package main

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"os"
	"time"

	"golang.org/x/time/rate"
)

func main() {
	slog.SetDefault(slog.New(slog.NewTextHandler(os.Stderr, nil)))
	if err := run(os.Args, os.Getenv); err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}
}

// envLookup retrieves an environment variable.
type envLookup func(string) string

// run dispatches to the appropriate subcommand.
// It is extracted from main to allow testing of the dispatch and validation logic.
func run(args []string, lookupEnv envLookup) error {
	if len(args) < 2 {
		return errors.New("Usage: popback <viewed|backfill> [args...]")
	}

	switch args[1] {
	case "viewed":
		apiKey := lookupEnv("TMDB_API_KEY")
		if apiKey == "" {
			return errors.New("TMDB_API_KEY required")
		}
		output := "watchlist.csv"
		if len(args) > 2 {
			output = args[2]
		}
		tmdb := newTMDBClient(apiKey)
		store := newCSVStorer()
		return runViewed(context.Background(), tmdb, store, realTUIRunner{}, output)

	case "backfill":
		apiKey := lookupEnv("TMDB_API_KEY")
		if apiKey == "" {
			return errors.New("TMDB_API_KEY required")
		}
		authToken := lookupEnv("POPFEED_AUTH_TOKEN")
		if authToken == "" {
			return errors.New("POPFEED_AUTH_TOKEN required")
		}
		csvPath := "watchlist.csv"
		if len(args) > 2 {
			csvPath = args[2]
		}
		tmdb := newTMDBClient(apiKey)
		store := newCSVStorer()
		pf := newPopfeedClient(authToken)
		tmdb.http = WithRateLimit(tmdb.http, rate.NewLimiter(rate.Every(250*time.Millisecond), 1))
		pf.http = WithRateLimit(pf.http, rate.NewLimiter(rate.Every(50*time.Millisecond), 1))
		return runBackfill(store, tmdb, pf, csvPath)

	default:
		return fmt.Errorf("Unknown command: %s\nUsage: popback <viewed|backfill> [args...]", args[1])
	}
}