// Copyright 2026 Alibaba Group
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Package config provides shared constants used across multiple internal
// packages. Only cross-cutting values belong here; package-private
// constants should remain in their own package.
package config

import (
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"time"
)

// ── File permissions ────────────────────────────────────────────────────
// These are used consistently by auth, security, and cache packages to
// protect sensitive data on disk.

const (
	// DirPerm is the permission mode for directories that hold sensitive
	// data (token store, cache, lock files). Owner-only rwx.
	DirPerm os.FileMode = 0o700

	// FilePerm is the permission mode for sensitive files (encrypted
	// tokens, cache entries, lock files). Owner-only rw.
	FilePerm os.FileMode = 0o600
)

// ── HTTP timeouts ───────────────────────────────────────────────────────
// Shared across transport, market, auth, and device-flow packages.

const (
	// HTTPTimeout is the default timeout for outgoing HTTP requests
	// (market registry, MCP JSON-RPC, device flow).
	HTTPTimeout = 30 * time.Second

	// OAuthTimeout is the timeout for OAuth token exchange/refresh
	// requests, which are latency-sensitive and should fail fast.
	OAuthTimeout = 15 * time.Second

	// DiscoveryTimeout bounds the time spent on live registry + runtime
	// discovery before falling back to cache.
	DiscoveryTimeout = 10 * time.Second

	// LockTimeout is how long to wait when acquiring a cross-process
	// file lock for token operations.
	LockTimeout = 10 * time.Second
)

// ── Response limits ─────────────────────────────────────────────────────

const (
	// MaxResponseBodySize limits the amount of data read from a single
	// HTTP response to prevent memory exhaustion from malicious servers.
	MaxResponseBodySize = 10 * 1024 * 1024 // 10 MB
)

// ── Cache ───────────────────────────────────────────────────────────────

const (
	// DefaultPartition is the cache partition used when no tenant/org
	// context is available.
	DefaultPartition = "default/default"
)

// IsOpenEdition reports whether an edition name maps to the open-source core.
//
// This helper takes the edition name as a parameter instead of calling
// edition.Get() so that pkg/config remains a leaf dependency — importable
// from internal/cli, internal/app, internal/cache, etc. without risking
// import cycles.
func IsOpenEdition(name string) bool {
	name = strings.TrimSpace(name)
	return name == "" || name == "open"
}

// EditionPartition returns the cache partition for a given edition name.
// The open-source core (name == "" or "open") uses DefaultPartition; every
// other edition gets its own namespace to prevent cross-edition data
// leakage in the disk cache.
func EditionPartition(name string) string {
	name = strings.TrimSpace(name)
	if IsOpenEdition(name) {
		return DefaultPartition
	}
	return name + "/default"
}

// EditionFileName returns the edition-partitioned file name for base+ext.
func EditionFileName(name, base, ext string) string {
	name = strings.TrimSpace(name)
	if IsOpenEdition(name) {
		return base + ext
	}
	return base + "-" + name + ext
}

// ── Auth flow timeouts ──────────────────────────────────────────────────

const (
	// ManualTokenExpiry is the default lifetime for manually imported tokens.
	ManualTokenExpiry = 24 * time.Hour

	// DeviceFlowTimeout is the maximum wait time for device-flow authorization.
	DeviceFlowTimeout = 16 * time.Minute

	// OAuthFlowTimeout is the maximum wait time for browser-based OAuth.
	OAuthFlowTimeout = 6 * time.Minute

	// DefaultAccessTokenExpiry is the default access token lifetime in seconds
	// when the server does not return an explicit expires_in value.
	DefaultAccessTokenExpiry = 7200

	// DefaultRefreshTokenLifetime is the default refresh token lifetime.
	DefaultRefreshTokenLifetime = 30 * 24 * time.Hour
)

// ── Market ──────────────────────────────────────────────────────────────

const (
	// DefaultFetchServersLimit is the maximum number of servers to fetch
	// from the market registry in a single request.
	DefaultFetchServersLimit = 200
)

// ── Upload limits ───────────────────────────────────────────────────────

const (
	// MaxUploadFileSize is the maximum file size for attachment uploads.
	MaxUploadFileSize int64 = 100 * 1024 * 1024 // 100 MB
)

// ── Plugin system ──────────────────────────────────────────────────────

const (
	// PluginUserDir is the subdirectory under ~/.dws/plugins/ where all
	// third-party plugins are installed. Every plugin — whether authored
	// by the DingTalk team or anyone else — lives here with equal status.
	PluginUserDir = "user"

	// PluginDataDir is the subdirectory under ~/.dws/plugins/ for
	// plugin persistent data that survives across version updates.
	PluginDataDir = "data"

	// PluginHookTimeout is the default timeout for plugin hook commands.
	PluginHookTimeout = 30 * time.Second
)

// ── Platform URLs ────────────────────────────────────────────────────────────
// Shared across auth, errors, and device-flow packages.

const (
	// DefaultMCPBaseURL is the DingTalk MCP base URL.
	// Override at runtime via ~/.dws/mcp_url file.
	DefaultMCPBaseURL = "https://mcp.dingtalk.com"

	// ManagedMCPURLRegionFileName records an MCP URL written automatically by
	// login region selection, so a later region change does not delete a user's
	// explicit MCP override.
	ManagedMCPURLRegionFileName = "mcp_url.login_region"

	// DefaultTerminalBaseURL is the DingTalk developer platform base URL.
	// Override at runtime via ~/.dws/terminal_url file.
	DefaultTerminalBaseURL = "https://open-dev.dingtalk.com"

	// InternationalTerminalBaseURL is the DingTalk international developer
	// platform base URL.
	InternationalTerminalBaseURL = "https://open-dev.dingtalk.io"

	// DeveloperSettingsPath is the path to the organization developer
	// settings page (CLI access management).
	DeveloperSettingsPath = "/fe/old#/developerSettings"
)

// DefaultConfigDir returns the default DWS configuration directory.
// Priority: DWS_CONFIG_DIR env var > ~/.dws
func DefaultConfigDir() string {
	if envDir := os.Getenv("DWS_CONFIG_DIR"); envDir != "" {
		return envDir
	}
	homeDir, err := os.UserHomeDir()
	if err != nil {
		return ".dws"
	}
	return filepath.Join(homeDir, ".dws")
}

// GetMCPBaseURL returns the MCP base URL with priority:
//  1. ~/.dws/mcp_url file content (for custom environment)
//  2. Default value (https://mcp.dingtalk.com)
func GetMCPBaseURL() string {
	mcpURLPath := filepath.Join(DefaultConfigDir(), "mcp_url")
	if data, err := os.ReadFile(mcpURLPath); err == nil {
		if u := strings.TrimSpace(string(data)); u != "" {
			return u
		}
	}
	return DefaultMCPBaseURL
}

// GetTerminalBaseURL returns the terminal base URL with priority:
//  1. ~/.dws/terminal_url file content (for custom environments)
//  2. International terminal when the configured MCP endpoint uses .io
//  3. Default value (https://open-dev.dingtalk.com)
func GetTerminalBaseURL() string {
	terminalURLPath := filepath.Join(DefaultConfigDir(), "terminal_url")
	if data, err := os.ReadFile(terminalURLPath); err == nil {
		if u := strings.TrimSpace(string(data)); u != "" {
			return u
		}
	}
	if parsed, err := url.Parse(GetMCPBaseURL()); err == nil {
		host := strings.ToLower(parsed.Hostname())
		if host == "dingtalk.io" || strings.HasSuffix(host, ".dingtalk.io") {
			return InternationalTerminalBaseURL
		}
	}
	return DefaultTerminalBaseURL
}

// GetDeveloperSettingsURL returns the full URL to the organization developer
// settings page, derived from the terminal base URL.
func GetDeveloperSettingsURL() string {
	return GetTerminalBaseURL() + DeveloperSettingsPath
}