package plugin

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"
	"sync"

	"gopkg.in/yaml.v3"
)

const (
	PluginID       = "commandcode"
	PluginName     = "commandcode"
	PluginVersion  = "0.2.1"
	PluginAuthor   = "zgs225"
	PluginRepo     = "https://github.com/zgs225/cliproxy-plugin-commandcode"
	PluginLogo     = "https://raw.githubusercontent.com/zgs225/cliproxy-plugin-commandcode/main/assets/logo.svg"
	SchemaVersion1 = 1
)

// PluginConfig holds the runtime configuration parsed from YAML.
type PluginConfig struct {
	mu           sync.RWMutex
	SessionToken string `yaml:"session_token" json:"session_token"`
	APIBase      string `yaml:"api_base" json:"api_base"`
}

// UpdateFromYAML updates the configuration from raw YAML bytes.
func (c *PluginConfig) UpdateFromYAML(raw []byte) error {
	if len(raw) == 0 {
		return nil
	}
	var tmp struct {
		SessionToken string `yaml:"session_token"`
		APIBase      string `yaml:"api_base"`
	}
	if err := yaml.Unmarshal(raw, &tmp); err != nil {
		return fmt.Errorf("unmarshal config_yaml: %w", err)
	}

	c.mu.Lock()
	defer c.mu.Unlock()

	if tmp.SessionToken != "" {
		c.SessionToken = ExtractSessionToken(tmp.SessionToken)
	}
	if tmp.APIBase != "" {
		c.APIBase = strings.TrimRight(tmp.APIBase, "/")
	}
	if c.APIBase == "" {
		c.APIBase = DefaultAPIBase
	}
	return nil
}

// GetSessionToken safely returns the session token.
func (c *PluginConfig) GetSessionToken() string {
	c.mu.RLock()
	defer c.mu.RUnlock()
	return c.SessionToken
}

// SetSessionToken safely sets the session token.
func (c *PluginConfig) SetSessionToken(token string) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.SessionToken = ExtractSessionToken(token)
}

// GetAPIBase safely returns the API base URL.
func (c *PluginConfig) GetAPIBase() string {
	c.mu.RLock()
	defer c.mu.RUnlock()
	if c.APIBase == "" {
		return DefaultAPIBase
	}
	return c.APIBase
}

// Plugin encapsulates the Command Code plugin instance.
type Plugin struct {
	config *PluginConfig
}

var (
	defaultPlugin = NewPlugin()
)

// DefaultPlugin returns the singleton plugin instance.
func DefaultPlugin() *Plugin {
	return defaultPlugin
}

// NewPlugin creates a new Plugin instance.
func NewPlugin() *Plugin {
	return &Plugin{
		config: &PluginConfig{
			APIBase: DefaultAPIBase,
		},
	}
}

// HandleMethod dispatches an ABI call to the corresponding handler.
func (p *Plugin) HandleMethod(method string, requestBytes []byte) ([]byte, error) {
	switch method {
	case "plugin.register":
		return p.handleRegister(requestBytes)
	case "plugin.reconfigure":
		return p.handleReconfigure(requestBytes)
	case "plugin.quiesce", "plugin.shutdown":
		return OkEnvelope(map[string]any{"shutdown": true})

	case "management.register":
		return p.handleManagementRegister()
	case "management.handle":
		return p.handleManagementHandle(requestBytes)

	default:
		return ErrorEnvelope("unknown_method", "unknown method: "+method), nil
	}
}

func (p *Plugin) handleRegister(raw []byte) ([]byte, error) {
	if len(raw) > 0 {
		var req LifecycleRequest
		if err := json.Unmarshal(raw, &req); err == nil && len(req.ConfigYAML) > 0 {
			_ = p.config.UpdateFromYAML(req.ConfigYAML)
		}
	}
	return OkEnvelope(Registration{
		SchemaVersion: SchemaVersion1,
		Metadata: Metadata{
			Name:             PluginName,
			Version:          PluginVersion,
			Author:           PluginAuthor,
			GitHubRepository: PluginRepo,
			Logo:             PluginLogo,
			ConfigFields: []ConfigField{
				{
					Name:        "session_token",
					Type:        "string",
					Description: "Command Code session token (__Secure-commandcode_prod_.session_token cookie value)",
				},
				{
					Name:        "api_base",
					Type:        "string",
					Description: "Command Code API base URL (default: https://api.commandcode.ai)",
				},
			},
		},
		Capabilities: RegistrationCapability{
			ManagementAPI: true,
		},
	})
}

func (p *Plugin) handleReconfigure(raw []byte) ([]byte, error) {
	if len(raw) > 0 {
		var req LifecycleRequest
		if err := json.Unmarshal(raw, &req); err == nil && len(req.ConfigYAML) > 0 {
			_ = p.config.UpdateFromYAML(req.ConfigYAML)
		}
	}
	return p.handleRegister(raw)
}

func (p *Plugin) handleManagementRegister() ([]byte, error) {
	resp, err := RegisterManagement()
	if err != nil {
		return ErrorEnvelope("management_register_error", err.Error()), nil
	}
	return OkEnvelope(resp)
}

func (p *Plugin) handleManagementHandle(raw []byte) ([]byte, error) {
	var req ManagementRequest
	if len(raw) > 0 {
		if err := json.Unmarshal(raw, &req); err != nil {
			return ErrorEnvelope("invalid_request", "failed to parse ManagementRequest: "+err.Error()), nil
		}
	}

	resp, err := HandleManagement(context.Background(), req, p.config)
	if err != nil {
		return ErrorEnvelope("management_handle_error", err.Error()), nil
	}
	return OkEnvelope(resp)
}

// OkEnvelope builds a successful Envelope response.
func OkEnvelope(v any) ([]byte, error) {
	raw, err := json.Marshal(v)
	if err != nil {
		return nil, err
	}
	return json.Marshal(Envelope{OK: true, Result: raw})
}

// ErrorEnvelope builds an error Envelope response.
func ErrorEnvelope(code, message string) []byte {
	raw, _ := json.Marshal(Envelope{
		OK: false,
		Error: &EnvelopeError{
			Code:    code,
			Message: message,
		},
	})
	return raw
}