namespace SimpleAdmin.Application;

/// <summary>
/// 合同模板主档案；具体 DOCX 文件、变量与适用范围均挂在此档案下。
/// </summary>
public class OnboardingContractTemplateService : DbRepository<ObContractTemplate>, IOnboardingContractTemplateService
{
    private readonly IFileService _fileService;

    public OnboardingContractTemplateService(IFileService fileService)
    {
        _fileService = fileService;
    }

    /// <summary>
    /// 分页查询合同模板主档案。
    /// </summary>
    public async Task<SqlSugarPagedList<ObContractTemplate>> Page(OnboardingContractTemplatePageInput input)
    {
        return await Context.Queryable<ObContractTemplate>()
            .WhereIF(
                !string.IsNullOrWhiteSpace(input.TemplateName),
                it => it.TemplateName.Contains(input.TemplateName) || it.TemplateCode.Contains(input.TemplateName))
            .WhereIF(!string.IsNullOrWhiteSpace(input.ContractType), it => it.ContractType == input.ContractType)
            .WhereIF(!string.IsNullOrWhiteSpace(input.Status), it => it.Status == input.Status)
            .OrderByIF(!string.IsNullOrWhiteSpace(input.SortField), $"{input.SortField} {input.SortOrder}")
            .OrderBy(it => it.TemplateName)
            .ToPagedListAsync(input.PageNum, input.PageSize);
    }

    /// <summary>
    /// 查询合同模板详情。
    /// </summary>
    public async Task<ObContractTemplate> Detail(BaseIdInput input)
    {
        return await GetByIdAsync(input.Id) ?? throw Oops.Bah("合同模板不存在");
    }

    /// <summary>
    /// 新增合同模板主档案。
    /// </summary>
    public async Task Add(OnboardingContractTemplateAddInput input)
    {
        await EnsureCodeUnique(input.TemplateCode, 0);
        await InsertAsync(input.Adapt<ObContractTemplate>());
    }

    /// <summary>
    /// 编辑合同模板主档案。
    /// </summary>
    public async Task Edit(OnboardingContractTemplateEditInput input)
    {
        await Detail(new BaseIdInput { Id = input.Id });
        await EnsureCodeUnique(input.TemplateCode, input.Id);
        await UpdateAsync(input.Adapt<ObContractTemplate>());
    }

    /// <summary>
    /// 删除未被入职模板或任务合同引用的模板（级联删除未使用的版本和变量）。
    /// </summary>
    public async Task Delete(BaseIdListInput input)
    {
        if (input.Ids.Count == 0)
            return;

        var hasOnboardingTemplates = await Context.Queryable<ObOnboardingTemplateContract>()
            .AnyAsync(it => input.Ids.Contains(it.ContractTemplateId));
        if (hasOnboardingTemplates)
            throw Oops.Bah("模板已被入职模板引用，不能删除，请先在入职模板中移除关联");

        var hasContracts = await Context.Queryable<ObTaskContract>()
            .AnyAsync(it => input.Ids.Contains(it.TemplateId));
        if (hasContracts)
            throw Oops.Bah("模板已生成入职任务合同，不能删除，可改为停用");

        var versionIds = await Context.Queryable<ObContractTemplateVersion>()
            .Where(it => input.Ids.Contains(it.TemplateId))
            .Select(it => it.Id)
            .ToListAsync();

        await Context.Ado.BeginTranAsync();
        try
        {
            if (versionIds.Count > 0)
            {
                await Context.Deleteable<ObTemplateVariable>()
                    .Where(it => versionIds.Contains(it.TemplateVersionId))
                    .ExecuteCommandAsync();
                await Context.Deleteable<ObContractTemplateVersion>()
                    .In(versionIds)
                    .ExecuteCommandAsync();
            }

            await Context.Deleteable<ObContractScope>()
                .Where(it => input.Ids.Contains(it.TemplateId))
                .ExecuteCommandAsync();

            await DeleteByIdsAsync(input.Ids.Cast<object>().ToArray());
            await Context.Ado.CommitTranAsync();
        }
        catch
        {
            await Context.Ado.RollbackTranAsync();
            throw;
        }
    }

    /// <summary>
    /// 删除未被入职模板或任务使用的合同版本。
    /// </summary>
    public async Task DeleteVersion(BaseIdInput input)
    {
        var version = await Context.Queryable<ObContractTemplateVersion>().InSingleAsync(input.Id)
            ?? throw Oops.Bah("合同版本不存在");

        var isUsedInOnboardingTemplate = await Context.Queryable<ObOnboardingTemplateContract>()
            .AnyAsync(it => it.ContractTemplateVersionId == version.Id);
        if (isUsedInOnboardingTemplate)
            throw Oops.Bah("该版本已被入职模板引用，不能删除，请先在入职模板中移除关联");

        var isUsedInTask = await Context.Queryable<ObTaskContract>()
            .AnyAsync(it => it.TemplateVersionId == version.Id);
        if (isUsedInTask)
            throw Oops.Bah("该版本已用于实际入职任务，不能删除，可改为停用");

        await Context.Ado.BeginTranAsync();
        try
        {
            await Context.Deleteable<ObTemplateVariable>()
                .Where(it => it.TemplateVersionId == version.Id)
                .ExecuteCommandAsync();
            await Context.Deleteable<ObContractScope>()
                .Where(it => it.TemplateVersionId == version.Id)
                .ExecuteCommandAsync();
            await Context.Deleteable<ObContractTemplateVersion>()
                .In(version.Id)
                .ExecuteCommandAsync();
            await Context.Ado.CommitTranAsync();
        }
        catch
        {
            await Context.Ado.RollbackTranAsync();
            throw;
        }
    }

    /// <summary>
    /// 分页查询指定合同模板的版本。
    /// </summary>
    public async Task<SqlSugarPagedList<ObContractTemplateVersion>> VersionPage(OnboardingContractVersionPageInput input)
    {
        return await Context.Queryable<ObContractTemplateVersion>()
            .Where(it => it.TemplateId == input.TemplateId)
            .WhereIF(!string.IsNullOrWhiteSpace(input.VersionStatus), it => it.VersionStatus == input.VersionStatus)
            .OrderByDescending(it => it.CreateTime)
            .ToPagedListAsync(input.PageNum, input.PageSize);
    }

    /// <summary>
    /// 新增合同模板 DOCX 版本。
    /// </summary>
    public async Task AddVersion(OnboardingContractVersionAddInput input)
    {
        await Detail(new BaseIdInput { Id = input.TemplateId });
        var file = await Context.Queryable<SysFile>().InSingleAsync(input.SourceDocxFileId)
            ?? throw Oops.Bah("DOCX 源文件不存在");
        if (!string.Equals(file.Suffix, "docx", StringComparison.OrdinalIgnoreCase))
            throw Oops.Bah("合同模板仅支持 DOCX 文件");

        var versionExists = await Context.Queryable<ObContractTemplateVersion>()
            .AnyAsync(item => item.TemplateId == input.TemplateId && item.VersionNo == input.VersionNo);
        if (versionExists)
            throw Oops.Bah("该模板版本号已存在");

        var sourceResult = await _fileService.Download(new BaseIdInput { Id = file.Id })
            ?? throw Oops.Bah("无法读取 DOCX 源文件");
        await using var sourceStream = sourceResult.FileStream;
        using var sourceBytes = new MemoryStream();
        await sourceStream.CopyToAsync(sourceBytes);
        var bytes = sourceBytes.ToArray();
        var variableCodes = DocxTemplateProcessor.ExtractVariableCodes(bytes);

        // 严格比对变量字典库，防止手误和非法占位符
        var dictList = await Context.Queryable<ObVariableDefinition>().ToListAsync();
        var dictMap = dictList.ToDictionary(it => it.VariableCode, it => it, StringComparer.OrdinalIgnoreCase);
        var undefinedCodes = variableCodes.Where(code => !dictMap.ContainsKey(code)).ToList();
        if (undefinedCodes.Count > 0)
        {
            throw Oops.Bah($"DOCX 模板包含未在字典库中注册的占位符：{string.Join("，", undefinedCodes)}。请检查拼写或先在【变量字典】中添加该变量。");
        }

        var versionId = global::SimpleAdmin.Core.Utils.CommonUtils.GetSingleId();
        var version = input.Adapt<ObContractTemplateVersion>();
        version.Id = versionId;
        version.VersionStatus = ContractTemplateVersionStatus.Draft;
        version.FileHash = string.IsNullOrWhiteSpace(input.FileHash)
            ? Convert.ToHexString(global::System.Security.Cryptography.SHA256.HashData(bytes))
            : input.FileHash;

        var variables = variableCodes.Select((code, index) =>
        {
            var def = dictMap.TryGetValue(code, out var d) ? d : null;
            return BuildDetectedVariable(versionId, code, def, index);
        }).ToList();

        await Context.Ado.BeginTranAsync();
        try
        {
            await Context.Insertable(version).ExecuteCommandAsync();
            if (variables.Count > 0)
                await Context.Insertable(variables).ExecuteCommandAsync();
            await Context.Ado.CommitTranAsync();
        }
        catch
        {
            await Context.Ado.RollbackTranAsync();
            throw;
        }
    }

    /// <summary>
    /// 启用或停用合同模板版本。
    /// </summary>
    public async Task SetVersionStatus(OnboardingContractVersionStatusInput input)
    {
        if (input.VersionStatus != ContractTemplateVersionStatus.Enabled
            && input.VersionStatus != ContractTemplateVersionStatus.Disabled)
        {
            throw Oops.Bah("版本状态仅支持启用或停用");
        }

        var version = await Context.Queryable<ObContractTemplateVersion>().InSingleAsync(input.Id)
            ?? throw Oops.Bah("模板版本不存在");

        if (input.VersionStatus == ContractTemplateVersionStatus.Enabled)
        {
            var hasUnresolvedVariables = await Context.Queryable<ObTemplateVariable>()
                .AnyAsync(item => item.TemplateVersionId == input.Id
                                  && item.VariableType == ContractVariableType.Unresolved);
            if (hasUnresolvedVariables)
                throw Oops.Bah("仍有未识别来源的合同变量，请逐项确认后再启用");
        }

        version.VersionStatus = input.VersionStatus;
        await Context.Updateable(version).ExecuteCommandAsync();
    }

    /// <summary>
    /// 分页查询指定模板版本的变量定义。
    /// </summary>
    public async Task<SqlSugarPagedList<ObTemplateVariable>> VariablePage(OnboardingTemplateVariablePageInput input)
    {
        return await Context.Queryable<ObTemplateVariable>()
            .Where(it => it.TemplateVersionId == input.TemplateVersionId)
            .OrderBy(it => it.SortCode)
            .OrderBy(it => it.VariableCode)
            .ToPagedListAsync(input.PageNum, input.PageSize);
    }
    /// <summary>
    /// 编辑模板版本中自动识别出的变量，不允许修改 DOCX 占位符编码。
    /// </summary>
    public async Task EditVariable(OnboardingTemplateVariableEditInput input)
    {
        var variable = await Context.Queryable<ObTemplateVariable>().InSingleAsync(input.Id)
            ?? throw Oops.Bah("模板变量不存在");
        if (variable.TemplateVersionId != input.TemplateVersionId)
            throw Oops.Bah("不允许变更变量所属版本");
        if (!string.Equals(variable.VariableCode, input.VariableCode, StringComparison.Ordinal))
            throw Oops.Bah("DOCX 占位符编码由系统识别，不能修改");

        var isUsedInTask = await Context.Queryable<ObTaskContract>()
            .AnyAsync(it => it.TemplateVersionId == input.TemplateVersionId);
        if (isUsedInTask)
            throw Oops.Bah("该版本已生成实际入职任务合同，变量配置已锁定");

        var entity = input.Adapt<ObTemplateVariable>();
        entity.VariableCode = variable.VariableCode;
        await Context.Updateable(entity).ExecuteCommandAsync();
    }

    private static ObTemplateVariable BuildDetectedVariable(long versionId, string code, ObVariableDefinition def, int index)
    {
        var separatorIndex = code.IndexOf('.');
        var prefix = separatorIndex > 0 ? code[..separatorIndex].ToLowerInvariant() : string.Empty;
        var sourceField = separatorIndex > 0 ? code[(separatorIndex + 1)..] : code;
        var variableType = prefix switch
        {
            "employee" => ContractVariableType.Employee,
            "company" => ContractVariableType.Company,
            "hr" => ContractVariableType.Contract,
            "system" => ContractVariableType.System,
            _ => ContractVariableType.Unresolved
        };

        var varName = def != null && !string.IsNullOrWhiteSpace(def.VariableName) ? def.VariableName : sourceField;
        var dataType = def != null && !string.IsNullOrWhiteSpace(def.DataType) ? def.DataType : InferDataType(sourceField);

        return new ObTemplateVariable
        {
            Id = global::SimpleAdmin.Core.Utils.CommonUtils.GetSingleId(),
            TemplateVersionId = versionId,
            VariableCode = code,
            VariableName = varName,
            VariableType = variableType,
            DataType = dataType,
            EmployeeField = variableType is ContractVariableType.Employee or ContractVariableType.Company
                ? sourceField
                : null,
            Required = def?.Required ?? true,
            HrEditable = variableType == ContractVariableType.Contract,
            SortCode = (index + 1) * 10,
            Remark = def?.Remark
        };
    }

    private static string InferDataType(string sourceField)
    {
        var normalized = sourceField.ToLowerInvariant();
        if (normalized.Contains("date") || normalized.EndsWith("at"))
            return "date";
        if (normalized.Contains("salary")
            || normalized.Contains("amount")
            || normalized.Contains("wage")
            || normalized.Contains("copies"))
        {
            return "decimal";
        }

        return "string";
    }

    private async Task EnsureCodeUnique(string code, long id)
    {
        var exists = await Context.Queryable<ObContractTemplate>()
            .AnyAsync(it => it.TemplateCode == code && it.Id != id);
        if (exists)
            throw Oops.Bah("模板编码已存在");
    }
}