package config

import (
	"bufio"
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"
)

var volcAccountNames = strings.Fields(`VOLC_ACCESS_KEY_ID VOLC_SECRET_ACCESS_KEY VOLC_SESSION_TOKEN VOLC_RTC_BASE_URL VOLC_RTC_REGION VOLC_RTC_API_VERSION RTC_APP_ID RTC_APP_KEY RTC_TOKEN_ISSUER VOLC_HARDWARE_INSTANCE_ID VOLC_HARDWARE_PRODUCT_KEY VOLC_HARDWARE_PRODUCT_SECRET VOLC_HARDWARE_AGENT_BOT_ID VOLC_HARDWARE_PROVISIONING_ENABLED VOLC_HARDWARE_AGENT_TRANSPORT VOLC_HARDWARE_AGENT_MINIMUM_SDK_VERSION VOLC_HARDWARE_REGISTER_URL VOLC_HARDWARE_DEVICE_NAME_PREFIX MIGRATION_HARDWARE_RTC_APP_ID MIGRATION_HARDWARE_LICENSE_READY S2S_APP_ID S2S_ACCESS_TOKEN S2S_MODEL S2S_SPEAKER VIKING_MEMORY_RESOURCE_ID VIKING_MEMORY_API_KEY VIKING_MEMORY_COLLECTION_NAME VIKING_MEMORY_EVENT_TYPE VIKING_MEMORY_PROFILE_TYPE TOS_RECORDING_ACCOUNT_ID TOS_RECORDING_BUCKET TOS_RECORDING_REGION TOS_RECORDING_PLAYBACK_ENDPOINT ARK_API_KEY ARK_BASE_URL ARK_CONTENT_MODEL ARK_EMBEDDING_MODEL CONTENT_GENERATOR EMBEDDING_PROVIDER VOLC_SUBTITLE_CALLBACK_URL VOLC_SUBTITLE_PRIMARY MIGRATION_NOTES`)

// ReadVolcAccountFile reads a literal worksheet, never shell commands or expansion.
// Errors identify the field/line only; credentials must never enter logs.
func ReadVolcAccountFile(path string) (map[string]string, error) {
	if !filepath.IsAbs(path) {
		return nil, errors.New("VOLC_ACCOUNT_CONFIG_FILE must be absolute")
	}
	raw, err := os.ReadFile(path)
	if err != nil {
		return nil, errors.New("Volc account configuration unavailable")
	}
	if len(raw) > 65536 {
		return nil, errors.New("Volc account configuration too large")
	}
	allowed := map[string]bool{}
	for _, name := range volcAccountNames {
		allowed[name] = true
	}
	values := map[string]string{}
	s := bufio.NewScanner(bytes.NewReader(bytes.TrimPrefix(raw, []byte{0xef, 0xbb, 0xbf})))
	line := 0
	for s.Scan() {
		line++
		text := strings.TrimSpace(s.Text())
		if text == "" || strings.HasPrefix(text, "#") {
			continue
		}
		name, value, ok := strings.Cut(text, "=")
		name = strings.TrimSpace(name)
		if !ok || !allowed[name] {
			return nil, fmt.Errorf("Volc account configuration invalid field at line %d", line)
		}
		if _, found := values[name]; found {
			return nil, fmt.Errorf("Volc account configuration duplicate %s", name)
		}
		value = strings.TrimSpace(value)
		if len(value) >= 2 && ((value[0] == '\'' && value[len(value)-1] == '\'') || (value[0] == '"' && value[len(value)-1] == '"')) {
			value = value[1 : len(value)-1]
		}
		if strings.ContainsAny(value, "\x00\r\n") {
			return nil, fmt.Errorf("Volc account configuration invalid %s", name)
		}
		values[name] = value
	}
	if s.Err() != nil {
		return nil, errors.New("Volc account configuration unreadable")
	}
	for _, name := range volcAccountNames {
		if strings.HasPrefix(name, "MIGRATION_") {
			continue
		}
		if _, found := values[name]; !found {
			return nil, fmt.Errorf("Volc account configuration missing %s", name)
		}
	}
	return values, nil
}

func loadVolcAccount() (map[string]string, error) {
	path := strings.TrimSpace(os.Getenv("VOLC_ACCOUNT_CONFIG_FILE"))
	if path == "" {
		return nil, nil
	}
	return ReadVolcAccountFile(path)
}

func loadSecretValuesWithAccount(account map[string]string, names ...string) (map[string]string, error) {
	values := make(map[string]string, len(names))
	for _, name := range names {
		if value, found := account[name]; found {
			values[name] = value
			continue
		}
		value, err := secretEnv(name)
		if err != nil {
			return nil, err
		}
		values[name] = value
	}
	return values, nil
}

func (c *Config) applyVolcAccount(values map[string]string) error {
	c.TOSRecordingAccountID = strings.TrimSpace(os.Getenv("TOS_RECORDING_ACCOUNT_ID"))
	c.TOSRecordingBucket = strings.TrimSpace(os.Getenv("TOS_RECORDING_BUCKET"))
	c.TOSRecordingRegion = strings.TrimSpace(os.Getenv("TOS_RECORDING_REGION"))
	c.TOSRecordingPlaybackEndpoint = strings.TrimSpace(os.Getenv("TOS_RECORDING_PLAYBACK_ENDPOINT"))
	if values == nil {
		return nil
	}
	c.volcAccount = values
	fields := map[string]*string{
		"VOLC_ACCESS_KEY_ID": &c.VolcAccessKeyID, "VOLC_SECRET_ACCESS_KEY": &c.VolcSecretAccessKey, "VOLC_SESSION_TOKEN": &c.VolcSessionToken,
		"RTC_APP_ID": &c.RTCAppID, "RTC_APP_KEY": &c.RTCAppKey, "RTC_TOKEN_ISSUER": &c.RTCTokenIssuer,
		"VOLC_RTC_BASE_URL": &c.VolcRTCBaseURL, "VOLC_RTC_REGION": &c.VolcRTCRegion, "VOLC_RTC_API_VERSION": &c.VolcRTCAPIVersion,
		"VOLC_HARDWARE_INSTANCE_ID": &c.VolcHardwareInstanceID, "VOLC_HARDWARE_PRODUCT_KEY": &c.VolcHardwareProductKey, "VOLC_HARDWARE_PRODUCT_SECRET": &c.VolcHardwareProductSecret,
		"VOLC_HARDWARE_AGENT_BOT_ID": &c.VolcHardwareAgentBotID, "VOLC_HARDWARE_AGENT_TRANSPORT": &c.VolcHardwareTransport, "VOLC_HARDWARE_AGENT_MINIMUM_SDK_VERSION": &c.VolcHardwareMinimumSDKVersion,
		"VOLC_HARDWARE_REGISTER_URL": &c.VolcHardwareRegisterURL, "VOLC_HARDWARE_DEVICE_NAME_PREFIX": &c.VolcHardwareDeviceNamePrefix,
		"VIKING_MEMORY_RESOURCE_ID": &c.VikingResourceID, "VIKING_MEMORY_API_KEY": &c.VikingAPIKey, "VIKING_MEMORY_COLLECTION_NAME": &c.VikingCollectionName,
		"VIKING_MEMORY_EVENT_TYPE": &c.VikingEventType, "VIKING_MEMORY_PROFILE_TYPE": &c.VikingProfileType,
		"TOS_RECORDING_ACCOUNT_ID": &c.TOSRecordingAccountID, "TOS_RECORDING_BUCKET": &c.TOSRecordingBucket, "TOS_RECORDING_REGION": &c.TOSRecordingRegion, "TOS_RECORDING_PLAYBACK_ENDPOINT": &c.TOSRecordingPlaybackEndpoint,
		"ARK_API_KEY": &c.ArkAPIKey, "ARK_BASE_URL": &c.ArkBaseURL, "ARK_CONTENT_MODEL": &c.ArkContentModel, "ARK_EMBEDDING_MODEL": &c.ArkEmbeddingModel,
		"CONTENT_GENERATOR": &c.ContentGenerator, "EMBEDDING_PROVIDER": &c.EmbeddingProvider, "VOLC_SUBTITLE_CALLBACK_URL": &c.SubtitleCallbackURL,
	}
	for name, field := range fields {
		*field = values[name]
	}
	for name, field := range map[string]*bool{"VOLC_HARDWARE_PROVISIONING_ENABLED": &c.VolcHardwareProvisioningEnabled, "VOLC_SUBTITLE_PRIMARY": &c.SubtitlePrimary} {
		parsed, err := strconv.ParseBool(values[name])
		if err != nil {
			return fmt.Errorf("Volc account configuration invalid boolean %s", name)
		}
		*field = parsed
	}
	for _, name := range []string{"VOLC_ACCESS_KEY_ID", "VOLC_SECRET_ACCESS_KEY", "RTC_APP_ID", "RTC_APP_KEY", "S2S_APP_ID", "S2S_ACCESS_TOKEN", "S2S_MODEL", "S2S_SPEAKER"} {
		if values[name] == "" {
			return fmt.Errorf("Volc account configuration requires %s", name)
		}
	}
	return nil
}

// ApplyVolcVoiceTemplate supplies credentials from the account file at startup.
// Templates retain prompts and behaviour but are never an alternative key source.
func (c Config) ApplyVolcVoiceTemplate(raw []byte) ([]byte, error) {
	if c.volcAccount == nil {
		return raw, nil
	}
	var root map[string]any
	if json.Unmarshal(raw, &root) != nil {
		return nil, errors.New("invalid Volc voice template")
	}
	items := []map[string]any{root}
	if bundle, ok := root["templates"].(map[string]any); ok {
		items = nil
		for _, entry := range bundle {
			item, ok := entry.(map[string]any)
			if !ok {
				return nil, errors.New("invalid Volc voice template entry")
			}
			items = append(items, item)
		}
	}
	updated := 0
	for _, item := range items {
		conf, _ := item["Config"].(map[string]any)
		s2s, _ := conf["S2SConfig"].(map[string]any)
		if s2s == nil {
			continue
		}
		pp, _ := s2s["ProviderParams"].(map[string]any)
		if pp == nil {
			pp = map[string]any{}
			s2s["ProviderParams"] = pp
		}
		app, _ := pp["app"].(map[string]any)
		if app == nil {
			app = map[string]any{}
			pp["app"] = app
		}
		app["appid"] = c.volcAccount["S2S_APP_ID"]
		app["token"] = c.volcAccount["S2S_ACCESS_TOKEN"]
		dialog, _ := pp["dialog"].(map[string]any)
		if dialog == nil {
			dialog = map[string]any{}
			pp["dialog"] = dialog
		}
		extra, _ := dialog["extra"].(map[string]any)
		if extra == nil {
			extra = map[string]any{}
			dialog["extra"] = extra
		}
		extra["model"] = c.volcAccount["S2S_MODEL"]
		tts, _ := pp["tts"].(map[string]any)
		if tts == nil {
			tts = map[string]any{}
			pp["tts"] = tts
		}
		tts["speaker"] = c.volcAccount["S2S_SPEAKER"]
		conf["MemoryConfig"] = map[string]any{"Enable": false}
		updated++
	}
	if updated == 0 {
		return nil, errors.New("Volc account requires an S2S voice template")
	}
	return json.Marshal(root)
}