package main

// cloudbind.go 实现“项目身份与机器路径分离”的同步支撑：
// - machineID：本机稳定标识（哈希后缓存），云端行名 paths:<machineID>
// - machinePathsDoc / applyMachinePaths：只推拉本机的 {项目名:路径} 行
// - 云端有身份但本机没路径的项目进入待绑定清单，由 Dashboard 引导用户选目录绑定。

import (
	"crypto/sha256"
	"database/sql"
	"encoding/hex"
	"encoding/json"
	"errors"
	"os"
	"strings"
)

// machineID 返回本机稳定标识（原始 ID 哈希后取 16 个十六进制字符），缓存于 meta。
func (a *App) machineID() string {
	if a.store == nil {
		return "unknown"
	}
	if v := a.store.Meta("machine_id"); v != "" {
		return v
	}
	raw := rawMachineID()
	if raw == "" {
		raw, _ = os.Hostname()
	}
	if raw == "" {
		raw = "unknown-machine"
	}
	sum := sha256.Sum256([]byte(strings.ToLower(strings.TrimSpace(raw))))
	id := hex.EncodeToString(sum[:8])
	_ = a.store.SetMeta("machine_id", id)
	return id
}

// machinePathsDoc 生成本机路径文档 {项目名: 本机路径}（map 序列化按键排序，内容稳定可比较）。
func (a *App) machinePathsDoc() (string, error) {
	rows, e := a.store.db.Query(`SELECT name,path FROM projects ORDER BY name`)
	if e != nil {
		return "", e
	}
	defer rows.Close()
	m := map[string]string{}
	for rows.Next() {
		var name, path string
		if e := rows.Scan(&name, &path); e != nil {
			return "", e
		}
		if name != "" && path != "" {
			m[name] = path
		}
	}
	b, e := json.Marshal(m)
	return string(b), e
}

// applyMachinePaths 套用本机路径文档（换库/重装同机场景）：
// 本地没有该名项目且路径非空 → 直接入库；已有同名项目但路径不同 → 以远端为准更新。
func (a *App) applyMachinePaths(doc string) error {
	var m map[string]string
	if json.Unmarshal([]byte(doc), &m) != nil {
		return nil // 远端数据异常时忽略，不阻断同步
	}
	for name, path := range m {
		name, path = strings.TrimSpace(name), strings.TrimSpace(path)
		if name == "" || path == "" {
			continue
		}
		var pid int64
		var cur string
		e := a.store.db.QueryRow(`SELECT id,path FROM projects WHERE name=? LIMIT 1`, name).Scan(&pid, &cur)
		switch {
		case e == sql.ErrNoRows:
			now := nowRFC()
			// path 全局唯一：同路径已有别名项目时不强插（IGNORE）。
			if _, e := a.store.db.Exec(`INSERT OR IGNORE INTO projects(name,path,description,group_id,created_at,updated_at) VALUES(?,?,'',1,?,?)`,
				name, path, now, now); e != nil {
				return e
			}
		case e != nil:
			return e
		case cur != path:
			if _, e := a.store.db.Exec(`UPDATE projects SET path=?,updated_at=? WHERE id=?
				AND NOT EXISTS(SELECT 1 FROM projects p2 WHERE p2.path=? AND p2.id!=?)`,
				path, nowRFC(), pid, path, pid); e != nil {
				return e
			}
		}
	}
	return nil
}

// rebuildCloudPending 以最近一次云端身份文档为基准，重算仍未落地本机的项目清单（幂等）。
func (a *App) rebuildCloudPending(entries []projectDocEntry) {
	pending := []projectDocEntry{}
	for _, it := range entries {
		name := strings.TrimSpace(it.Name)
		if name == "" {
			continue
		}
		var pid int64
		if a.store.db.QueryRow(`SELECT id FROM projects WHERE name=? LIMIT 1`, name).Scan(&pid) == sql.ErrNoRows {
			it.Path = "" // 待绑定清单不携带其它机器的路径
			pending = append(pending, it)
		}
	}
	b, _ := json.Marshal(pending)
	_ = a.store.SetMeta("cloud_projects_pending", string(b))
}

// ListCloudPendingProjects 返回云端存在但本机尚未绑定路径的项目。
func (a *App) ListCloudPendingProjects() ([]projectDocEntry, error) {
	if e := a.ready(); e != nil {
		return nil, e
	}
	out := []projectDocEntry{}
	raw := a.store.Meta("cloud_projects_pending")
	if raw == "" {
		return out, nil
	}
	var list []projectDocEntry
	if json.Unmarshal([]byte(raw), &list) != nil {
		return out, nil
	}
	for _, it := range list {
		// 本地可能在同步间隙手动建了同名项目，再过滤一遍
		var pid int64
		if a.store.db.QueryRow(`SELECT id FROM projects WHERE name=? LIMIT 1`, it.Name).Scan(&pid) == sql.ErrNoRows {
			out = append(out, it)
		}
	}
	return out, nil
}

// BindCloudProject 把云端项目绑定到本机目录：带身份信息入库、移出待绑定清单，并触发一轮推送。
func (a *App) BindCloudProject(name, path string) (Project, error) {
	if e := a.ready(); e != nil {
		return Project{}, e
	}
	name, path = strings.TrimSpace(name), strings.TrimSpace(path)
	if name == "" {
		return Project{}, errors.New("NAME_REQUIRED")
	}
	if fi, e := os.Stat(path); e != nil || !fi.IsDir() {
		return Project{}, errors.New("DIR_NOT_FOUND")
	}
	entry := projectDocEntry{Name: name}
	if raw := a.store.Meta("cloud_projects_pending"); raw != "" {
		var list []projectDocEntry
		if json.Unmarshal([]byte(raw), &list) == nil {
			rest := make([]projectDocEntry, 0, len(list))
			for _, it := range list {
				if strings.TrimSpace(it.Name) == name {
					entry = it
					continue
				}
				rest = append(rest, it)
			}
			b, _ := json.Marshal(rest)
			_ = a.store.SetMeta("cloud_projects_pending", string(b))
		}
	}
	gid, e := a.ensureGroupID(entry.Group)
	if e != nil {
		return Project{}, e
	}
	var pid int64
	now := nowRFC()
	switch e := a.store.db.QueryRow(`SELECT id FROM projects WHERE path=?`, path).Scan(&pid); {
	case e == sql.ErrNoRows:
		r, e2 := a.store.db.Exec(`INSERT INTO projects(name,path,description,group_id,created_at,updated_at) VALUES(?,?,?,?,?,?)`,
			name, path, entry.Description, gid, now, now)
		if e2 != nil {
			return Project{}, e2
		}
		pid, _ = r.LastInsertId()
	case e != nil:
		return Project{}, e
	default:
		// 该目录已是本地项目：改名并入云端身份，避免出现两个同路径项目。
		if _, e := a.store.db.Exec(`UPDATE projects SET name=?,description=?,group_id=?,updated_at=? WHERE id=?`,
			name, entry.Description, gid, now, pid); e != nil {
			return Project{}, e
		}
	}
	if entry.Favorite {
		_, _ = a.store.db.Exec(`INSERT OR IGNORE INTO favorites(project_id,created_at) VALUES(?,?)`, pid, now)
	}
	a.store.Log("info", "同步", "云端项目已绑定本机目录", name+" → "+path)
	if a.syncUserID() > 0 {
		go a.syncOnce(true)
	}
	return a.store.GetProject(pid)
}