// Copyright (c) 2019-2023 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module main

import os
import os.cmdline
import rand
import v.help
import v.vmod

struct VpmSettings {
mut:
	is_help       bool
	is_verbose    bool
	server_urls   []string
	vmodules_path string
}

enum Source {
	git
	hg
	vpm
}

const (
	settings                  = &VpmSettings{}
	default_vpm_server_urls   = ['https://vpm.vlang.io', 'https://vpm.url4e.com']
	vpm_server_urls           = rand.shuffle_clone(default_vpm_server_urls) or { [] } // ensure that all queries are distributed fairly
	valid_vpm_commands        = ['help', 'search', 'install', 'update', 'upgrade', 'outdated',
		'list', 'remove', 'show']
	excluded_dirs             = ['cache', 'vlib']
	supported_vcs_systems     = ['git', 'hg']
	supported_vcs_folders     = ['.git', '.hg']
	supported_vcs_update_cmds = {
		'git': 'pull --recurse-submodules' // pulling with `--depth=1` leads to conflicts, when the upstream is more than 1 commit newer
		'hg':  'pull --update'
	}
	supported_vcs_install_cmds = {
		'git': 'clone --depth=1 --recursive --shallow-submodules'
		'hg':  'clone'
	}
	supported_vcs_outdated_steps = {
		'git': ['fetch', 'rev-parse @', 'rev-parse @{u}']
		'hg':  ['incoming']
	}
	supported_vcs_version_cmds = {
		'git': 'version'
		'hg':  'version'
	}
)

fn main() {
	init_settings()
	// This tool is intended to be launched by the v frontend,
	// which provides the path to V inside os.getenv('VEXE')
	// args are: vpm [options] SUBCOMMAND module names
	params := cmdline.only_non_options(os.args[1..])
	options := cmdline.only_options(os.args[1..])
	verbose_println('cli params: ${params}')
	if params.len < 1 {
		help.print_and_exit('vpm', exit_code: 5)
	}
	vpm_command := params[0]
	mut requested_modules := params[1..].clone()
	ensure_vmodules_dir_exist()
	// println('module names: ') println(requested_modules)
	match vpm_command {
		'help' {
			help.print_and_exit('vpm')
		}
		'search' {
			vpm_search(requested_modules)
		}
		'install' {
			vpm_install(requested_modules, options)
		}
		'update' {
			vpm_update(requested_modules)
		}
		'upgrade' {
			vpm_upgrade()
		}
		'outdated' {
			vpm_outdated()
		}
		'list' {
			vpm_list()
		}
		'remove' {
			vpm_remove(requested_modules)
		}
		'show' {
			vpm_show(requested_modules)
		}
		else {
			eprintln('Error: you tried to run "v ${vpm_command}"')
			eprintln('... but the v package management tool vpm only knows about these commands:')
			for validcmd in valid_vpm_commands {
				eprintln('    v ${validcmd}')
			}
			exit(3)
		}
	}
}

fn init_settings() {
	mut s := &VpmSettings(unsafe { nil })
	unsafe {
		s = settings
	}
	s.is_help = '-h' in os.args || '--help' in os.args || 'help' in os.args
	s.is_verbose = '-v' in os.args
	s.server_urls = cmdline.options(os.args, '-server-url')
	s.vmodules_path = os.vmodules_dir()
}

fn vpm_upgrade() {
	outdated := get_outdated() or { exit(1) }
	if outdated.len > 0 {
		vpm_update(outdated)
	} else {
		println('Modules are up to date.')
	}
}

fn vpm_outdated() {
	outdated := get_outdated() or { exit(1) }
	if outdated.len > 0 {
		eprintln('Outdated modules:')
		for m in outdated {
			eprintln('  ${m}')
		}
	} else {
		println('Modules are up to date.')
	}
}

fn vpm_list() {
	module_names := get_installed_modules()
	if module_names.len == 0 {
		eprintln('You have no modules installed.')
		exit(0)
	}
	for mod in module_names {
		println(mod)
	}
}

fn vpm_remove(module_names []string) {
	if settings.is_help {
		help.print_and_exit('remove')
	}
	if module_names.len == 0 {
		eprintln('´v remove´ requires *at least one* module name.')
		exit(2)
	}
	for name in module_names {
		final_module_path := valid_final_path_of_existing_module(name) or { continue }
		eprintln('Removing module "${name}" ...')
		verbose_println('removing folder ${final_module_path}')
		os.rmdir_all(final_module_path) or {
			verbose_println('error while removing "${final_module_path}": ${err.msg()}')
		}
		// delete author directory if it is empty
		author := name.split('.')[0]
		author_dir := os.real_path(os.join_path(settings.vmodules_path, author))
		if !os.exists(author_dir) {
			continue
		}
		if os.is_dir_empty(author_dir) {
			verbose_println('removing author folder ${author_dir}')
			os.rmdir(author_dir) or {
				verbose_println('error while removing "${author_dir}": ${err.msg()}')
			}
		}
	}
}

fn vpm_show(module_names []string) {
	installed_modules := get_installed_modules()
	for module_name in module_names {
		if module_name !in installed_modules {
			module_meta_info := get_module_meta_info(module_name) or { continue }
			print('
Name: ${module_meta_info.name}
Homepage: ${module_meta_info.url}
Downloads: ${module_meta_info.nr_downloads}
Installed: False
--------
')
			continue
		}
		path := os.join_path(os.vmodules_dir(), module_name.replace('.', os.path_separator))
		mod := vmod.from_file(os.join_path(path, 'v.mod')) or { continue }
		print('Name: ${mod.name}
Version: ${mod.version}
Description: ${mod.description}
Homepage: ${mod.repo_url}
Author: ${mod.author}
License: ${mod.license}
Location: ${path}
Requires: ${mod.dependencies.join(', ')}
--------
')
	}
}