package wecom

import (
	"bytes"
	"context"
	"io"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"

	"github.com/bytedance/sonic"

	"github.com/break/junhong_cmp_fiber/internal/infrastructure/integrationlog"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
)

const (
	submissionOutcomeSuccess = "success"
	submissionOutcomeFailed  = "failed"
	submissionOutcomeUnknown = "unknown"
)

// ApprovalSubmitRequest 是调用企微 applyevent 的安全请求。
type ApprovalSubmitRequest struct {
	InstanceID    uint
	ApplicationID uint
	TemplateID    string
	CreatorUserID string
	CorrelationID string
	Contents      []map[string]any
}

// ApprovalSubmitResult 描述企微是否明确创建审批单。
type ApprovalSubmitResult struct {
	Outcome     string
	SPNo        string
	Message     string
	SafeToRetry bool
}

// ApprovalSubmissionClient 调用企微 applyevent 并记录每次真实外呼。
type ApprovalSubmissionClient struct {
	tokens      DirectoryTokenProvider
	integration TokenIntegrationLog
	httpClient  *http.Client
	baseURL     string
	now         func() time.Time
}

// NewApprovalSubmissionClient 创建企业微信审批提交客户端。
func NewApprovalSubmissionClient(tokens DirectoryTokenProvider, integration TokenIntegrationLog, baseURL string, timeout time.Duration) *ApprovalSubmissionClient {
	if timeout <= 0 {
		timeout = constants.WeComDefaultHTTPTimeout
	}
	return &ApprovalSubmissionClient{
		tokens: tokens, integration: integration, httpClient: &http.Client{Timeout: timeout},
		baseURL: strings.TrimRight(baseURL, "/"), now: time.Now,
	}
}

// Submit 使用企微后台模板流程提交审批申请，绝不在结果未知时自动重发。
func (c *ApprovalSubmissionClient) Submit(ctx context.Context, input ApprovalSubmitRequest) (ApprovalSubmitResult, error) {
	if c == nil || c.tokens == nil || c.integration == nil || c.httpClient == nil {
		return ApprovalSubmitResult{Outcome: submissionOutcomeFailed, Message: "企业微信审批提交客户端未配置", SafeToRetry: true}, nil
	}
	token, err := c.tokens.GetAccessToken(ctx, input.ApplicationID)
	if err != nil {
		return ApprovalSubmitResult{Outcome: submissionOutcomeFailed, Message: "取得企业微信 access_token 失败", SafeToRetry: true}, err
	}
	request, err := c.newSubmitRequest(ctx, token, input)
	if err != nil {
		return ApprovalSubmitResult{Outcome: submissionOutcomeFailed, Message: "创建企业微信审批提交请求失败", SafeToRetry: true}, err
	}
	resourceID := strconv.FormatUint(uint64(input.InstanceID), 10)
	correlationID := strings.TrimSpace(input.CorrelationID)
	attempt, err := c.integration.Start(ctx, integrationlog.Attempt{
		Provider: constants.IntegrationProviderWeCom, Direction: constants.IntegrationDirectionOutbound,
		Operation: constants.IntegrationOperationWeComApprovalSubmit, ResourceType: constants.WeComApprovalInstanceResourceType,
		ResourceID: &resourceID, RequestSummary: map[string]any{
			"application_id": input.ApplicationID, "template_id": input.TemplateID,
			"creator_source_configured": input.CreatorUserID != "", "control_count": len(input.Contents),
		}, CorrelationID: optionalIntegrationString(correlationID),
	})
	if err != nil {
		return ApprovalSubmitResult{Outcome: submissionOutcomeFailed, Message: "写入企业微信审批提交日志失败", SafeToRetry: true}, err
	}
	startedAt := c.now()
	response, err := c.httpClient.Do(request)
	if err != nil {
		message := "企业微信审批提交请求结果未知"
		_, completeErr := c.integration.Complete(ctx, attempt.IntegrationID, integrationlog.Completion{
			Result: constants.IntegrationResultUnknown, ProviderCode: "request_unknown", ProviderMessage: message,
			ResponseSummary: map[string]any{"success": false}, DurationMS: c.now().Sub(startedAt).Milliseconds(),
			RecoveryStrategy: "按申请时间窗批量获取审批单号并核对详情，确认不存在后才允许受控重提",
		})
		if completeErr != nil {
			return ApprovalSubmitResult{Outcome: submissionOutcomeUnknown, Message: message}, completeErr
		}
		return ApprovalSubmitResult{Outcome: submissionOutcomeUnknown, Message: message}, nil
	}
	defer response.Body.Close()
	responseBody, readErr := io.ReadAll(io.LimitReader(response.Body, constants.WeComMaxResponseBodyBytes+1))
	if readErr != nil || int64(len(responseBody)) > constants.WeComMaxResponseBodyBytes {
		message := "企业微信审批提交响应无法确认"
		_, completeErr := c.integration.Complete(ctx, attempt.IntegrationID, integrationlog.Completion{
			Result: constants.IntegrationResultUnknown, HTTPStatus: response.StatusCode, ProviderCode: "invalid_response",
			ProviderMessage: message, ResponseSummary: map[string]any{"success": false},
			DurationMS:       c.now().Sub(startedAt).Milliseconds(),
			RecoveryStrategy: "按申请时间窗批量获取审批单号并核对详情，确认不存在后才允许受控重提",
		})
		if completeErr != nil {
			return ApprovalSubmitResult{Outcome: submissionOutcomeUnknown, Message: message}, completeErr
		}
		return ApprovalSubmitResult{Outcome: submissionOutcomeUnknown, Message: message}, nil
	}
	var result struct {
		ErrCode int64  `json:"errcode"`
		ErrMsg  string `json:"errmsg"`
		SPNo    string `json:"sp_no"`
	}
	if err := sonic.Unmarshal(responseBody, &result); err != nil {
		result.ErrMsg = "企业微信审批提交响应格式无效"
		result.ErrCode = int64(response.StatusCode)
	}
	if response.StatusCode < http.StatusOK || response.StatusCode >= http.StatusMultipleChoices || result.ErrCode != 0 || strings.TrimSpace(result.SPNo) == "" {
		providerCode := strconv.FormatInt(result.ErrCode, 10)
		if result.ErrCode == 0 {
			providerCode = strconv.Itoa(response.StatusCode)
		}
		message := strings.TrimSpace(result.ErrMsg)
		if message == "" {
			message = "企业微信明确拒绝审批提交"
		}
		_, completeErr := c.integration.Complete(ctx, attempt.IntegrationID, integrationlog.Completion{
			Result: constants.IntegrationResultFailed, HTTPStatus: response.StatusCode, ProviderCode: providerCode,
			ProviderMessage: message, ResponseSummary: map[string]any{"success": false, "errcode": result.ErrCode},
			DurationMS: c.now().Sub(startedAt).Milliseconds(),
		})
		if completeErr != nil {
			return ApprovalSubmitResult{Outcome: submissionOutcomeFailed, Message: message}, completeErr
		}
		return ApprovalSubmitResult{Outcome: submissionOutcomeFailed, Message: message}, nil
	}
	_, err = c.integration.Complete(ctx, attempt.IntegrationID, integrationlog.Completion{
		Result: constants.IntegrationResultSuccess, HTTPStatus: response.StatusCode,
		ProviderCode: strconv.FormatInt(result.ErrCode, 10), ProviderMessage: result.ErrMsg,
		ResponseSummary: map[string]any{"success": true, "sp_no": strings.TrimSpace(result.SPNo)},
		DurationMS:      c.now().Sub(startedAt).Milliseconds(), StateChanged: true,
	})
	return ApprovalSubmitResult{Outcome: submissionOutcomeSuccess, SPNo: strings.TrimSpace(result.SPNo)}, err
}

// newSubmitRequest 只组装本次企微审批请求，调用前不会产生外部副作用。
func (c *ApprovalSubmissionClient) newSubmitRequest(ctx context.Context, token string, input ApprovalSubmitRequest) (*http.Request, error) {
	payload := map[string]any{
		"creator_userid":        input.CreatorUserID,
		"template_id":           input.TemplateID,
		"use_template_approver": 1,
		"apply_data":            map[string]any{"contents": input.Contents},
		"summary_list":          []map[string]any{{"summary_info": []map[string]string{{"text": "业务审批申请", "lang": "zh_CN"}}}},
	}
	body, err := sonic.Marshal(payload)
	if err != nil {
		return nil, errors.Wrap(errors.CodeInternalError, err, "编码企业微信审批提交请求失败")
	}
	endpoint, err := url.Parse(c.baseURL + "/cgi-bin/oa/applyevent")
	if err != nil || endpoint.Scheme == "" || endpoint.Host == "" {
		return nil, errors.New(errors.CodeWeComCredentialInvalid, "企业微信 API 地址配置无效")
	}
	query := endpoint.Query()
	query.Set("access_token", token)
	endpoint.RawQuery = query.Encode()
	request, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint.String(), bytes.NewReader(body))
	if err != nil {
		return nil, errors.Wrap(errors.CodeInternalError, err, "创建企业微信审批提交请求失败")
	}
	request.Header.Set("Content-Type", "application/json")
	return request, nil
}

func optionalIntegrationString(value string) *string {
	if value == "" {
		return nil
	}
	return &value
}