package main

import (
	"bytes"
	"context"
	"errors"
	"flag"
	"fmt"
	"os"
	"time"
)

func cmdSchedule(ctx context.Context, args []string) error {
	fs := flag.NewFlagSet("schedule", flag.ContinueOnError)
	var c commonFlags
	c.register(fs, "json")
	season := fs.Int("season", defaultSeason, "season id; see the crawl or leagues command")
	if err := fs.Parse(args); err != nil {
		return err
	}

	path := SchedulePath(*season)
	page, err := c.read(ctx, c.client(), path, fmt.Sprintf("season %d", *season))
	if errors.Is(err, errUnchanged) {
		return nil
	}
	if err != nil {
		return err
	}
	s, err := ParseSchedule(*season, bytes.NewReader(page))
	if err != nil {
		return err
	}
	var b []byte
	if c.format == "ndjson" {
		b, err = renderNDJSON(s)
	} else {
		b, err = render(c.format, s)
	}
	if err != nil {
		return err
	}
	if err := emit(c.out, c.check, b); err != nil {
		return err
	}
	if c.state != "" {
		if err := saveState(c.state, &state{Path: path, SHA256: sha256Hex(page), LastUpdate: s.LastUpdate, SavedAt: nowStamp()}); err != nil {
			return err
		}
	}
	if !c.quiet {
		fmt.Fprintf(os.Stderr, "season %d: %d games, %d played, last update %s\n",
			s.SeasonID, len(s.Games), s.Played(), s.LastUpdate)
	}
	return nil
}

func cmdLeagues(ctx context.Context, args []string) error {
	fs := flag.NewFlagSet("leagues", flag.ContinueOnError)
	var c commonFlags
	c.register(fs, "json")
	if err := fs.Parse(args); err != nil {
		return err
	}
	page, err := c.read(ctx, c.client(), "/", "front page")
	if errors.Is(err, errUnchanged) {
		return nil
	}
	if err != nil {
		return err
	}
	leagues, err := ParseLeagues(bytes.NewReader(page))
	if err != nil {
		return err
	}
	var b []byte
	if c.format == "csv" {
		var out bytes.Buffer
		out.WriteString("id,name,path\n")
		for _, l := range leagues {
			fmt.Fprintf(&out, "%d,%s,%s\n", l.ID, l.Name, l.Path)
		}
		b = out.Bytes()
	} else {
		var buf bytes.Buffer
		enc := jsonEncoder(&buf)
		if err := enc.Encode(leagues); err != nil {
			return err
		}
		b = buf.Bytes()
	}
	return emit(c.out, c.check, b)
}

// crawlError is what a "record" run emits in place of a season, so a broken
// page is a visible hole in the output rather than a missing line.
type crawlError struct {
	SeasonID int    `json:"season_id"`
	Label    string `json:"label"`
	Error    string `json:"error"`
}

func nowStamp() string { return time.Now().UTC().Format(time.RFC3339) }