package github

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/url"
	"strings"

	"gitea.weiker.me/rodin/review-bot/vcs"
)

// GetFileContent fetches a file from the default branch of a repo.
// Delegates to GetFileContentAtRef with an empty ref.
func (c *Client) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
	return c.GetFileContentAtRef(ctx, owner, repo, path, ref)
}

// ListContents lists files and directories at a given path in a repo.
// Returns the directory listing from the GitHub contents API.
func (c *Client) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
	reqURL := fmt.Sprintf("%s/repos/%s/%s/contents/%s",
		c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(path))
	body, err := c.doGet(ctx, reqURL)
	if err != nil {
		return nil, fmt.Errorf("list contents %s: %w", path, err)
	}
	var entries []struct {
		Name string `json:"name"`
		Path string `json:"path"`
		Type string `json:"type"`
	}
	if err := json.Unmarshal(body, &entries); err != nil {
		return nil, fmt.Errorf("parse contents JSON: %w", err)
	}
	result := make([]vcs.ContentEntry, len(entries))
	for i, e := range entries {
		result[i] = vcs.ContentEntry{
			Name: e.Name,
			Path: e.Path,
			Type: e.Type,
		}
	}
	return result, nil
}

// escapePath escapes each segment of a relative file path for use in URLs.
// Slashes are preserved as path separators; other special characters are escaped.
func escapePath(p string) string {
	parts := strings.Split(p, "/")
	for i, part := range parts {
		parts[i] = url.PathEscape(part)
	}
	return strings.Join(parts, "/")
}

// decodeBase64Content decodes base64-encoded content from the GitHub contents API.
// GitHub returns base64 content with newlines for formatting, which we strip before decoding.
func decodeBase64Content(encoded string) (string, error) {
	// GitHub inserts newlines in base64 content
	cleaned := strings.ReplaceAll(encoded, "\n", "")
	decoded, err := base64.StdEncoding.DecodeString(cleaned)
	if err != nil {
		return "", err
	}
	return string(decoded), nil
}