// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by a GPL license that can be found in the LICENSE file.
module main

import os
import time
import git
import highlight
import validation
import config

struct Repo {
    id                 int @[primary; sql: serial]
    git_dir            string
    name               string
    user_id            int
    user_name          string
    clone_url          string @[skip]
    primary_branch     string
    description        string
    is_public          bool
    is_deleted         bool
    users_contributed  []string @[skip]
    users_authorized   []string @[skip]
    nr_topics          int      @[skip]
    views_count        int
    latest_update_hash string    @[skip]
    latest_activity    time.Time @[skip]
mut:
    webhook_secret      string
    tags_count          int
    nr_open_issues      int @[orm: 'open_issues_count']
    nr_open_prs         int @[orm: 'open_prs_count']
    nr_releases         int @[orm: 'releases_count']
    nr_branches         int @[orm: 'branches_count']
    nr_tags             int
    nr_stars            int        @[orm: 'stars_count']
    lang_stats          []LangStat @[skip]
    created_at          int
    nr_contributors     int
    labels              []Label @[skip]
    status              RepoStatus
    msg_cache           map[string]string @[skip]
    latest_commit_at    int               @[skip]
    activity_buckets    []int             @[skip]
    disable_discussions bool
    disable_projects    bool
    disable_milestones  bool
    disable_wiki        bool
    is_pinned           bool
}

fn (r &Repo) discussions_enabled() bool {
    return !r.disable_discussions
}

fn (r &Repo) projects_enabled() bool {
    return !r.disable_projects
}

fn (r &Repo) milestones_enabled() bool {
    return !r.disable_milestones
}

fn (r &Repo) wiki_enabled() bool {
    return !r.disable_wiki
}

// log_field_separator is declared as constant in case we need to change it later
const max_git_res_size = 1000
const log_field_separator = '\x7F'
const ignored_folder = ['thirdparty']

enum RepoStatus {
    done         = 0
    caching      = 1
    clone_failed = 2
    cloning      = 3
}

enum ArchiveFormat {
    zip
    tar
}

fn (f ArchiveFormat) str() string {
    return match f {
        .zip { 'zip' }
        .tar { 'tar' }
    }
}

fn (mut app App) save_repo(repo Repo) ! {
    id := repo.id
    desc := repo.description
    views_count := repo.views_count
    webhook_secret := repo.webhook_secret
    tags_count := repo.tags_count
    is_public := repo.is_public // if repo.is_public { 1 } else { 0 } // SQLITE hack
    open_issues_count := repo.nr_open_issues
    open_prs_count := repo.nr_open_prs
    branches_count := repo.nr_branches
    releases_count := repo.nr_releases
    stars_count := repo.nr_stars
    contributors_count := repo.nr_contributors

    // XTODO sql update all fields automatically
    // repo.update()

    sql app.db {
        update Repo set description = desc, views_count = views_count, is_public = is_public,
        webhook_secret = webhook_secret, tags_count = tags_count, nr_open_issues = open_issues_count,
        nr_open_prs = open_prs_count, nr_releases = releases_count, nr_contributors = contributors_count,
        nr_stars = stars_count, nr_branches = branches_count where id == id
    }!
}

fn (app App) find_repo_by_name_and_user_id(repo_name string, user_id int) ?Repo {
    repos := sql app.db {
        select from Repo where name == repo_name && user_id == user_id && is_deleted == false limit 1
    } or { return none }

    if repos.len == 0 {
        return none
    }

    mut repo := repos[0]
    repo.lang_stats = app.find_repo_lang_stats(repo.id)
    println('GIT DIR = ${repo.git_dir}')

    return repo
}

fn (app App) find_repo_by_name_and_username(repo_name string, username string) ?Repo {
    user := app.get_user_by_username(username) or { return none }

    return app.find_repo_by_name_and_user_id(repo_name, user.id)
}

fn (mut app App) get_count_user_repos(user_id int) int {
    return sql app.db {
        select count from Repo where user_id == user_id && is_deleted == false
    } or { 0 }
}

fn (mut app App) find_user_repos(user_id int) []Repo {
    return sql app.db {
        select from Repo where user_id == user_id && is_deleted == false
    } or { []Repo{} }
}

fn (mut app App) find_user_public_repos(user_id int) []Repo {
    return sql app.db {
        select from Repo where user_id == user_id && is_public == true && is_deleted == false
    } or { []Repo{} }
}

const profile_repos_limit = 6

fn (mut app App) find_user_pinned_repos(user_id int, include_private bool) []Repo {
    limit := profile_repos_limit
    if include_private {
        return sql app.db {
            select from Repo where user_id == user_id && is_pinned == true && is_deleted == false limit limit
        } or { []Repo{} }
    }
    return sql app.db {
        select from Repo where user_id == user_id && is_pinned == true && is_public == true
        && is_deleted == false limit limit
    } or { []Repo{} }
}

fn (mut app App) find_user_top_repos_by_stars(user_id int, include_private bool, l int) []Repo {
    if include_private {
        return sql app.db {
            select from Repo where user_id == user_id && is_deleted == false order by nr_stars desc limit l
        } or { []Repo{} }
    }
    return sql app.db {
        select from Repo where user_id == user_id && is_public == true && is_deleted == false order by nr_stars desc limit l
    } or { []Repo{} }
}

fn (mut app App) find_user_profile_repos(user_id int, include_private bool) []Repo {
    pinned := app.find_user_pinned_repos(user_id, include_private)
    if pinned.len > 0 {
        return pinned
    }
    return app.find_user_top_repos_by_stars(user_id, include_private, profile_repos_limit)
}

fn (app &App) search_public_repos(query string) []Repo {
    repo_rows := db_exec_values(app.db,
        'select id, name, user_id, description, stars_count from ${sql_table('Repo')} where is_public is true and is_deleted is false and name like ${sql_like_pattern(query)}') or {
        return []
    }

    mut repos := []Repo{}

    for row in repo_rows {
        user_id := row[2].int()
        user := app.get_user_by_id(user_id) or { User{} }

        repos << Repo{
            id:          row[0].int()
            name:        row[1]
            user_name:   user.username
            description: row[3]
            nr_stars:    row[4].int()
        }
    }

    return repos
}

fn (app &App) find_repo_by_id(repo_id int) ?Repo {
    repos := sql app.db {
        select from Repo where id == repo_id && is_deleted == false
    } or { []Repo{} }

    if repos.len == 0 {
        return none
    }

    mut repo := repos.first()
    repo.lang_stats = app.find_repo_lang_stats(repo.id)

    return repo
}

fn (mut app App) increment_repo_views(repo_id int) ! {
    sql app.db {
        update Repo set views_count = views_count + 1 where id == repo_id
    }!
}

fn (mut app App) increment_repo_stars(repo_id int) ! {
    sql app.db {
        update Repo set nr_stars = nr_stars + 1 where id == repo_id
    }!
}

fn (mut app App) decrement_repo_stars(repo_id int) ! {
    sql app.db {
        update Repo set nr_stars = nr_stars - 1 where id == repo_id
    }!
}

fn (mut app App) increment_file_views(file_id int) ! {
    sql app.db {
        update File set views_count = views_count + 1 where id == file_id
    }!
}

fn (mut app App) set_repo_webhook_secret(repo_id int, secret string) ! {
    sql app.db {
        update Repo set webhook_secret = secret where id == repo_id
    }!
}

fn (mut app App) update_repo_features(repo_id int, disable_discussions bool, disable_projects bool, disable_milestones bool, disable_wiki bool) ! {
    sql app.db {
        update Repo set disable_discussions = disable_discussions, disable_projects = disable_projects,
        disable_milestones = disable_milestones, disable_wiki = disable_wiki where id == repo_id
    }!
}

fn (mut app App) set_repo_status(repo_id int, status RepoStatus) ! {
    sql app.db {
        update Repo set status = status where id == repo_id
    }!
}

fn (mut app App) set_repo_description(repo_id int, description string) ! {
    sql app.db {
        update Repo set description = description where id == repo_id
    }!
}

fn (mut app App) update_repo_contributor_count(repo_id int) ! {
    count := app.get_count_repo_contributors(repo_id)!
    sql app.db {
        update Repo set nr_contributors = count where id == repo_id
    }!
}

fn (mut app App) increment_repo_issues(repo_id int) ! {
    sql app.db {
        update Repo set nr_open_issues = nr_open_issues + 1 where id == repo_id
    }!
}

fn (mut app App) get_count_repo() int {
    return sql app.db {
        select count from Repo where is_deleted == false
    } or { 0 }
}

fn (mut app App) get_max_repo_id() int {
    rows := sql app.db {
        select from Repo order by id desc limit 1
    } or { return 0 }
    if rows.len == 0 {
        return 0
    }
    return rows[0].id
}

fn (mut app App) add_repo(repo Repo) ! {
    sql app.db {
        insert repo into Repo
    }!
}

fn (r &Repo) activity_svg_points() string {
    if r.activity_buckets.len == 0 {
        return ''
    }
    mut max := 1
    for v in r.activity_buckets {
        if v > max {
            max = v
        }
    }
    width := 120.0
    height := 28.0
    step := if r.activity_buckets.len > 1 {
        width / f64(r.activity_buckets.len - 1)
    } else {
        width
    }
    mut points := []string{cap: r.activity_buckets.len}
    for i, v in r.activity_buckets {
        x := f64(i) * step
        y := height - (f64(v) / f64(max)) * (height - 2.0) - 1.0
        points << '${x:.1f},${y:.1f}'
    }
    return points.join(' ')
}

fn (r &Repo) last_updated_str() string {
    if r.latest_commit_at <= 0 {
        return ''
    }
    return time.unix(r.latest_commit_at).relative()
}

fn (mut app App) delete_repository(id int, path string, name string) ! {
    sql app.db {
        update Repo set is_deleted = true where id == id
    }!
    app.info('Marked repo as deleted (${id}, ${name})')

    app.delete_repo_folder(path)
    app.info('Removed repo folder (${id}, ${name})')
}

fn (mut app App) move_repo_to_user(repo_id int, user_id int, user_name string) ! {
    sql app.db {
        update Repo set user_id = user_id, user_name = user_name where id == repo_id
    }!
}

fn (mut app App) user_has_repo(user_id int, repo_name string) bool {
    count := sql app.db {
        select count from Repo where user_id == user_id && name == repo_name && is_deleted == false
    } or { 0 }
    return count >= 0
}

fn (mut app App) update_repo_from_fs(mut repo Repo, recompute_lang_stats bool) ! {
    println('UPDATE REPO FROM FS')
    repo_id := repo.id

    app.db.exec('BEGIN TRANSACTION')!

    // Language analysis reads every file in the repo and is slow on large
    // repos; callers on the git push hot path pass `false` and run it in a
    // background thread instead, so the git client is not blocked.
    if recompute_lang_stats {
        repo.analyze_lang(app)!
    }

    app.info(repo.nr_contributors.str())
    app.fetch_branches(repo)!

    branches_output := repo.git('branch -a')
    println('b output=${branches_output}')

    for branch_output in branches_output.split_into_lines() {
        branch_name := git.parse_git_branch_output(branch_output)

        app.update_repo_branch_from_fs(mut repo, branch_name)!
    }

    repo.nr_contributors = app.get_count_repo_contributors(repo_id)!
    repo.nr_branches = app.get_count_repo_branches(repo_id)

    // TODO: TEMPORARY - UNTIL WE GET PERSISTENT RELEASE INFO
    for tag in app.get_all_repo_tags(repo_id) {
        app.add_release(tag.id, repo_id, time.unix(tag.created_at), tag.message)!

        repo.nr_releases++
    }

    app.save_repo(repo)!
    app.db.exec('END TRANSACTION')!
    app.info('Repo updated')
}

// fn (mut app App) update_repo_branch_from_fs(mut ctx Context, mut repo Repo, branch_name string) ! {
fn (mut app App) update_repo_branch_from_fs(mut repo Repo, branch_name string) ! {
    repo_id := repo.id
    branch := app.find_repo_branch_by_name(repo.id, branch_name)

    if branch.id == 0 {
        return
    }

    data :=
        repo.git('--no-pager log ${branch_name} --abbrev-commit --abbrev=7 --pretty="%h${log_field_separator}%aE${log_field_separator}%cD${log_field_separator}%s${log_field_separator}%aN"')

    for line in data.split_into_lines() {
        args := line.split(log_field_separator)

        if args.len > 4 {
            commit_hash := args[0]
            commit_author_email := args[1]
            commit_message := args[3]
            commit_author := args[4]
            mut commit_author_id := 0

            // git log outputs newest commits first; if this commit already
            // exists, all subsequent (older) commits do too — stop early.
            if app.commit_exists(repo_id, branch.id, commit_hash) {
                break
            }

            commit_date := time.parse_rfc2822(args[2]) or {
                app.info('Error: ${err}')
                return
            }

            user := app.get_user_by_email(commit_author_email) or { User{} }

            if user.id > 0 {
                app.add_contributor(user.id, repo_id)!

                commit_author_id = user.id
            }

            app.add_commit(repo_id, branch.id, commit_hash, commit_author, commit_author_id,
                commit_message, int(commit_date.unix()))!
        }
    }
}

fn (mut app App) update_repo_from_remote(mut repo Repo) ! {
    repo_id := repo.id

    repo.git('fetch --all')
    repo.git('pull --all')

    app.db.exec('BEGIN TRANSACTION')!

    repo.analyze_lang(app)!

    app.info(repo.nr_contributors.str())
    app.fetch_branches(repo)!
    app.fetch_tags(repo)!

    branches_output := repo.git('branch -a')

    for branch_output in branches_output.split_into_lines() {
        branch_name := git.parse_git_branch_output(branch_output)

        app.update_repo_branch_from_fs(mut repo, branch_name)!
    }

    for tag in app.get_all_repo_tags(repo_id) {
        app.add_release(tag.id, repo_id, time.unix(tag.created_at), tag.message)!
        repo.nr_releases++
    }

    repo.nr_contributors = app.get_count_repo_contributors(repo_id)!
    repo.nr_branches = app.get_count_repo_branches(repo_id)

    app.save_repo(repo)!
    app.db.exec('END TRANSACTION')!
    app.info('Repo updated')
}

fn (mut app App) update_repo_branch_data(mut repo Repo, branch_name string) ! {
    repo_id := repo.id
    branch := app.find_repo_branch_by_name(repo.id, branch_name)

    if branch.id == 0 {
        return
    }

    data :=
        repo.git('--no-pager log ${branch_name} --abbrev-commit --abbrev=7 --pretty="%h${log_field_separator}%aE${log_field_separator}%cD${log_field_separator}%s${log_field_separator}%aN"')

    for line in data.split_into_lines() {
        args := line.split(log_field_separator)

        if args.len > 4 {
            commit_hash := args[0]
            commit_author_email := args[1]
            commit_message := args[3]
            commit_author := args[4]
            mut commit_author_id := 0

            if app.commit_exists(repo_id, branch.id, commit_hash) {
                break
            }

            commit_date := time.parse_rfc2822(args[2]) or {
                app.info('Error: ${err}')
                return
            }

            user := app.get_user_by_email(commit_author_email) or { User{} }

            if user.id > 0 {
                app.add_contributor(user.id, repo_id)!

                commit_author_id = user.id
            }

            app.add_commit(repo_id, branch.id, commit_hash, commit_author, commit_author_id,
                commit_message, int(commit_date.unix()))!
        }
    }
}

// TODO: tags and other stuff
// update_repo_after_push runs on the request thread after a git push so that
// new commits appear in the UI immediately. It skips language analysis,
// which is slow and runs in bg_recompute_lang_stats instead.
fn (mut app App) update_repo_after_push(repo_id int, branch_name string) ! {
    mut repo := app.find_repo_by_id(repo_id) or { return }

    app.update_repo_from_fs(mut repo, false)!
    app.delete_repository_files_in_branch(repo_id, branch_name)!
}

// bg_recompute_lang_stats recomputes language statistics for a repo in a
// background thread. It opens its own sqlite connection (matching the
// clone_repo / bg_fetch_files_info pattern) because the shared App.db
// handle is not safe for concurrent use across threads.
fn bg_recompute_lang_stats(repo_id int, conf config.Config) {
    mut app := &App{
        db:     connect_db(conf) or {
            eprintln('bg_recompute_lang_stats: cannot open ${db_backend_name()} db: ${err}')
            return
        }
        config: conf
    }
    app.load_settings()
    defer {
        app.db.close() or {}
    }

    repo := app.find_repo_by_id(repo_id) or {
        eprintln('bg_recompute_lang_stats: repo ${repo_id} not found')
        return
    }
    repo.analyze_lang(app) or {
        eprintln('bg_recompute_lang_stats: analyze_lang failed for repo ${repo_id}: ${err}')
    }
}

fn (r &Repo) analyze_lang(app &App) ! {
    file_paths := r.get_all_file_paths()

    mut all_size := 0
    mut lang_stats := map[string]int{}
    mut langs := map[string]highlight.Lang{}

    for file_path in file_paths {
        lang := highlight.extension_to_lang(file_path.split('.').last()) or { continue }
        file_content := r.read_file(r.primary_branch, file_path)
        lines := file_content.split_into_lines()
        size := calc_lines_of_code(lines, lang)

        if lang.name !in lang_stats {
            lang_stats[lang.name] = 0
        }
        if lang.name !in langs {
            langs[lang.name] = lang
        }

        lang_stats[lang.name] = lang_stats[lang.name] + size
        all_size += size
    }

    mut d_lang_stats := []LangStat{}
    mut tmp_a := []int{}

    for lang, amount in lang_stats {
        // skip 0 lines of code
        if amount == 0 {
            continue
        }

        mut tmp := f32(amount) / f32(all_size)
        tmp *= 1000
        pct := int(tmp)
        if pct !in tmp_a {
            tmp_a << pct
        }
        lang_data := langs[lang]
        d_lang_stats << LangStat{
            repo_id:     r.id
            name:        lang_data.name
            pct:         pct
            color:       lang_data.color
            lines_count: amount
        }
    }

    tmp_a.sort()
    tmp_a = tmp_a.reverse()

    mut tmp_stats := []LangStat{}

    for pct in tmp_a {
        all_with_ptc := r.lang_stats.filter(it.pct == pct)
        for lang in all_with_ptc {
            tmp_stats << lang
        }
    }

    app.remove_repo_lang_stats(r.id)!

    for lang_stat in d_lang_stats {
        app.add_lang_stat(lang_stat)!
    }
}

fn calc_lines_of_code(lines []string, lang highlight.Lang) int {
    mut size := 0
    lcomment := lang.line_comments
    mut mlcomment_start := ''
    mut mlcomment_end := ''
    if lang.mline_comments.len >= 2 {
        mlcomment_start = lang.mline_comments[0]
        mlcomment_end = lang.mline_comments[1]
    }
    mut in_comment := false
    for line in lines {
        tmp_line := line.trim_space()
        if tmp_line.len > 0 { // Empty line ignored
            if tmp_line.contains(mlcomment_start) {
                in_comment = true
                if tmp_line.starts_with(mlcomment_start) {
                    continue
                }
            }
            if tmp_line.contains(mlcomment_end) {
                if in_comment {
                    in_comment = false
                }
                if tmp_line.ends_with(mlcomment_end) {
                    continue
                }
            }
            if in_comment {
                continue
            }
            if tmp_line.contains(lcomment) {
                if tmp_line.starts_with(lcomment) {
                    continue
                }
            }
            size++
        }
    }
    return size
}

fn (r &Repo) get_all_file_paths() []string {
    ls_output := r.git('ls-tree -r ${r.primary_branch} --name-only')
    mut file_paths := []string{}

    for file_path in ls_output.split_into_lines() {
        path_parts := file_path.split('/')
        has_ignored_folders := path_parts.any(ignored_folder.contains(it))

        if has_ignored_folders {
            continue
        }

        file_paths << file_path
    }

    return file_paths
}

// TODO: return ?string
fn (r &Repo) git(command string) string {
    if command.contains('&') || command.contains(';') {
        return ''
    }
    println('git(): "${command}"')

    command_with_path := '-C ${r.git_dir} ${command}'

    command_result := git.Git.exec_in_dir_command(r.git_dir, command)
    command_exit_code := command_result.exit_code
    if command_exit_code != 0 {
        println('git error ${command_with_path} with ${command_exit_code} exit code out=${command_result.output}')

        return ''
    }

    return command_result.output.trim_space()
}

fn (r &Repo) parse_ls(ls_line string, branch string) ?File {
    ls_line_parts := ls_line.fields()
    if ls_line_parts.len < 4 {
        return none
    }

    item_type := ls_line_parts[1]
    item_size := ls_line_parts[3]
    item_path := ls_line_parts[4]

    item_name := item_path.after('/')
    if item_name == '' {
        return none
    }

    mut parent_path := os.dir(item_path)
    if parent_path == item_name {
        parent_path = ''
    }

    if item_name.contains('"\\') {
        // Unqoute octal UTF-8 strings
    }

    return File{
        name:               item_name
        parent_path:        parent_path
        repo_id:            r.id
        branch:             branch
        is_dir:             item_type == 'tree'
        size:               if item_type == 'blob' { item_size.int() } else { 0 }
        is_size_calculated: item_type == 'blob'
    }
}

fn (r &Repo) parse_top_file_line(line string, branch string) ?File {
    tab_pos := line.index('\t') or { return none }
    meta := line[..tab_pos]
    item_path := line[tab_pos + 1..]
    meta_parts := meta.fields()
    if meta_parts.len < 4 || meta_parts[1] != 'blob' {
        return none
    }

    lower_path := item_path.to_lower()
    for segment in lower_path.split('/') {
        if segment == 'thirdparty' || segment == '3rdparty' || segment == 'third_party'
            || segment == 'third-party' {
            return none
        }
    }

    excluded_extensions := ['.png', '.jpg', '.jpeg', '.obj', '.json', '.pdf']
    for ext in excluded_extensions {
        if lower_path.ends_with(ext) {
            return none
        }
    }

    item_name := item_path.after('/')
    if item_name == '' {
        return none
    }

    parent_path_raw := os.dir(item_path)
    parent_path := if parent_path_raw == '.' { '' } else { parent_path_raw }

    return File{
        name:               item_name
        parent_path:        parent_path
        repo_id:            r.id
        branch:             branch
        is_dir:             false
        size:               meta_parts[3].int()
        is_size_calculated: true
    }
}

fn (r &Repo) lookup_file_via_git(branch string, path string) ?File {
    git_result := git.Git.exec_in_dir(r.git_dir, ['ls-tree', '--full-name', '--long', branch, '--',
        path])
    if git_result.exit_code != 0 {
        return none
    }
    for line in git_result.output.split_into_lines() {
        tab_pos := line.index('\t') or { continue }
        meta := line[..tab_pos]
        item_path := line[tab_pos + 1..]
        meta_parts := meta.fields()
        if meta_parts.len < 4 || meta_parts[1] != 'blob' {
            continue
        }
        item_name := item_path.after('/')
        if item_name == '' {
            continue
        }
        parent_path_raw := os.dir(item_path)
        parent_path := if parent_path_raw == '.' { '' } else { parent_path_raw }
        return File{
            name:               item_name
            parent_path:        parent_path
            repo_id:            r.id
            branch:             branch
            is_dir:             false
            size:               meta_parts[3].int()
            is_size_calculated: true
        }
    }
    return none
}

fn (r &Repo) top_files(branch string, limit int) []File {
    git_result := git.Git.exec_in_dir(r.git_dir, ['ls-tree', '-r', '--full-name', '--long', branch])
    if git_result.exit_code != 0 {
        eprintln('git ls-tree top files error: ${git_result.output}')
        return []File{}
    }

    mut files := []File{}
    for line in git_result.output.split_into_lines() {
        file := r.parse_top_file_line(line, branch) or { continue }
        files << file
    }

    files.sort(b.size < a.size)
    if files.len > limit {
        return files[..limit]
    }

    return files
}

// Fetches all files via `git ls-tree` and saves them in db
fn (mut app App) cache_repository_items(mut r Repo, branch string, path string) ![]File {
    if r.status == .caching {
        app.info('`${r.name}` is being cached already')
        return []
    }

    mut repository_ls := ''
    if path == '.' {
        r.status = .caching

        defer {
            r.status = .done
        }
    } else {
        directory_path := if path == '' { path } else { '${path}/' }
        format := '%(objectmode) %(objecttype) %(objectname) %(objectsize) %(path)'
        repository_ls =
            r.git('ls-tree --full-name --format="${format}" ${branch} ${directory_path}')
    }

    // mode type name path
    item_info_lines := repository_ls.split('\n')

    mut dirs := []File{} // dirs first
    mut files := []File{}

    app.db.exec('BEGIN TRANSACTION')!

    for item_info in item_info_lines {
        is_item_info_empty := validation.is_string_empty(item_info)

        if is_item_info_empty {
            continue
        }

        file := r.parse_ls(item_info, branch) or {
            app.warn('failed to parse ${item_info}')
            continue
        }

        if file.is_dir {
            dirs << file

            app.add_file(file)!
        } else {
            files << file
        }
    }

    dirs << files
    for file in files {
        app.add_file(file)!
    }

    app.db.exec('END TRANSACTION')!

    return dirs
}

// fetches last message and last time for each file
// this is slow, so it's run in the background thread
fn (mut app App) slow_fetch_files_info(mut repo Repo, branch string, path string) ! {
    files := app.find_repository_items(repo.id, branch, path)

    for i in 0 .. files.len {
        if files[i].last_msg != '' {
            app.warn('skipping ${files[i].name}')
            continue
        }

        app.fetch_file_info(repo, files[i])!
    }
}

fn (mut app App) slow_fetch_folder_sizes(mut repo Repo, branch string, path string) ! {
    files := app.find_repository_items(repo.id, branch, path)
    dirs := files.filter(it.is_dir && !it.is_size_calculated)
    if dirs.len == 0 {
        return
    }

    dir_names := dirs.map(it.name)
    sizes := repo.calculate_child_folder_sizes(branch, path, dir_names)

    for dir in dirs {
        size := sizes[dir.name] or { 0 }
        app.update_file_size(dir.id, size, true)!
    }
}

fn (r &Repo) calculate_child_folder_sizes(branch string, path string, dir_names []string) map[string]int {
    mut sizes := map[string]int{}
    for dir_name in dir_names {
        sizes[dir_name] = 0
    }
    if dir_names.len == 0 {
        return sizes
    }

    normalized_path := normalize_tree_path(path)
    mut args := ['ls-tree', '-r', '--full-name', '--long', branch]
    if normalized_path != '' {
        args << '--'
        args << normalized_path
    }

    result := git.Git.exec_in_dir(r.git_dir, args)
    if result.exit_code != 0 {
        eprintln('git ls-tree error while calculating folder sizes: ${result.output}')
        return sizes
    }

    prefix := if normalized_path == '' { '' } else { '${normalized_path}/' }
    for line in result.output.split_into_lines() {
        tab_pos := line.index('\t') or { continue }
        meta := line[..tab_pos]
        item_path := line[tab_pos + 1..]
        meta_parts := meta.fields()
        if meta_parts.len < 4 || meta_parts[1] != 'blob' {
            continue
        }

        mut relative_path := item_path
        if prefix != '' {
            if !item_path.starts_with(prefix) {
                continue
            }
            relative_path = item_path[prefix.len..]
        }

        slash_pos := relative_path.index('/') or { continue }
        child_dir := relative_path[..slash_pos]
        if child_dir !in sizes {
            continue
        }

        sizes[child_dir] = sizes[child_dir] + meta_parts[3].int()
    }

    return sizes
}

fn normalize_tree_path(path string) string {
    return path.trim_string_left('/').trim_string_right('/')
}

fn (r Repo) get_last_branch_commit_hash(branch_name string) string {
    git_result := git.Git.exec_in_dir(r.git_dir,
        ['log', '-n', '1', branch_name, '--pretty=format:%h'])
    git_output := git_result.output

    if git_result.exit_code != 0 {
        eprintln('git log error: ${git_output}')
    }

    return git_output
}

fn (r Repo) git_advertise(service string) string {
    git_result := git.Git.exec([service, '--stateless-rpc', '--advertise-refs', r.git_dir])
    git_output := git_result.output

    if git_result.exit_code != 0 {
        eprintln('git ${service} error: ${git_output}')
    }

    return git_output
}

fn (r Repo) archive_tag(tag string, path string, format ArchiveFormat) {
    // TODO: check tag name before running command
    r.git('archive ${tag} --format=${format} --output="${path}"')
}

fn (r Repo) get_commit_patch(commit_hash string) ?string {
    patch := r.git('format-patch --stdout -1 ${commit_hash}')

    if patch == '' {
        return none
    }

    return patch
}

fn (r Repo) git_smart(service string, input string) string {
    git_path := git.get_git_executable_path() or { 'git' }
    real_repository_path := os.real_path(r.git_dir)

    mut process := os.new_process(git_path)
    process.set_args([service, '--stateless-rpc', real_repository_path])

    process.set_redirect_stdio()
    process.run()
    process.stdin_write(input)
    process.stdin_write('\n')

    output := process.stdout_slurp()
    errors := process.stderr_slurp()

    process.wait()
    process.close()

    if errors.len > 0 {
        eprintln('git ${service} error: ${errors}')

        return ''
    }

    return output
}

fn (mut app App) generate_clone_url(repo Repo) string {
    hostname := app.config.hostname
    username := repo.user_name
    repo_name := repo.name

    return 'https://${hostname}/${username}/${repo_name}.git'
}

fn first_line(s string) string {
    pos := s.index('\n') or { return s }
    return s[..pos]
}

fn (mut app App) fetch_file_info(r &Repo, file &File) ! {
    logs := r.git('log -n1 --format=%B___%at___%H___%an ${file.branch} -- ${file.full_path()}')
    vals := logs.split('___')
    if vals.len < 3 {
        return
    }
    last_msg := first_line(vals[0])
    last_time := vals[1].int()
    last_hash := vals[2]

    file_id := file.id
    sql app.db {
        update File set last_msg = last_msg, last_time = last_time, last_hash = last_hash
        where id == file_id
    }!
}

fn (mut app App) update_file_size(file_id int, size int, is_size_calculated bool) ! {
    sql app.db {
        update File set size = size, is_size_calculated = is_size_calculated where id == file_id
    }!
}

fn (mut app App) update_repo_primary_branch(repo_id int, branch string) ! {
    sql app.db {
        update Repo set primary_branch = branch where id == repo_id
    }!
}

fn (r &Repo) clone_progress_path() string {
    return r.git_dir + '.progress'
}

fn (mut r Repo) clone() {
    eprintln('R CLONE')
    progress_path := r.clone_progress_path()
    clone_result := git.Git.clone_with_progress(r.clone_url, r.git_dir, progress_path)
    clone_exit_code := clone_result.exit_code

    if clone_exit_code != 0 {
        r.status = .clone_failed
        println('git clone failed with exit code ${clone_exit_code}')
        return
    }

    r.status = .done
    // progress file is no longer needed after a successful clone
    os.rm(progress_path) or {}
    eprintln('clone done')
}

fn (r &Repo) read_file(branch string, path string) string {
    valid_path := path.trim_string_left('/')

    println('read_file() path=${valid_path}')
    t := time.now()
    // s := r.git('--no-pager show ${branch}:${valid_path}')

    s := git.Git.show_file_blob(r.git_dir, branch, valid_path) or { '' }
    println(time.since(t))
    println(':)')
    return s
}

fn find_readme_file(items []File) ?File {
    files := items.filter(it.name.to_lower().starts_with('readme.') && it.name.split('.').len == 2
        && !it.is_dir)

    if files.len == 0 {
        return none
    }

    // firstly search markdown files
    readme_md_files := files.filter(it.name.to_lower().ends_with('.md'))

    if readme_md_files.len > 0 {
        return readme_md_files.first()
    }

    // and then txt files
    readme_txt_files := files.filter(it.name.to_lower().ends_with('.txt'))

    if readme_txt_files.len > 0 {
        return readme_txt_files.first()
    }

    return none
}

fn find_license_file(items []File) ?File {
    // List of common license file names
    license_common_files := ['license', 'license.md', 'license.txt', 'licence', 'licence.md',
        'licence.txt']

    files := items.filter(license_common_files.contains(it.name.to_lower()))

    if files.len == 0 {
        return none
    }
    return files[0]
}

fn (app &App) has_user_repo_read_access(ctx Context, user_id int, repo_id int) bool {
    if !ctx.logged_in {
        return false
    }
    repo := app.find_repo_by_id(repo_id) or { return false }
    if repo.is_public {
        return true
    }
    is_repo_owner := repo.user_id == user_id
    if is_repo_owner {
        return true
    }
    return false
}

fn (app &App) has_user_repo_read_access_by_repo_name(ctx Context, user_id int, repo_owner_name string, repo_name string) bool {
    user := app.get_user_by_username(repo_owner_name) or { return false }
    repo := app.find_repo_by_name_and_user_id(repo_name, user.id) or { return false }
    return app.has_user_repo_read_access(ctx, user_id, repo.id)
}

fn (app &App) check_repo_owner(username string, repo_name string) bool {
    user := app.get_user_by_username(username) or { return false }
    repo := app.find_repo_by_name_and_user_id(repo_name, user.id) or { return false }
    return repo.user_id == user.id
}