package plugins

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"strconv"
)

var openCodeScriptPathPattern = regexp.MustCompile(`(?m)^const (GUARD_SCRIPT_PATH|HOOK_SCRIPT_PATH) = (".*");$`)

// OpenCodePlugin writes ~/.config/opencode/plugins/elydora-audit.mjs.
type OpenCodePlugin struct{}

func (p *OpenCodePlugin) configPath() (string, error) {
	home, err := os.UserHomeDir()
	if err != nil {
		return "", fmt.Errorf("resolve home directory: %w", err)
	}
	return filepath.Join(home, ".config", "opencode", "plugins", "elydora-audit.mjs"), nil
}

func (p *OpenCodePlugin) Install(config InstallConfig) error {
	scriptPath, err := hookScriptPath(config.AgentID)
	if err != nil {
		return err
	}
	if config.HookScript != "" {
		scriptPath = config.HookScript
	}

	if err := GenerateHookScript(scriptPath, config); err != nil {
		return fmt.Errorf("generate hook script: %w", err)
	}

	guardPath := config.GuardScriptPath
	if guardPath == "" {
		guardPath, err = guardScriptPath(config.AgentID)
		if err != nil {
			return err
		}
	}

	pluginFile, err := p.configPath()
	if err != nil {
		return err
	}
	dir := filepath.Dir(pluginFile)
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("create directory %s: %w", dir, err)
	}

	content := buildOpenCodePlugin(scriptPath, guardPath)
	if err := os.WriteFile(pluginFile, []byte(content), 0644); err != nil {
		return fmt.Errorf("write %s: %w", pluginFile, err)
	}

	fmt.Printf("Installed Elydora hook for OpenCode at %s\n", pluginFile)
	return nil
}

func buildOpenCodePlugin(scriptPath, guardPath string) string {
	return fmt.Sprintf(`// Elydora audit plugin for OpenCode. Generated by the Elydora CLI; do not edit.

import { spawn, spawnSync } from 'node:child_process';

const GUARD_SCRIPT_PATH = %q;
const HOOK_SCRIPT_PATH = %q;

export const ElydoraAuditPlugin = async () => ({
  "tool.execute.before": async () => {
    const result = spawnSync('node', [GUARD_SCRIPT_PATH], {
      timeout: 5000,
      stdio: ['pipe', 'ignore', 'pipe'],
    });
    if (result.error) {
      throw new Error('Elydora guard failed: ' + result.error.message);
    }
    if (result.status !== 0) {
      const message = result.stderr?.toString().trim() || 'Elydora guard blocked tool execution.';
      throw new Error(message);
    }
  },

  "tool.execute.after": async (input) => {
    const event = JSON.stringify({
      tool_name: input?.tool || 'unknown',
      tool_input: input?.args || {},
      session_id: input?.sessionID || 'unknown',
    });
    const child = spawn('node', [HOOK_SCRIPT_PATH], {
      detached: true,
      stdio: ['pipe', 'ignore', 'ignore'],
    });
    child.on('error', (error) => {
      console.error('[elydora] audit hook failed:', error.message);
    });
    child.stdin.end(event);
    child.unref();
  },
});
`, guardPath, scriptPath)
}

func (p *OpenCodePlugin) Uninstall(agentID string) error {
	pluginFile, err := p.configPath()
	if err != nil {
		return err
	}
	if err := os.Remove(pluginFile); err != nil && !os.IsNotExist(err) {
		return fmt.Errorf("remove %s: %w", pluginFile, err)
	}

	if agentID != "" {
		if err := removeAgentScripts(agentID); err != nil {
			return err
		}
	}
	fmt.Println("Uninstalled Elydora hook for OpenCode.")
	return nil
}

func openCodeScriptPaths(data []byte, pluginFile string) (string, string, error) {
	paths := map[string]string{}
	for _, match := range openCodeScriptPathPattern.FindAllSubmatch(data, -1) {
		value, err := strconv.Unquote(string(match[2]))
		if err != nil {
			return "", "", fmt.Errorf(
				"OpenCode plugin at %s has an invalid %s: %w", pluginFile, match[1], err,
			)
		}
		paths[string(match[1])] = value
	}
	guardPath, hasGuard := paths["GUARD_SCRIPT_PATH"]
	hookPath, hasHook := paths["HOOK_SCRIPT_PATH"]
	if !hasGuard || !hasHook {
		return "", "", fmt.Errorf("OpenCode plugin at %s has no Elydora script paths", pluginFile)
	}
	return guardPath, hookPath, nil
}

func (p *OpenCodePlugin) Status() (PluginStatus, error) {
	pluginFile, err := p.configPath()
	if err != nil {
		return PluginStatus{}, err
	}
	status := PluginStatus{
		AgentName:   "opencode",
		DisplayName: "OpenCode",
		ConfigPath:  pluginFile,
	}
	data, err := os.ReadFile(pluginFile)
	if errors.Is(err, os.ErrNotExist) {
		return status, nil
	}
	if err != nil {
		return status, fmt.Errorf("read %s: %w", pluginFile, err)
	}
	status.HookConfigured = true
	guardPath, hookPath, err := openCodeScriptPaths(data, pluginFile)
	if err != nil {
		return status, err
	}
	guard, err := resolveManagedScript(guardPath, "guard.js")
	if err != nil {
		return status, err
	}
	audit, err := resolveManagedScript(hookPath, "hook.js")
	if err != nil {
		return status, err
	}
	if guard == nil || audit == nil || !sameManagedAgentID(guard.agentID, audit.agentID) {
		return status, nil
	}
	status.HookScriptExists, err = managedRuntimePresent(managedRuntimeContract{
		agentID: guard.agentID, guardPath: guard.scriptPath, auditPath: audit.scriptPath,
	}, "opencode")
	if err != nil {
		return status, err
	}
	status.Installed = status.HookScriptExists
	return status, nil
}