// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileContributor: Runxi Yu <https://runxiyu.org>

package main

import (
	"context"
	"errors"
	"io"
	"os"
	"strings"

	"github.com/jackc/pgx/v5/pgtype"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/object"

	"github.com/jackc/pgx/v5/pgtype"

)

// open_git_repo opens a git repository by group and repo name.
func open_git_repo(ctx context.Context, group_path []string, repo_name string) (repo *git.Repository, description string, repo_id int, err error) {
	var fs_path string

	err = database.QueryRow(ctx, `
WITH RECURSIVE group_path_cte AS (
	-- Start: match the first name in the path where parent_group IS NULL
	SELECT
		id,
		parent_group,
		name,
		1 AS depth
	FROM groups
	WHERE name = ($1::text[])[1]
		AND parent_group IS NULL

	UNION ALL

	-- Recurse: join next segment of the path
	SELECT
		g.id,
		g.parent_group,
		g.name,
		group_path_cte.depth + 1
	FROM groups g
	JOIN group_path_cte ON g.parent_group = group_path_cte.id
	WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
		AND group_path_cte.depth + 1 <= cardinality($1::text[])
)
SELECT
	r.filesystem_path,
	COALESCE(r.description, ''),
	r.id
FROM group_path_cte g
JOIN repos r ON r.group_id = g.id
WHERE g.depth = cardinality($1::text[])
	AND r.name = $2
	`, pgtype.FlatArray[string](group_path), repo_name).Scan(&fs_path, &description, &repo_id)
	if err != nil {
		return
	}

	repo, err = git.PlainOpen(fs_path)
	return
}

// go-git's tree entries are not friendly for use in HTML templates.
type display_git_tree_entry_t struct {
	Name       string
	Mode       string
	Size       int64
	Is_file    bool
	Is_subtree bool
}

func build_display_git_tree(tree *object.Tree) (display_git_tree []display_git_tree_entry_t) {
	for _, entry := range tree.Entries {
		display_git_tree_entry := display_git_tree_entry_t{}
		var err error
		var os_mode os.FileMode

		if os_mode, err = entry.Mode.ToOSFileMode(); err != nil {
			display_git_tree_entry.Mode = "x---------"
		} else {
			display_git_tree_entry.Mode = os_mode.String()
		}

		display_git_tree_entry.Is_file = entry.Mode.IsFile()

		if display_git_tree_entry.Size, err = tree.Size(entry.Name); err != nil {
			display_git_tree_entry.Size = 0
		}

		display_git_tree_entry.Name = strings.TrimPrefix(entry.Name, "/")

		display_git_tree = append(display_git_tree, display_git_tree_entry)
	}
	return display_git_tree
}

func get_recent_commits(repo *git.Repository, head_hash plumbing.Hash, number_of_commits int) (recent_commits []*object.Commit, err error) {
	var commit_iter object.CommitIter
	var this_recent_commit *object.Commit

	commit_iter, err = repo.Log(&git.LogOptions{From: head_hash})
	if err != nil {
		return nil, err
	}
	recent_commits = make([]*object.Commit, 0)
	defer commit_iter.Close()
	if number_of_commits < 0 {
		for {
			this_recent_commit, err = commit_iter.Next()
			if errors.Is(err, io.EOF) {
				return recent_commits, nil
			} else if err != nil {
				return nil, err
			}
			recent_commits = append(recent_commits, this_recent_commit)
		}
	} else {
		for range number_of_commits {
			this_recent_commit, err = commit_iter.Next()
			if errors.Is(err, io.EOF) {
				return recent_commits, nil
			} else if err != nil {
				return nil, err
			}
			recent_commits = append(recent_commits, this_recent_commit)
		}
	}
	return recent_commits, err
}

func get_patch_from_commit(commit_object *object.Commit) (parent_commit_hash plumbing.Hash, patch *object.Patch, err error) {
	var parent_commit_object *object.Commit
	var commit_tree *object.Tree

	parent_commit_object, err = commit_object.Parent(0)
	if errors.Is(err, object.ErrParentNotFound) {
		if commit_tree, err = commit_object.Tree(); err != nil {
			return
		}
		if patch, err = (&object.Tree{}).Patch(commit_tree); err != nil {
			return
		}
	} else if err != nil {
		return
	} else {
		parent_commit_hash = parent_commit_object.Hash
		if patch, err = parent_commit_object.Patch(commit_object); err != nil {
			return
		}
	}
	return
}

// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileContributor: Runxi Yu <https://runxiyu.org>

package main

import (
	"fmt"
	"net/http"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
)

func handle_group_index(w http.ResponseWriter, r *http.Request, params map[string]any) {
	var group_path []string
	var repos []name_desc_t
	var subgroups []name_desc_t
	var err error

	group_path = params["group_path"].([]string)

	// Repos
	var rows pgx.Rows
	rows, err = database.Query(r.Context(), `
	WITH RECURSIVE group_path_cte AS (
		SELECT
			id,
			parent_group,
			name,
			1 AS depth
		FROM groups
		WHERE name = ($1::text[])[1]
			AND parent_group IS NULL

		UNION ALL

		SELECT
			g.id,
			g.parent_group,
			g.name,
			group_path_cte.depth + 1
		FROM groups g
		JOIN group_path_cte ON g.parent_group = group_path_cte.id
		WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
			AND group_path_cte.depth + 1 <= cardinality($1::text[])
	)
	SELECT r.name, COALESCE(r.description, '')
	FROM group_path_cte c
	JOIN repos r ON r.group_id = c.id
	WHERE c.depth = cardinality($1::text[])
	`,
		pgtype.FlatArray[string](group_path),
	)
	if err != nil {
		http.Error(w, "Error getting repos: "+err.Error(), http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	for rows.Next() {
		var name, description string
		if err = rows.Scan(&name, &description); err != nil {
			http.Error(w, "Error getting repos: "+err.Error(), http.StatusInternalServerError)
			return
		}
		repos = append(repos, name_desc_t{name, description})
	}
	if err = rows.Err(); err != nil {
		http.Error(w, "Error getting repos: "+err.Error(), http.StatusInternalServerError)
		return
	}

	// Subgroups
	rows, err = database.Query(r.Context(), `
	WITH RECURSIVE group_path_cte AS (
		SELECT
			id,
			parent_group,
			name,
			1 AS depth
		FROM groups
		WHERE name = ($1::text[])[1]
			AND parent_group IS NULL

		UNION ALL

		SELECT
			g.id,
			g.parent_group,
			g.name,
			group_path_cte.depth + 1
		FROM groups g
		JOIN group_path_cte ON g.parent_group = group_path_cte.id
		WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
			AND group_path_cte.depth + 1 <= cardinality($1::text[])
	)
	SELECT g.name, COALESCE(g.description, '')
	FROM group_path_cte c
	JOIN groups g ON g.parent_group = c.id
	WHERE c.depth = cardinality($1::text[])
	`,
		pgtype.FlatArray[string](group_path),
	)
	if err != nil {
		http.Error(w, "Error getting subgroups: "+err.Error(), http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	for rows.Next() {
		var name, description string
		if err = rows.Scan(&name, &description); err != nil {
			http.Error(w, "Error getting subgroups: "+err.Error(), http.StatusInternalServerError)
			return
		}
		subgroups = append(subgroups, name_desc_t{name, description})
	}
	if err = rows.Err(); err != nil {
		http.Error(w, "Error getting subgroups: "+err.Error(), http.StatusInternalServerError)
		return
	}

	params["repos"] = repos
	params["subgroups"] = subgroups

	fmt.Println(group_path)

	render_template(w, "group", params)
}

// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileContributor: Runxi Yu <https://runxiyu.org>

package main

import (
	"io"
	"net/http"
	"os"
	"os/exec"

	"github.com/jackc/pgx/v5/pgtype"
)

func handle_upload_pack(w http.ResponseWriter, r *http.Request, params map[string]any) (err error) {
	var group_path []string
	var repo_name string
	var repo_path string
	var stdout io.ReadCloser
	var stdin io.WriteCloser
	var cmd *exec.Cmd

	group_path, repo_name = params["group_path"].([]string), params["repo_name"].(string)

	if err := database.QueryRow(r.Context(), `
	WITH RECURSIVE group_path_cte AS (
		-- Start: match the first name in the path where parent_group IS NULL
		SELECT
			id,
			parent_group,
			name,
			1 AS depth
		FROM groups
		WHERE name = ($1::text[])[1]
			AND parent_group IS NULL
	
		UNION ALL
	
		-- Recurse: jion next segment of the path
		SELECT
			g.id,
			g.parent_group,
			g.name,
			group_path_cte.depth + 1
		FROM groups g
		JOIN group_path_cte ON g.parent_group = group_path_cte.id
		WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
			AND group_path_cte.depth + 1 <= cardinality($1::text[])
	)
	SELECT r.filesystem_path
	FROM group_path_cte c
	JOIN repos r ON r.group_id = c.id
	WHERE c.depth = cardinality($1::text[])
		AND r.name = $2
	`,
		pgtype.FlatArray[string](group_path),
		repo_name,
	).Scan(&repo_path); err != nil {
		return err
	}

	w.Header().Set("Content-Type", "application/x-git-upload-pack-result")
	w.Header().Set("Connection", "Keep-Alive")
	w.Header().Set("Transfer-Encoding", "chunked")
	w.WriteHeader(http.StatusOK)

	cmd = exec.Command("git", "upload-pack", "--stateless-rpc", repo_path)
	cmd.Env = append(os.Environ(), "LINDENII_FORGE_HOOKS_SOCKET_PATH="+config.Hooks.Socket)
	if stdout, err = cmd.StdoutPipe(); err != nil {
		return err
	}
	cmd.Stderr = cmd.Stdout
	defer func() {
		_ = stdout.Close()
	}()

	if stdin, err = cmd.StdinPipe(); err != nil {
		return err
	}
	defer func() {
		_ = stdin.Close()
	}()

	if err = cmd.Start(); err != nil {
		return err
	}

	if _, err = io.Copy(stdin, r.Body); err != nil {
		return err
	}

	if err = stdin.Close(); err != nil {
		return err
	}

	if _, err = io.Copy(w, stdout); err != nil {
		return err
	}

	if err = cmd.Wait(); err != nil {
		return err
	}

	return nil
}

// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileContributor: Runxi Yu <https://runxiyu.org>

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)

	var segments []string
	var err error
	var non_empty_last_segments_len int
	var separator_index int
	params := make(map[string]any)

	if segments, _, err = parse_request_uri(r.RequestURI); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	non_empty_last_segments_len = len(segments)
	if segments[len(segments)-1] == "" {
		non_empty_last_segments_len--
	}

	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["url_segments"] = segments
	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
		}
	}

	params["separator_index"] = separator_index

	var group_path []string
	var module_type string
	var module_name string

	if separator_index > 0 {
		group_path = segments[:separator_index]
	} else {

		group_path = segments[:len(segments) - 1]

		group_path = segments[:len(segments)-1]

	}
	params["group_path"] = group_path

	switch {
	case non_empty_last_segments_len == 0:
		handle_index(w, r, params)
	case separator_index == -1:
		if redirect_with_slash(w, r) {
			return
		}
		handle_group_index(w, r, params)
	case non_empty_last_segments_len == separator_index+1:
		http.Error(w, "Illegal path 1", http.StatusNotImplemented)
		return
	case non_empty_last_segments_len == separator_index+2:
		http.Error(w, "Illegal path 2", http.StatusNotImplemented)
		return
	default:
		module_type = segments[separator_index+1]
		module_name = segments[separator_index+2]
		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":
					if err = handle_repo_info(w, r, params); err != nil {
						http.Error(w, err.Error(), http.StatusInternalServerError)
					}
					return
				case "git-upload-pack":
					if err = handle_upload_pack(w, r, params); err != nil {
						http.Error(w, err.Error(), http.StatusInternalServerError)
					}
					return
				}
			}

			if params["ref_type"], params["ref_name"], err = get_param_ref_and_type(r); 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

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

			fmt.Println(non_empty_last_segments_len, separator_index, segments)

			if non_empty_last_segments_len == separator_index+3 {
				if redirect_with_slash(w, r) {

				        return

					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 redirect_without_slash(w, r) {
					return
				}
				params["commit_id"] = segments[separator_index+4]
				handle_repo_commit(w, r, params)
			case "contrib":
				if redirect_with_slash(w, r) {
					return
				}
				switch non_empty_last_segments_len {
				case separator_index + 4:
					handle_repo_contrib_index(w, r, params)
				case separator_index + 5:
					params["mr_id"] = segments[separator_index+4]
					handle_repo_contrib_one(w, r, params)
				default:
					http.Error(w, "Too many parameters", http.StatusBadRequest)
				}
			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)
		}
	}
}