package main

import (
	"crypto/rand"
	"fmt"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/studio-b12/gowebdav"
)

func (a *App) getSettings(c *gin.Context) {
	c.JSON(200, gin.H{
		"amApi": a.cfg.AMAPI, "downloadDir": a.cfg.DownloadDir,
		"webdavUrl": a.cfg.WebDAVURL, "webdavUser": a.cfg.WebDAVUser,
		"webdavPass": "", "hasWebdavPassword": a.cfg.WebDAVPass != "", "webdavPath": a.cfg.WebDAVPath,
		"quality": a.cfg.DefaultQuality, "webdavVersionPolicy": a.cfg.WebDAVVersionPolicy,
		"localFilePolicy": a.cfg.LocalFilePolicy,
	})
}

func (a *App) putSettings(c *gin.Context) {
	var v map[string]string
	if c.BindJSON(&v) != nil {
		c.Status(400)
		return
	}
	if x := v["amApi"]; x != "" {
		a.cfg.AMAPI = x
		a.saveSetting("am_api", x)
		a.am = &AMAPIClient{BaseURL: x, HTTP: a.httpClient}
	}
	if x := v["downloadDir"]; x != "" {
		a.cfg.DownloadDir = x
		a.saveSetting("download_dir", x)
	}
	if p := v["webdavVersionPolicy"]; p == "keep" || p == "replace_lower" {
		a.cfg.WebDAVVersionPolicy = p
	}
	if p := v["localFilePolicy"]; p == "keep" || p == "delete_after_upload" {
		a.cfg.LocalFilePolicy = p
	}
	if x, ok := v["webdavUrl"]; ok {
		a.cfg.WebDAVURL = x
	}
	if x, ok := v["webdavUser"]; ok {
		a.cfg.WebDAVUser = x
	}
	// The GET endpoint intentionally never returns the WebDAV password.
	// Therefore an empty webdavPass means "keep the existing password", not clear it.
	if x, ok := v["webdavPass"]; ok && x != "" {
		a.cfg.WebDAVPass = x
	}
	if x, ok := v["webdavPath"]; ok {
		a.cfg.WebDAVPath = strings.Trim(x, "/")
	}
	if x, ok := v["quality"]; ok && x != "" {
		a.cfg.DefaultQuality = x
	}
	for k, x := range map[string]string{
		"webdav_url": a.cfg.WebDAVURL, "webdav_user": a.cfg.WebDAVUser, "webdav_pass": a.cfg.WebDAVPass,
		"webdav_path": a.cfg.WebDAVPath, "quality": a.cfg.DefaultQuality,
		"webdav_version_policy": a.cfg.WebDAVVersionPolicy, "local_file_policy": a.cfg.LocalFilePolicy,
	} {
		a.saveSetting(k, x)
	}
	if a.cfg.WebDAVURL != "" {
		a.storage = NewWebDAVStorage(a.cfg)
	} else {
		a.storage = nil
	}
	// Credentials/config changes should repair already-downloaded local files
	// immediately instead of waiting for the periodic retry interval.
	go a.resyncPendingUploads()
	c.JSON(200, gin.H{"ok": true})
}

func (a *App) testWebDAV(c *gin.Context) {
	var v struct{ URL, User, Pass, Path string }
	if c.BindJSON(&v) != nil {
		c.Status(400)
		return
	}
	// An empty password means "use the saved password". The password is never
	// returned to the browser, so this also makes a fresh settings page test
	// the credential that is actually stored by the server.
	if v.URL == "" {
		v.URL = a.cfg.WebDAVURL
	}
	if v.User == "" {
		v.User = a.cfg.WebDAVUser
	}
	if v.Pass == "" {
		v.Pass = a.cfg.WebDAVPass
	}
	v.Path = strings.Trim(v.Path, "/")
	if v.Path == "" {
		v.Path = a.cfg.WebDAVPath
	}
	if v.URL == "" || v.User == "" || v.Pass == "" {
		c.JSON(400, gin.H{"ok": false, "error": "WebDAV URL、用户名或密码未配置"})
		return
	}
	client := gowebdav.NewClient(v.URL, v.User, v.Pass)
	client.SetTimeout(20 * time.Second)
	if err := client.Connect(); err != nil {
		c.JSON(502, gin.H{"ok": false, "error": "WebDAV authentication failed: " + err.Error()})
		return
	}
	if v.Path != "" {
		if err := client.MkdirAll(v.Path, 0755); err != nil {
			c.JSON(502, gin.H{"ok": false, "error": "WebDAV target path is not writable: " + err.Error()})
			return
		}
	}
	var token [12]byte
	if _, err := rand.Read(token[:]); err != nil {
		c.JSON(500, gin.H{"ok": false, "error": "failed to create test token"})
		return
	}
	testPath := strings.Trim(v.Path, "/") + "/.am-downloader-test-" + fmt.Sprintf("%x", token[:])
	if err := client.Write(testPath, []byte("ok"), 0644); err != nil {
		c.JSON(502, gin.H{"ok": false, "error": "WebDAV write test failed: " + err.Error()})
		return
	}
	_ = client.Remove(testPath)
	c.JSON(200, gin.H{"ok": true, "path": v.Path})
}