package main

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

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()

	// Open output CSV file
	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)
	writer.UseCRLF = true
	writer.Comma = ','
	defer writer.Flush()

	processFile(inputFileName, apiKey, writer)

	// Check failed.csv
	checkFailedCsv(apiKey, writer)
}

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

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

	// Open failed.csv
	failedFileName := "failed.csv"
	failedFile, err := os.Create(failedFileName)
	if err != nil {
		fmt.Printf("Error creating failed.csv: %v\n", err)
		return
	}
	defer failedFile.Close()

	failedWriter := csv.NewWriter(failedFile)
	failedWriter.UseCRLF = true
	failedWriter.Comma = ','
	defer failedWriter.Flush()

	scanner := bufio.NewScanner(file)

	requests := time.Tick(time.Millisecond * 20) // Limit requests to 50 per second

	for scanner.Scan() {
		<-requests // Wait until we are allowed to perform a request
		movie := scanner.Text()
		movie = strings.Trim(movie, "\"") // Remove surrounding quotes
		title, year, err := parseMovieTitleYear(movie)
		if err != nil {
			fmt.Printf("Failed to parse movie: %s, Error: %v\n", movie, err)
			_ = failedWriter.Write([]string{title, year})
			failedWriter.Flush() // Immediately write the failed record to the file
			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)
			_ = failedWriter.Write([]string{title, year})
			failedWriter.Flush() // Immediately write the failed record to the file
			continue
		}
		record := []string{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 := parts[1]
	return title, year, nil
}

func getMovieData(title, year, apiKey string) (float64, error) {
	// url encode the title
	encodedTitle := url.QueryEscape(title)

	url := fmt.Sprintf("https://api.themoviedb.org/3/search/movie?include_adult=false&language=en-US&year=%s&page=1&query=%s", year, encodedTitle)

	req, _ := http.NewRequest("GET", url, nil)
	req.Header.Add("Authorization", "Bearer "+apiKey)
	req.Header.Add("accept", "application/json")

	res, err := http.DefaultClient.Do(req)
	if err != nil || res == nil {
		return 0, fmt.Errorf("failed to make request: %v", err)
	}

	if res.StatusCode != 200 {
		return 0, fmt.Errorf("received non-200 response: %d", res.StatusCode)
	}

	defer res.Body.Close()

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

	if len(response.Results) == 0 {
		return 0, fmt.Errorf("no results found")
	}
	return response.Results[0].Popularity, nil
}

func checkFailedCsv(apiKey string, writer *csv.Writer) {
	for {
		fmt.Println("Do you want to check failed.csv and retry fetching data for failed movies? (Y/n)")
		retry := getInput()
		if strings.EqualFold(retry, "n") {
			break
		}
		if retry == "" || strings.EqualFold(retry, "y") {
			fmt.Println("Processing failed.csv...")
			// Recreate failed.csv for the next run
			failedFileName := "failed.csv"
			failedFile, err := os.Create(failedFileName)
			if err != nil {
				fmt.Printf("Error creating failed.csv: %v\n", err)
				return
			}
			failedFile.Close()

			// Process the old failed.csv
			processFile(failedFileName, apiKey, writer)
		}
	}
}