const pj_module_dir = (path self | path dirname)
const pj_cache_dir = ($pj_module_dir | path join '..' 'cache')
const pj_completion_base_dir = ($pj_cache_dir | path join 'nu_scripts' 'custom-completions')
const pj_completion_commands = [git ssh cargo uv rustup make pytest rg tar vscode winget zig]
const pj_completion_noop_module = ($pj_cache_dir | path join 'noop.nu')
const pj_completion_registry_module = ($pj_cache_dir | path join 'pj_completions_registry.nu')
const pj_completion_bootstrap_module = if ($pj_completion_registry_module | path exists) {
    $pj_completion_registry_module
} else {
    $pj_completion_noop_module
}

def _pj_completion_script_path [name: string] {
    ($pj_completion_base_dir | path join $name $"($name)-completions.nu")
}

def _pj_required_completion_files [] {
    $pj_completion_commands | each {|name|
        {
            command: $name
            file: (_pj_completion_script_path $name)
        }
    }
}

def _pj_completion_registry_lines [] {
    let header = [
        "# Auto-generated by `pj completion sync`."
        "# Edit pj_completion_commands in pj_completions.nu, then re-run sync."
        "const pj_registry_dir = (path self | path dirname)"
        "const pj_completion_base_dir = ($pj_registry_dir | path join 'nu_scripts' 'custom-completions')"
        "const pj_completion_noop_module = ($pj_registry_dir | path join 'noop.nu')"
        ""
    ]

    let lines = ($pj_completion_commands | each {|name|
        [
            (
                "export use (if ((($pj_completion_base_dir | path join '"
                + $name
                + "' '"
                + $name
                + "-completions.nu') | path exists)) { ($pj_completion_base_dir | path join '"
                + $name
                + "' '"
                + $name
                + "-completions.nu') } else { $pj_completion_noop_module }) *"
            )
            ""
        ]
    } | flatten)

    ($header | append $lines)
}

def _pj_completion_help [] {
    print "pj completion commands:"
    print "  pj completion             Clone/update cache and check required completion files."
    print "  pj completion -u          Update cached nu_scripts repository."
    print "  pj completion -f          Force re-clone cached nu_scripts repository."
    print "  pj completion sync        Regenerate cache registry and restart Nushell."
    print "  pj completion -s          Same as `pj completion sync`."
    print "  pj completion -h          Show this help message."
}

export def "pj completion sync" [
    --help(-h)
] {
    if $help {
        _pj_completion_help
        return
    }

    mkdir $pj_cache_dir
    let content = ((_pj_completion_registry_lines) | str join "\n")
    $content | save -f $pj_completion_registry_module
    print $"[pj completion] synced: ($pj_completion_registry_module)"
    print "[pj completion] restarting Nushell..."
    exec nu
}

export def "pj completion" [
    --update(-u) # Pull latest changes when repo already exists.
    --force(-f) # Re-clone even when repo already exists.
    --sync(-s) # Regenerate static registry and restart Nushell.
    --help(-h) # Show help.
] {
    if $help {
        _pj_completion_help
        return
    }

    if $sync {
        pj completion sync
        return
    }

    let repo_url = "https://github.com/nushell/nu_scripts.git"
    let cache_dir = if ('NU_POLYJUICE_PATH' in $env) {
        ($env.NU_POLYJUICE_PATH | path join 'cache')
    } else {
        (pwd | path join 'nushell' 'cache')
    }
    let repo_dir = ($cache_dir | path join 'nu_scripts')
    let completion_dir = ($repo_dir | path join 'custom-completions')

    if (which git | is-empty) {
        error make {
            msg: "`git` command is required for pj completion"
            help: "Install Git first, then run `pj completion` again."
        }
    }

    mkdir $cache_dir

    if $force {
        if ($repo_dir | path exists) {
            rm -rf $repo_dir
        }
    }

    if not ($repo_dir | path exists) {
        print "[pj completion] nu_scripts cache not found, cloning..."
        ^git clone $repo_url $repo_dir
    } else {
        if not (($repo_dir | path join '.git') | path exists) {
            print "[pj completion] existing cache is not a git repo, re-cloning..."
            rm -rf $repo_dir
            ^git clone $repo_url $repo_dir
        } else if $update {
            print "[pj completion] cache exists, updating..."
            ^git -C $repo_dir pull --ff-only
        }
    }

    if not ($completion_dir | path exists) {
        error make {
            msg: "nu_scripts cloned, but custom-completions directory is missing"
            help: $"Check repository content under ($repo_dir)."
        }
    }

    let required = (_pj_required_completion_files)
    let missing = ($required | where {|it| not ($it.file | path exists) })
    if not ($missing | is-empty) {
        print "[pj completion] warning: some required completion files are missing:"
        $missing | each {|it| print $"  - ($it.command): ($it.file)" }
    }

    print "[pj completion] ok"
    {
        cache_dir: $cache_dir
        repo_dir: $repo_dir
        completion_dir: $completion_dir
        commands: $pj_completion_commands
        missing_files: $missing
    }
}

export-env {
    $env.config = {
        completions: {
            quick: true
            partial: true
            algorithm: "fuzzy"
            case_sensitive: false
            external: {
                enable: true
                max_results: 100
            }
        }
    }

    if not ($pj_completion_registry_module | path exists) {
        mkdir $pj_cache_dir
        let content = ((_pj_completion_registry_lines) | str join "\n")
        $content | save -f $pj_completion_registry_module

        if (($env.PJ_COMPLETION_BOOTSTRAPPED? | default "0") != "1") {
            load-env { PJ_COMPLETION_BOOTSTRAPPED: "1" }
            print "[pj completion] generated cache registry, restarting Nushell..."
            exec nu
        }
    }
}

# Re-export completion externs from generated static registry.
export use $pj_completion_bootstrap_module *