// Package config loads yaju-keisatsu's YAML configuration file.
package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v3"
)

type Config struct {
	ListenAddr    string   `yaml:"listen_addr"`
	WebhookSecret string   `yaml:"webhook_secret"`
	Forgejo       Forgejo  `yaml:"forgejo"`
	Bot           Bot      `yaml:"bot"`
	Phrases       []string `yaml:"phrases"`
}

type Forgejo struct {
	BaseURL string `yaml:"base_url"`
	Token   string `yaml:"token"`
}

type Bot struct {
	// Username is the Forgejo account the API token belongs to. Comments
	// authored by this account are ignored so the bot never replies to itself.
	Username string `yaml:"username"`
	// BranchPrefix is prepended to the auto-generated correction branch name.
	BranchPrefix string `yaml:"branch_prefix"`
	// TargetExtensions limits which pushed files are scanned for corrections.
	// An empty list scans every file.
	TargetExtensions []string `yaml:"target_extensions"`
}

func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read config: %w", err)
	}

	cfg := &Config{
		ListenAddr: ":8080",
		Bot: Bot{
			BranchPrefix: "bot/goroku-fix/",
		},
	}
	if err := yaml.Unmarshal(data, cfg); err != nil {
		return nil, fmt.Errorf("parse config: %w", err)
	}

	if cfg.Forgejo.BaseURL == "" {
		return nil, fmt.Errorf("forgejo.base_url is required")
	}
	if cfg.Forgejo.Token == "" {
		return nil, fmt.Errorf("forgejo.token is required")
	}
	if cfg.WebhookSecret == "" {
		return nil, fmt.Errorf("webhook_secret is required")
	}
	if len(cfg.Phrases) == 0 {
		return nil, fmt.Errorf("phrases list is empty")
	}

	return cfg, nil
}