// Package config loads and validates the server configuration from the
// environment. All settings are required and validated at startup so the
// process fails fast with a clear message instead of at first request.
package config

import (
	"errors"
	"fmt"
	"net/url"
	"os"
	"strings"
)

// Config holds the validated runtime configuration.
type Config struct {
	// WoodpeckerURL is the base URL of the Woodpecker CI server
	// (e.g. "https://woodpecker.example.com").
	WoodpeckerURL string
	// WoodpeckerToken is the personal access token used for API authentication.
	WoodpeckerToken string
}

// Load reads configuration from the environment and validates it.
func Load() (*Config, error) {
	cfg := &Config{
		WoodpeckerURL:   os.Getenv("WOODPECKER_URL"),
		WoodpeckerToken: os.Getenv("WOODPECKER_TOKEN"),
	}

	if cfg.WoodpeckerURL == "" {
		return nil, errors.New("WOODPECKER_URL is required (e.g. https://woodpecker.example.com)")
	}

	u, err := url.Parse(cfg.WoodpeckerURL)
	if err != nil {
		return nil, fmt.Errorf("WOODPECKER_URL is not a valid URL: %w", err)
	}
	if u.Scheme != "http" && u.Scheme != "https" {
		return nil, fmt.Errorf("WOODPECKER_URL must use http or https scheme, got %q", u.Scheme)
	}
	if u.Host == "" {
		return nil, errors.New("WOODPECKER_URL must include a host (e.g. https://woodpecker.example.com)")
	}

	if cfg.WoodpeckerToken == "" {
		return nil, errors.New("WOODPECKER_TOKEN is required")
	}

	return cfg, nil
}

// APIBaseURL returns the Woodpecker REST API base URL: the server URL with a
// single trailing slash stripped and "/api" appended.
func (c *Config) APIBaseURL() string {
	return strings.TrimSuffix(c.WoodpeckerURL, "/") + "/api"
}