package main

import (
	"errors"
	"fmt"
	"net/http"
	"strconv"
	"strings"

	"github.com/jackc/pgx/v5"
	"go.lindenii.runxiyu.org/lindenii-common/clog"
)

type http_router_t struct{}

func (router *http_router_t) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	clog.Info("Incoming HTTP: " + r.RemoteAddr + " " + r.Method + " " + r.RequestURI)

	segments, _, err := parse_request_uri(r.RequestURI)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	non_empty_last_segments_len := len(segments)

	trailing_slash := false

	if segments[len(segments)-1] == "" {
		non_empty_last_segments_len--

		trailing_slash = true

	}

	if segments[0] == ":" {
		if len(segments) < 2 {
			http.Error(w, "Blank system endpoint", http.StatusNotFound)
			return
		} else if len(segments) == 2 && redirect_with_slash(w, r) {
			return
		}

		switch segments[1] {
		case "static":
			static_handler.ServeHTTP(w, r)
			return
		case "source":
			source_handler.ServeHTTP(w, r)
			return
		}
	}

	params := make(map[string]any)
	params["global"] = global_data
	var _user_id int // 0 for none
	_user_id, params["username"], err = get_user_info_from_request(r)
	if errors.Is(err, http.ErrNoCookie) {
	} else if errors.Is(err, pgx.ErrNoRows) {
	} else if err != nil {
		http.Error(w, "Error getting user info from request: "+err.Error(), http.StatusInternalServerError)
		return
	}

	if _user_id == 0 {
		params["user_id"] = ""
	} else {
		params["user_id"] = strconv.Itoa(_user_id)
	}

	if segments[0] == ":" {
		switch segments[1] {
		case "login":
			handle_login(w, r, params)
			return
		case "users":
			handle_users(w, r, params)
			return
		default:
			http.Error(w, fmt.Sprintf("Unknown system module type: %s", segments[1]), http.StatusNotFound)
			return
		}
	}

	separator_index := -1
	for i, part := range segments {
		if part == ":" {
			separator_index = i
			break
		}
	}

	// TODO
	if separator_index != 1 {
		http.Error(w, "Subgroups haven't been implemented yet", http.StatusNotImplemented)
		return
	}

	switch {
	case non_empty_last_segments_len == 0:
		handle_index(w, r, params)
	case separator_index == -1:
		http.Error(w, "Group indexing hasn't been implemented yet", http.StatusNotImplemented)
	case non_empty_last_segments_len == separator_index+1:
		http.Error(w, "Group root hasn't been implemented yet", http.StatusNotImplemented)
	case non_empty_last_segments_len == separator_index+2:
		if redirect_with_slash(w, r) {
			return
		}
		module_type := segments[separator_index+1]
		params["group_name"] = segments[0]
		switch module_type {
		case "repos":
			handle_group_repos(w, r, params)
		default:
			http.Error(w, fmt.Sprintf("Unknown module type: %s", module_type), http.StatusNotFound)
		}
	default:
		module_type := segments[separator_index+1]
		module_name := segments[separator_index+2]
		group_name := segments[0]
		params["group_name"] = group_name
		switch module_type {
		case "repos":
			params["repo_name"] = module_name

			if non_empty_last_segments_len > separator_index+3 {
				switch segments[separator_index+3] {
				case "info":
					err = handle_repo_info(w, r, params)
					if err != nil {
						http.Error(w, err.Error(), http.StatusInternalServerError)
					}
					return
				case "git-upload-pack":
					err = handle_upload_pack(w, r, params)
					if err != nil {
						http.Error(w, err.Error(), http.StatusInternalServerError)
					}
					return
				}
			}

			params["ref_type"], params["ref_name"], err = get_param_ref_and_type(r)
			if err != nil {
				if errors.Is(err, err_no_ref_spec) {
					params["ref_type"] = ""
				} else {
					http.Error(w, "Error querying ref type: "+err.Error(), http.StatusInternalServerError)
					return
				}
			}

			// TODO: subgroups

			params["repo"], params["repo_description"], err = open_git_repo(r.Context(), group_name, module_name)
			if err != nil {
				http.Error(w, "Error opening repo: "+err.Error(), http.StatusInternalServerError)
				return
			}

			if non_empty_last_segments_len == separator_index+3 {
				if redirect_with_slash(w, r) {
					return
				}
				handle_repo_index(w, r, params)
				return
			}

			repo_feature := segments[separator_index+3]
			switch repo_feature {
			case "tree":
				params["rest"] = strings.Join(segments[separator_index+4:], "/")
				if len(segments) < separator_index+5 && redirect_with_slash(w, r) {
					return
				}
				handle_repo_tree(w, r, params)
			case "raw":
				params["rest"] = strings.Join(segments[separator_index+4:], "/")
				if len(segments) < separator_index+5 && redirect_with_slash(w, r) {
					return
				}
				handle_repo_raw(w, r, params)
			case "log":
				if non_empty_last_segments_len > separator_index+4 {
					http.Error(w, "Too many parameters", http.StatusBadRequest)
					return
				}
				if redirect_with_slash(w, r) {
					return
				}
				handle_repo_log(w, r, params)
			case "commit":

				if trailing_slash {
					http.Redirect(w, r, strings.TrimSuffix(r.URL.Path, "/"), http.StatusSeeOther)
					// TODO

				if redirect_without_slash(w, r) {

					return
				}
				params["commit_id"] = segments[separator_index+4]
				handle_repo_commit(w, r, params)
			default:
				http.Error(w, fmt.Sprintf("Unknown repo feature: %s", repo_feature), http.StatusNotFound)
			}
		default:
			http.Error(w, fmt.Sprintf("Unknown module type: %s", module_type), http.StatusNotFound)
		}
	}
}

var err_bad_request = errors.New("Bad Request")

package main

import (
	"errors"
	"net/http"
	"net/url"
	"strings"

	"go.lindenii.runxiyu.org/lindenii-common/misc"
)

var (
	err_duplicate_ref_spec = errors.New("Duplicate ref spec")
	err_no_ref_spec        = errors.New("No ref spec")
)

func get_param_ref_and_type(r *http.Request) (ref_type, ref string, err error) {
	qr := r.URL.RawQuery
	q, err := url.ParseQuery(qr)
	if err != nil {
		return
	}
	done := false
	for _, _ref_type := range []string{"commit", "branch", "tag"} {
		_ref, ok := q[_ref_type]
		if ok {
			if done {
				err = err_duplicate_ref_spec
				return
			} else {
				done = true
				if len(_ref) != 1 {
					err = err_duplicate_ref_spec
					return
				}
				ref = _ref[0]
				ref_type = _ref_type
			}
		}
	}
	if !done {
		err = err_no_ref_spec
	}
	return
}

func parse_request_uri(request_uri string) (segments []string, params url.Values, err error) {
	path, params_string, _ := strings.Cut(request_uri, "?")

	segments = strings.Split(strings.TrimPrefix(path, "/"), "/")

	for i, segment := range segments {
		segments[i], err = url.PathUnescape(segment)
		if err != nil {
			return nil, nil, misc.Wrap_one_error(err_bad_request, err)
		}
	}

	params, err = url.ParseQuery(params_string)
	if err != nil {
		return nil, nil, misc.Wrap_one_error(err_bad_request, err)
	}

	return
}

func redirect_with_slash(w http.ResponseWriter, r *http.Request) bool {
	request_uri := r.RequestURI

	path_end := strings.IndexAny(request_uri, "?#")
	var path, rest string
	if path_end == -1 {
		path = request_uri
	} else {
		path = request_uri[:path_end]
		rest = request_uri[path_end:]
	}

	if !strings.HasSuffix(path, "/") {
		http.Redirect(w, r, path+"/"+rest, http.StatusSeeOther)
		return true
	}
	return false
}

func redirect_without_slash(w http.ResponseWriter, r *http.Request) bool {
	request_uri := r.RequestURI

	path_end := strings.IndexAny(request_uri, "?#")
	var path, rest string
	if path_end == -1 {
		path = request_uri
	} else {
		path = request_uri[:path_end]
		rest = request_uri[path_end:]
	}

	if strings.HasSuffix(path, "/") {
		http.Redirect(w, r, strings.TrimSuffix(path, "/") + rest, http.StatusSeeOther)
		return true
	}
	return false
}