package config

import (
	_ "embed"
	"fmt"
	"os"
	"regexp"
	"strings"
	"time"

	"github.com/rs/zerolog/log"
	"gopkg.in/yaml.v3"
)

//go:embed config.yaml
var defaultConfig []byte

func Init(configPath string) error {
	if _, err := os.Lstat(configPath); err == nil {
		return fmt.Errorf("config exists at %q", configPath)
	}

	fi, err := os.Create(configPath)
	if err != nil {
		return err
	}
	defer fi.Close()

	_, err = fi.Write(defaultConfig)
	return err
}

type Config struct {
	Backoff time.Duration `yaml:"backoff"`
	Reddit  RedditConfig  `yaml:"reddit"`
	Twitter TwitterConfig `yaml:"twitter"`
}

func (c *Config) initReddit() {
	for _, sub := range c.Reddit.SubReddits {
		c.Reddit.Map[strings.ToLower(sub.Name)] = sub
		if sub.TitleLimit == 0 || sub.TitleLimit > 253 {
			sub.TitleLimit = 253
		}
		if sub.BodyLimit == 0 || sub.BodyLimit > 2045 {
			sub.BodyLimit = 2045
		}
		sub.FlairAllowlistRe = make([]*regexp.Regexp, len(sub.FlairAllowlist))
		for idx, f := range sub.FlairAllowlist {
			sub.FlairAllowlistRe[idx] = regexp.MustCompile(f)
		}
		sub.FlairBlocklistRe = make([]*regexp.Regexp, len(sub.FlairBlocklist))
		for idx, f := range sub.FlairBlocklist {
			sub.FlairBlocklistRe[idx] = regexp.MustCompile(f)
		}
		sub.TitleAllowlistRe = make([]*regexp.Regexp, len(sub.TitleAllowlist))
		for idx, t := range sub.TitleAllowlist {
			sub.TitleAllowlistRe[idx] = regexp.MustCompile(t)
		}
		sub.TitleBlocklistRe = make([]*regexp.Regexp, len(sub.TitleBlocklist))
		for idx, t := range sub.TitleBlocklist {
			sub.TitleBlocklistRe[idx] = regexp.MustCompile(t)
		}
		sub.BodyAllowlistRe = make([]*regexp.Regexp, len(sub.BodyAllowlist))
		for idx, b := range sub.BodyAllowlist {
			sub.BodyAllowlistRe[idx] = regexp.MustCompile(b)
		}
		sub.BodyBlocklistRe = make([]*regexp.Regexp, len(sub.BodyBlocklist))
		for idx, b := range sub.BodyBlocklist {
			sub.BodyBlocklistRe[idx] = regexp.MustCompile(b)
		}
	}
}

func Load(configPath string) (*Config, error) {
	cfg := Config{
		Reddit: RedditConfig{
			Map: make(map[string]*SubReddit),
		},
	}

	fi, err := os.Open(configPath)
	if err != nil {
		return nil, fmt.Errorf("could not open config: %v", err)
	}

	if err := yaml.NewDecoder(fi).Decode(&cfg); err != nil {
		return nil, fmt.Errorf("could not decode config: %v", err)
	}

	cfg.initReddit()
	log.Debug().Msgf("%#v", cfg)
	return &cfg, nil
}