package app

import (
	"fmt"
	"strings"

	"douyu_go/internal/logger"
	"douyu_go/internal/types"
)

// ImportAccounts 将剪贴板中的账号行追加到账号文件。每行格式必须为
// 账号名----密码----Cookie，账号名不能与已有账号重复。
func (a *App) ImportAccounts(content string) types.AccountMutationResult {
	entries, err := parseAccountImport(content)
	if err != nil {
		return types.AccountMutationResult{Error: err.Error()}
	}

	a.accountsMu.Lock()
	defer a.accountsMu.Unlock()

	accountFile := a.scheduler.AccountFilePath()
	lines, err := parseAccountFile(accountFile)
	if err != nil {
		return types.AccountMutationResult{Error: "读取账号文件失败: " + err.Error()}
	}

	existingNames := make(map[string]struct{}, len(lines))
	for _, line := range lines {
		if line.Name != "" {
			existingNames[line.Name] = struct{}{}
		}
	}
	for _, entry := range entries {
		if _, exists := existingNames[entry.Name]; exists {
			return types.AccountMutationResult{Error: fmt.Sprintf("账号 %q 已存在", entry.Name)}
		}
		existingNames[entry.Name] = struct{}{}
		lines = append(lines, entry)
	}

	if err := a.saveAccountLines(accountFile, lines); err != nil {
		return types.AccountMutationResult{Error: err.Error()}
	}
	logger.LogEvent("账号", "success", "已从剪贴板导入 %d 个账号", len(entries))
	return types.AccountMutationResult{Success: true, Count: len(entries)}
}

// UpdateAccount 更新账号名或 Cookie。newCookie 留空时保留文件中的原 Cookie。
func (a *App) UpdateAccount(originalName, newName, newCookie string) types.AccountMutationResult {
	originalName = strings.TrimSpace(originalName)
	newName = strings.TrimSpace(newName)
	newCookie = strings.TrimSpace(newCookie)
	if originalName == "" || newName == "" {
		return types.AccountMutationResult{Error: "账号名不能为空"}
	}
	if invalidAccountField(newName) || strings.ContainsAny(newCookie, "\r\n") {
		return types.AccountMutationResult{Error: "账号名或 Cookie 包含无效字符"}
	}

	a.accountsMu.Lock()
	defer a.accountsMu.Unlock()

	accountFile := a.scheduler.AccountFilePath()
	lines, err := parseAccountFile(accountFile)
	if err != nil {
		return types.AccountMutationResult{Error: "读取账号文件失败: " + err.Error()}
	}

	targetIndex := -1
	nameCount := 0
	for i, line := range lines {
		if line.Name == originalName {
			targetIndex = i
			nameCount++
		}
		if line.Name == newName && newName != originalName {
			return types.AccountMutationResult{Error: fmt.Sprintf("账号 %q 已存在", newName)}
		}
	}
	if targetIndex < 0 {
		return types.AccountMutationResult{Error: "未找到要编辑的账号"}
	}
	if nameCount > 1 {
		return types.AccountMutationResult{Error: "账号名重复，请先删除重复账号后再编辑"}
	}

	parts := strings.SplitN(strings.TrimSpace(lines[targetIndex].Raw), "----", 3)
	if len(parts) != 3 {
		return types.AccountMutationResult{Error: "原账号格式不正确，无法保留密码段"}
	}
	oldCookie := strings.TrimSpace(parts[2])
	if newCookie == "" {
		newCookie = oldCookie
	}
	if newCookie == "" {
		return types.AccountMutationResult{Error: "Cookie 不能为空"}
	}
	lines[targetIndex] = accountLine{
		Raw:  newName + "----" + strings.TrimSpace(parts[1]) + "----" + newCookie,
		Name: newName,
	}

	if err := a.saveAccountLines(accountFile, lines); err != nil {
		return types.AccountMutationResult{Error: err.Error()}
	}
	logger.LogEvent("账号", "success", "账号已更新: %s", newName)
	return types.AccountMutationResult{Success: true, Count: 1}
}

// DeleteAccounts 从账号文件中删除指定账号，可一次删除多个账号。
func (a *App) DeleteAccounts(accountNames []string) types.AccountMutationResult {
	nameSet := make(map[string]struct{}, len(accountNames))
	for _, name := range accountNames {
		if trimmed := strings.TrimSpace(name); trimmed != "" {
			nameSet[trimmed] = struct{}{}
		}
	}
	if len(nameSet) == 0 {
		return types.AccountMutationResult{Error: "请选择要删除的账号"}
	}

	a.accountsMu.Lock()
	defer a.accountsMu.Unlock()

	accountFile := a.scheduler.AccountFilePath()
	lines, err := parseAccountFile(accountFile)
	if err != nil {
		return types.AccountMutationResult{Error: "读取账号文件失败: " + err.Error()}
	}
	kept := make([]accountLine, 0, len(lines))
	deleted := 0
	for _, line := range lines {
		if _, remove := nameSet[line.Name]; remove && !line.Comment {
			deleted++
			continue
		}
		kept = append(kept, line)
	}
	if deleted == 0 {
		return types.AccountMutationResult{Error: "未找到要删除的账号"}
	}

	if err := a.saveAccountLines(accountFile, kept); err != nil {
		return types.AccountMutationResult{Error: err.Error()}
	}
	logger.LogEvent("账号", "success", "已删除 %d 个账号", deleted)
	return types.AccountMutationResult{Success: true, Count: deleted}
}

func parseAccountImport(content string) ([]accountLine, error) {
	content = strings.ReplaceAll(content, "\r\n", "\n")
	content = strings.ReplaceAll(content, "\r", "\n")
	entries := make([]accountLine, 0)
	names := make(map[string]struct{})
	for index, raw := range strings.Split(content, "\n") {
		trimmed := strings.TrimSpace(raw)
		if trimmed == "" || strings.HasPrefix(trimmed, "#") {
			continue
		}
		parts := strings.SplitN(trimmed, "----", 3)
		if len(parts) != 3 {
			return nil, fmt.Errorf("第 %d 行格式不正确，应为 账号名----密码----Cookie", index+1)
		}
		name := strings.TrimSpace(parts[0])
		password := strings.TrimSpace(parts[1])
		cookie := strings.TrimSpace(parts[2])
		if name == "" || cookie == "" || invalidAccountField(name) || strings.ContainsAny(cookie, "\r\n") {
			return nil, fmt.Errorf("第 %d 行账号名或 Cookie 无效", index+1)
		}
		if _, exists := names[name]; exists {
			return nil, fmt.Errorf("剪贴板中账号 %q 重复", name)
		}
		names[name] = struct{}{}
		entries = append(entries, accountLine{Raw: name + "----" + password + "----" + cookie, Name: name})
	}
	if len(entries) == 0 {
		return nil, fmt.Errorf("未识别到可导入的账号")
	}
	return entries, nil
}

func invalidAccountField(value string) bool {
	return strings.ContainsAny(value, "\r\n") || strings.Contains(value, "----")
}

func (a *App) saveAccountLines(accountFile string, lines []accountLine) error {
	rawLines := make([]string, 0, len(lines))
	for _, line := range lines {
		rawLines = append(rawLines, line.Raw)
	}
	content := strings.Join(rawLines, "\r\n")
	if content != "" {
		content += "\r\n"
	}
	if _, err := writeFileWithBackup(accountFile, []byte(content)); err != nil {
		return fmt.Errorf("更新账号文件失败: %w", err)
	}
	a.scheduler.LoadAccounts()
	return nil
}