processFile(inputFileName, apiKey string, writer *csv.Writer) {
	file, err := os.Open(inputFileName)
	if err != nil {
		fmt.Printf("Error opening file: %v\n", err)
		return
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		movie := scanner.Text()
		title, year, err := parseMovieTitleYear(movie)
		if err != nil {
			fmt.Printf("Failed to parse movie: %s, Error: %v\n", movie, err)
			continue
		}
		fmt.Printf("Searching for movie: %s\n", movie)
		popularity, err := getMovieData(title, year, apiKey)
		if err != nil {
			fmt.Printf("Failed to get data for movie: %s, Error: %v\n", movie, err)
			continue
		}
		record := []string{fmt.Sprintf("%q", title), year, fmt.Sprintf("%f", popularity)}
		_ = writer.Write(record)
		fmt.Printf("Movie: %s, Popularity: %f\n", movie, popularity)
	}
}

func parseMovieTitleYear(movie string) (string, string, error) {
	parts := strings.SplitN(movie, ",", 2)
	if len(parts) < 2 {
		return "", "", fmt.Errorf("invalid movie format: %s", movie)
	}
	title := parts[0]
	year := strings.TrimSpace(parts[1])
	return title, year, nil
}

func getMovieData(title, year, apiKey string) (float64, error) {
	title = url.QueryEscape(title)
	url := fmt.Sprintf("https://api.themoviedb.org/3/search/movie?api_key=%s&query=%s&year=%s", apiKey, title, year)

	resp, err := http.Get(url)
	if err != nil {
		return 0, fmt.Errorf("failed to send request to TMDB: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		fmt.Printf("Failed request: URL: %s, Status Code: %d, Response: %s\n", url, resp.StatusCode, string(body))
		return 0, fmt.Errorf("failed request with status code: %d", resp.StatusCode)
	}

	var response Response
	err = json.NewDecoder(resp.Body).Decode(&response)
	if err != nil {
		return 0, fmt.Errorf("failed to decode response from TMDB: %w", err)
	}

	if len(response.Results) == 0 {
		fmt.Printf("No results found for: URL: %s\n", url)
		return 0, fmt.Errorf("no results found")
	}

	return response.Results[0].Popularity, nil
}

func checkFailedCsv(apiKey string, writer *csv.Writer) {
	failedFile, err := os.Open("failed.csv")
	if err != nil {
		fmt.Printf("Error opening failed.csv: %v\n", err)
		return
	}
	defer failedFile.Close()

	scanner := bufio.NewScanner(failedFile)
	for scanner.Scan() {
		movie := scanner.Text()
		title, year, err := parseMovieTitleYear(movie)
		if err != nil {
			fmt.Printf("Failed to parse movie from failed.csv: %s, Error: %v\n", movie, err)
			continue
		}
		popularity, err := getMovieData(title, year, apiKey)
		if err == nil {
			record := []string{fmt.Sprintf("%q", title), year, fmt.Sprintf("%f", popularity)}
			_ = writer.Write(record)
			fmt.Printf("Retrieved previously failed movie: %s, Popularity: %f\n", movie, popularity)
		}
	}

	err = os.Remove("failed.csv")
	if err != nil {
		fmt.Printf("Error deleting failed.csv: %v\n", err)
	}
}