package app

import (
	"context"
	"net/http"
	"strconv"
	"strings"

	"sub2api-cn-relay-manager/internal/batch"
	"sub2api-cn-relay-manager/internal/store/sqlite"
)

type BatchImportEntryRequest struct {
	BaseURL         string   `json:"base_url"`
	APIKey          string   `json:"api_key"`
	RequestedModels []string `json:"requested_models"`
}

type CreateBatchImportRunRequest struct {
	HostID                string                    `json:"host_id,omitempty"`
	Mode                  string                    `json:"mode"`
	AccessMode            string                    `json:"access_mode"`
	ConfirmWaitTimeoutSec int                       `json:"confirm_wait_timeout_sec,omitempty"`
	SubscriptionUsers     []string                  `json:"subscription_users,omitempty"`
	SubscriptionDays      int                       `json:"subscription_days,omitempty"`
	ProbeAPIKey           string                    `json:"probe_api_key,omitempty"`
	Entries               []BatchImportEntryRequest `json:"entries"`
}

type BatchImportRunCreateResponse struct {
	RunID         string `json:"run_id"`
	State         string `json:"state"`
	ResultPage    string `json:"result_page"`
	TotalItems    int    `json:"total_items"`
	ActiveItems   int    `json:"active_items"`
	DegradedItems int    `json:"degraded_items"`
	BrokenItems   int    `json:"broken_items"`
	WarningItems  int    `json:"warning_items"`
}

type ListBatchImportRunsRequest struct {
	State      string
	AccessMode string
	Query      string
	Cursor     string
	Limit      int
}

type ListBatchImportRunsResponse struct {
	Runs       []batch.RunSummaryProjection `json:"runs"`
	NextCursor *string                      `json:"next_cursor"`
}

type ListBatchImportRunItemsRequest struct {
	RunID               string
	CurrentStage        string
	ConfirmationStatus  string
	AccessStatus        string
	HasWarning          *bool
	ProviderID          string
	MatchedAccountState string
	AccountResolution   string
	Query               string
	Cursor              string
	Limit               int
}

type ListBatchImportRunItemsResponse struct {
	Items      []batch.ItemSummaryProjection `json:"items"`
	NextCursor *string                       `json:"next_cursor"`
}

type GetBatchImportRunItemRequest struct {
	RunID  string
	ItemID string
}

func handleCreateBatchImportRun(w http.ResponseWriter, r *http.Request, fn func(context.Context, CreateBatchImportRunRequest) (BatchImportRunCreateResponse, error)) {
	if fn == nil {
		writeHTTPError(w, &httpError{StatusCode: http.StatusInternalServerError, Code: "server_misconfigured", Message: "create-batch-import-run action is not configured"})
		return
	}
	var req CreateBatchImportRunRequest
	if err := decodeJSON(r, &req); err != nil {
		writeHTTPError(w, err)
		return
	}
	if err := validateCreateBatchImportRunRequest(req); err != nil {
		writeHTTPError(w, err)
		return
	}
	result, err := fn(r.Context(), req)
	if err != nil {
		writeHTTPError(w, classifyError(err))
		return
	}
	writeJSON(w, http.StatusOK, result)
}

func handleListBatchImportRuns(w http.ResponseWriter, r *http.Request, fn func(context.Context, ListBatchImportRunsRequest) (ListBatchImportRunsResponse, error)) {
	if fn == nil {
		writeHTTPError(w, &httpError{StatusCode: http.StatusInternalServerError, Code: "server_misconfigured", Message: "list-batch-import-runs action is not configured"})
		return
	}
	result, err := fn(r.Context(), ListBatchImportRunsRequest{
		State:      strings.TrimSpace(r.URL.Query().Get("state")),
		AccessMode: strings.TrimSpace(r.URL.Query().Get("access_mode")),
		Query:      strings.TrimSpace(r.URL.Query().Get("q")),
		Cursor:     strings.TrimSpace(r.URL.Query().Get("cursor")),
		Limit:      parsePositiveInt(r.URL.Query().Get("limit")),
	})
	if err != nil {
		writeHTTPError(w, classifyError(err))
		return
	}
	if result.Runs == nil {
		result.Runs = []batch.RunSummaryProjection{}
	}
	writeJSON(w, http.StatusOK, result)
}

func buildCreateBatchImportRunAction(sqliteDSN string) func(context.Context, CreateBatchImportRunRequest) (BatchImportRunCreateResponse, error) {
	return func(ctx context.Context, req CreateBatchImportRunRequest) (BatchImportRunCreateResponse, error) {
		store, err := sqlite.Open(ctx, sqliteDSN)
		if err != nil {
			return BatchImportRunCreateResponse{}, err
		}
		defer store.Close()

		hostRow, client, err := resolveManagedHost(ctx, store, req.HostID, "", CreateHostAuth{})
		if err != nil {
			return BatchImportRunCreateResponse{}, err
		}
		runner := batchImportRuntimeRunner{
			store:      store,
			hostRow:    hostRow,
			hostClient: client,
			request:    req,
		}
		return runner.execute(ctx)
	}
}

func buildListBatchImportRunsAction(sqliteDSN string) func(context.Context, ListBatchImportRunsRequest) (ListBatchImportRunsResponse, error) {
	return func(ctx context.Context, req ListBatchImportRunsRequest) (ListBatchImportRunsResponse, error) {
		store, err := sqlite.Open(ctx, sqliteDSN)
		if err != nil {
			return ListBatchImportRunsResponse{}, err
		}
		defer store.Close()

		runs, err := store.ImportRuns().List(ctx, 1000)
		if err != nil {
			return ListBatchImportRunsResponse{}, err
		}

		limit := defaultPositiveInt(req.Limit, 50)
		result := make([]batch.RunSummaryProjection, 0, limit)
		nextCursor := (*string)(nil)
		started := strings.TrimSpace(req.Cursor) == ""
		for _, run := range runs {
			if !started {
				if run.RunID == strings.TrimSpace(req.Cursor) {
					started = true
				}
				continue
			}
			if req.State != "" && run.State != req.State {
				continue
			}
			if req.AccessMode != "" && run.AccessMode != req.AccessMode {
				continue
			}
			if req.Query != "" {
				query := strings.ToLower(req.Query)
				if !strings.Contains(strings.ToLower(run.RunID), query) {
					items, err := store.ImportRunItems().ListByRunID(ctx, run.RunID)
					if err != nil {
						return ListBatchImportRunsResponse{}, err
					}
					matched := false
					for _, item := range items {
						if strings.Contains(strings.ToLower(item.ProviderID), query) || strings.Contains(strings.ToLower(item.BaseURL), query) {
							matched = true
							break
						}
					}
					if !matched {
						continue
					}
				}
			}
			if len(result) >= limit {
				cursor := run.RunID
				nextCursor = &cursor
				break
			}
			result = append(result, batch.ProjectRunSummary(run))
		}
		return ListBatchImportRunsResponse{Runs: result, NextCursor: nextCursor}, nil
	}
}

func validateCreateBatchImportRunRequest(req CreateBatchImportRunRequest) *httpError {
	if strings.TrimSpace(req.HostID) == "" {
		return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "host_id is required"}
	}
	if strings.TrimSpace(req.Mode) == "" {
		return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "mode is required"}
	}
	if strings.TrimSpace(req.AccessMode) == "" {
		return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "access_mode is required"}
	}
	if len(req.Entries) == 0 {
		return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "entries is required"}
	}
	switch strings.TrimSpace(req.AccessMode) {
	case "subscription":
		if len(req.SubscriptionUsers) == 0 {
			return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "subscription_users is required when access_mode=subscription"}
		}
		if req.SubscriptionDays <= 0 {
			return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "subscription_days is required when access_mode=subscription"}
		}
	case "self_service":
		if strings.TrimSpace(req.ProbeAPIKey) == "" {
			return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "probe_api_key is required when access_mode=self_service"}
		}
	default:
		return &httpError{StatusCode: http.StatusBadRequest, Code: "invalid_request", Message: "access_mode must be subscription or self_service"}
	}
	return nil
}

func parsePositiveInt(raw string) int {
	value, err := strconv.Atoi(strings.TrimSpace(raw))
	if err != nil || value <= 0 {
		return 0
	}
	return value
}

func defaultPositiveInt(value, fallback int) int {
	if value > 0 {
		return value
	}
	return fallback
}