package main

import (
	"context"
	"flag"
	"fmt"
	"io"
	"os"
	"strings"
	"time"

	"sub2api-cn-relay-manager/internal/app"
	"sub2api-cn-relay-manager/internal/config"
)

type batchImportFunc func(context.Context, batchImportCLIRequest) (batchImportCLIResult, error)

type batchImportCLIEntry struct {
	BaseURL         string
	APIKey          string
	RequestedModels []string
}

type batchImportCLIRequest struct {
	HostID                string
	Mode                  string
	AccessMode            string
	ConfirmWaitTimeoutSec int
	SubscriptionUsers     []string
	SubscriptionDays      int
	ProbeAPIKey           string
	Entries               []batchImportCLIEntry
}

type batchImportCLIResult struct {
	RunID      string
	ResultPage string
}

func parseBatchImportCLIArgs(args []string) (batchImportCLIRequest, error) {
	fs := flag.NewFlagSet("batch-import", flag.ContinueOnError)
	fs.SetOutput(io.Discard)

	var req batchImportCLIRequest
	var entryValues cliStringList
	var batchFile string
	var subscriptionUsersCSV string
	var confirmTimeoutRaw string

	fs.StringVar(&req.HostID, "host-id", "", "")
	fs.Var(&entryValues, "entry", "")
	fs.StringVar(&batchFile, "batch-file", "", "")
	fs.StringVar(&req.Mode, "mode", "partial", "")
	fs.StringVar(&req.AccessMode, "access-mode", "self_service", "")
	fs.StringVar(&subscriptionUsersCSV, "subscription-users", "", "")
	fs.IntVar(&req.SubscriptionDays, "subscription-days", 0, "")
	fs.StringVar(&req.ProbeAPIKey, "probe-api-key", "", "")
	fs.StringVar(&confirmTimeoutRaw, "confirm-timeout", "", "")
	fs.StringVar(&confirmTimeoutRaw, "confirm-wait-timeout", "", "")
	if err := fs.Parse(args); err != nil {
		return batchImportCLIRequest{}, err
	}

	req.SubscriptionUsers = splitCSV(subscriptionUsersCSV)

	entries := make([]batchImportCLIEntry, 0, len(entryValues))
	for _, raw := range entryValues {
		entry, err := parseBatchImportEntry(raw)
		if err != nil {
			return batchImportCLIRequest{}, err
		}
		entries = append(entries, entry)
	}
	if strings.TrimSpace(batchFile) != "" {
		fileEntries, err := parseBatchImportFile(batchFile)
		if err != nil {
			return batchImportCLIRequest{}, err
		}
		entries = append(entries, fileEntries...)
	}
	req.Entries = entries

	if strings.TrimSpace(confirmTimeoutRaw) != "" {
		duration, err := time.ParseDuration(strings.TrimSpace(confirmTimeoutRaw))
		if err != nil {
			return batchImportCLIRequest{}, fmt.Errorf("--confirm-timeout is invalid: %w", err)
		}
		if duration <= 0 {
			return batchImportCLIRequest{}, fmt.Errorf("--confirm-timeout must be positive")
		}
		req.ConfirmWaitTimeoutSec = int(duration / time.Second)
		if req.ConfirmWaitTimeoutSec == 0 {
			req.ConfirmWaitTimeoutSec = 1
		}
	}

	switch {
	case strings.TrimSpace(req.HostID) == "":
		return batchImportCLIRequest{}, fmt.Errorf("--host-id is required")
	case len(req.Entries) == 0:
		return batchImportCLIRequest{}, fmt.Errorf("--entry or --batch-file is required")
	case strings.TrimSpace(req.Mode) == "":
		return batchImportCLIRequest{}, fmt.Errorf("--mode is required")
	case strings.TrimSpace(req.AccessMode) == "":
		return batchImportCLIRequest{}, fmt.Errorf("--access-mode is required")
	}

	switch strings.TrimSpace(req.AccessMode) {
	case "subscription":
		switch {
		case len(req.SubscriptionUsers) == 0:
			return batchImportCLIRequest{}, fmt.Errorf("--subscription-users is required when --access-mode=subscription")
		case req.SubscriptionDays <= 0:
			return batchImportCLIRequest{}, fmt.Errorf("--subscription-days is required when --access-mode=subscription")
		}
	case "self_service":
		if strings.TrimSpace(req.ProbeAPIKey) == "" {
			return batchImportCLIRequest{}, fmt.Errorf("--probe-api-key is required when --access-mode=self_service")
		}
	default:
		return batchImportCLIRequest{}, fmt.Errorf("--access-mode must be subscription or self_service")
	}

	return req, nil
}

func runBatchImport(ctx context.Context, req batchImportCLIRequest) (batchImportCLIResult, error) {
	startupConfig, err := config.LoadStartupFromEnv()
	if err != nil {
		return batchImportCLIResult{}, err
	}

	entries := make([]app.BatchImportEntryRequest, 0, len(req.Entries))
	for _, entry := range req.Entries {
		entries = append(entries, app.BatchImportEntryRequest{
			BaseURL:         entry.BaseURL,
			APIKey:          entry.APIKey,
			RequestedModels: append([]string(nil), entry.RequestedModels...),
		})
	}

	actionSet := app.NewActionSet(startupConfig.Database.SQLiteDSN)
	result, err := actionSet.CreateBatchImportRun(ctx, app.CreateBatchImportRunRequest{
		HostID:                req.HostID,
		Mode:                  req.Mode,
		AccessMode:            req.AccessMode,
		ConfirmWaitTimeoutSec: req.ConfirmWaitTimeoutSec,
		SubscriptionUsers:     append([]string(nil), req.SubscriptionUsers...),
		SubscriptionDays:      req.SubscriptionDays,
		ProbeAPIKey:           req.ProbeAPIKey,
		Entries:               entries,
	})
	if err != nil {
		return batchImportCLIResult{}, err
	}

	return batchImportCLIResult{
		RunID:      result.RunID,
		ResultPage: result.ResultPage,
	}, nil
}

func parseBatchImportEntry(raw string) (batchImportCLIEntry, error) {
	parts := strings.SplitN(strings.TrimSpace(raw), ",", 3)
	if len(parts) < 2 {
		return batchImportCLIEntry{}, fmt.Errorf("--entry must be base_url,api_key[,requested_model|requested_model]")
	}

	entry := batchImportCLIEntry{
		BaseURL: strings.TrimSpace(parts[0]),
		APIKey:  strings.TrimSpace(parts[1]),
	}
	if entry.BaseURL == "" || entry.APIKey == "" {
		return batchImportCLIEntry{}, fmt.Errorf("--entry must include non-empty base_url and api_key")
	}
	if len(parts) == 3 {
		entry.RequestedModels = splitPipeCSV(parts[2])
	}
	return entry, nil
}

func parseBatchImportFile(path string) ([]batchImportCLIEntry, error) {
	content, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read batch file %q: %w", path, err)
	}

	lines := strings.Split(string(content), "\n")
	entries := make([]batchImportCLIEntry, 0, len(lines))
	for _, line := range lines {
		trimmed := strings.TrimSpace(line)
		if trimmed == "" || strings.HasPrefix(trimmed, "#") {
			continue
		}
		entry, err := parseBatchImportEntry(trimmed)
		if err != nil {
			return nil, fmt.Errorf("parse batch file %q: %w", path, err)
		}
		entries = append(entries, entry)
	}
	return entries, nil
}

type cliStringList []string

func (l *cliStringList) String() string {
	return strings.Join(*l, ",")
}

func (l *cliStringList) Set(value string) error {
	*l = append(*l, value)
	return nil
}

func splitPipeCSV(value string) []string {
	value = strings.ReplaceAll(value, "|", ",")
	return splitCSV(value)
}