package manager

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

	"git.yeij.top/AskaEth/Cyrene-Plugins/sdk"
)

// CtxKeyIsAdmin is the context key for the admin flag.
type ctxKey string

const CtxKeyIsAdmin ctxKey = "isAdmin"

// adminOnlyTools lists tools that require admin permission to execute.
var adminOnlyTools = map[string]bool{
	"host_exec": true,
	"os_exec":   true,
	"host_file": true,
}

// IsAdminFromCtx returns true if the context carries an admin flag.
func IsAdminFromCtx(ctx context.Context) bool {
	v, _ := ctx.Value(CtxKeyIsAdmin).(bool)
	return v
}

// CallLogRecord 工具调用记录
type CallLogRecord struct {
	CallID     string `json:"call_id"`
	ToolName   string `json:"tool_name"`
	Arguments  string `json:"arguments"`
	Output     string `json:"output"`
	Error      string `json:"error"`
	Success    bool   `json:"success"`
	DurationMs int    `json:"duration_ms"`
	Timestamp  int64  `json:"timestamp"`
}

// callLogRing 线程安全的环形缓冲区
type callLogRing struct {
	mu       sync.Mutex
	records  []CallLogRecord
	capacity int
	head     int
	size     int
}

func newCallLogRing(capacity int) *callLogRing {
	return &callLogRing{capacity: capacity, records: make([]CallLogRecord, capacity)}
}

func (r *callLogRing) push(rec CallLogRecord) {
	r.mu.Lock()
	defer r.mu.Unlock()
	rec.CallID = fmt.Sprintf("%d", time.Now().UnixNano())
	rec.Timestamp = time.Now().UnixMilli()
	r.records[r.head] = rec
	r.head = (r.head + 1) % r.capacity
	if r.size < r.capacity {
		r.size++
	}
}

func (r *callLogRing) getAll() []CallLogRecord {
	r.mu.Lock()
	defer r.mu.Unlock()
	result := make([]CallLogRecord, r.size)
	for i := 0; i < r.size; i++ {
		idx := (r.head - 1 - i) % r.capacity
		if idx < 0 {
			idx += r.capacity
		}
		result[i] = r.records[idx]
	}
	return result
}

func (r *callLogRing) statsByTool() map[string]map[string]interface{} {
	r.mu.Lock()
	defer r.mu.Unlock()
	byTool := make(map[string]map[string]interface{})
	for i := 0; i < r.size; i++ {
		idx := (r.head - 1 - i) % r.capacity
		if idx < 0 {
			idx += r.capacity
		}
		rec := r.records[idx]
		if _, ok := byTool[rec.ToolName]; !ok {
			byTool[rec.ToolName] = map[string]interface{}{
				"tool_name": rec.ToolName, "count": 0, "success_count": 0,
				"fail_count": 0, "total_duration_ms": 0,
			}
		}
		s := byTool[rec.ToolName]
		s["count"] = s["count"].(int) + 1
		if rec.Success {
			s["success_count"] = s["success_count"].(int) + 1
		} else {
			s["fail_count"] = s["fail_count"].(int) + 1
		}
		s["total_duration_ms"] = s["total_duration_ms"].(int) + rec.DurationMs
	}
	return byTool
}

// ToolRegistry aggregates tool definitions from all running plugins and dispatches execution.
type ToolRegistry struct {
	mu      sync.RWMutex
	tools   map[string]sdk.Tool // tool ID -> Tool
	callLog *callLogRing
	enabled bool
}

func NewToolRegistry() *ToolRegistry {
	return &ToolRegistry{
		tools:   make(map[string]sdk.Tool),
		callLog: newCallLogRing(500),
		enabled: true,
	}
}

// IsEnabled returns whether tool execution is enabled.
func (r *ToolRegistry) IsEnabled() bool {
	r.mu.RLock()
	defer r.mu.RUnlock()
	return r.enabled
}

// SetEnabled enables or disables tool execution.
func (r *ToolRegistry) SetEnabled(enabled bool) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.enabled = enabled
}

// DefinitionNames returns all registered tool names.
func (r *ToolRegistry) DefinitionNames() []string {
	r.mu.RLock()
	defer r.mu.RUnlock()
	names := make([]string, 0, len(r.tools))
	for id := range r.tools {
		names = append(names, id)
	}
	return names
}

func (r *ToolRegistry) Register(tool sdk.Tool) error {
	r.mu.Lock()
	defer r.mu.Unlock()
	id := tool.Definition().ID
	if _, exists := r.tools[id]; exists {
		return fmt.Errorf("tool %q already registered", id)
	}
	r.tools[id] = tool
	return nil
}

func (r *ToolRegistry) Unregister(toolID string) {
	r.mu.Lock()
	defer r.mu.Unlock()
	delete(r.tools, toolID)
}

func (r *ToolRegistry) Get(toolID string) (sdk.Tool, bool) {
	r.mu.RLock()
	defer r.mu.RUnlock()
	t, ok := r.tools[toolID]
	return t, ok
}

func (r *ToolRegistry) List() []sdk.Tool {
	r.mu.RLock()
	defer r.mu.RUnlock()
	result := make([]sdk.Tool, 0, len(r.tools))
	for _, t := range r.tools {
		result = append(result, t)
	}
	return result
}

func (r *ToolRegistry) Definitions() []sdk.ToolDefinition {
	r.mu.RLock()
	defer r.mu.RUnlock()
	defs := make([]sdk.ToolDefinition, 0, len(r.tools))
	for _, t := range r.tools {
		defs = append(defs, t.Definition())
	}
	return defs
}

func (r *ToolRegistry) Execute(ctx context.Context, toolID string, args map[string]interface{}) (*sdk.ToolResult, error) {
	r.mu.RLock()
	tool, ok := r.tools[toolID]
	r.mu.RUnlock()

	startTime := time.Now()

	if !ok {
		r.callLog.push(CallLogRecord{
			ToolName: toolID, Error: fmt.Sprintf("tool %q not found", toolID),
			Success: false, DurationMs: int(time.Since(startTime).Milliseconds()),
		})
		return nil, fmt.Errorf("tool %q not found", toolID)
	}

	if err := tool.Validate(args); err != nil {
		r.callLog.push(CallLogRecord{
			ToolName: toolID, Error: err.Error(), Success: false,
			DurationMs: int(time.Since(startTime).Milliseconds()),
		})
		return &sdk.ToolResult{Success: false, Error: err.Error()}, nil
	}

	// Admin-only tools: deny non-admin callers.
	if adminOnlyTools[toolID] && !IsAdminFromCtx(ctx) {
		errMsg := fmt.Sprintf("工具 %s 仅限管理员使用", toolID)
		r.callLog.push(CallLogRecord{
			ToolName: toolID, Error: errMsg, Success: false,
			DurationMs: int(time.Since(startTime).Milliseconds()),
		})
		return &sdk.ToolResult{Success: false, Error: errMsg}, nil
	}

	result, err := tool.Execute(ctx, args)
	durationMs := int(time.Since(startTime).Milliseconds())

	if err != nil {
		r.callLog.push(CallLogRecord{
			ToolName: toolID, Error: err.Error(), Success: false, DurationMs: durationMs,
		})
		return result, err
	}

	var argsJSON string
	if args != nil {
		if b, _ := json.Marshal(args); b != nil {
			argsJSON = string(b)
		}
	}
	r.callLog.push(CallLogRecord{
		ToolName: toolID, Arguments: argsJSON, Output: result.Output,
		Error: result.Error, Success: result.Success, DurationMs: durationMs,
	})

	return result, nil
}

// UnregisterAll removes all tools matching given IDs.
func (r *ToolRegistry) UnregisterAll(toolIDs []string) {
	r.mu.Lock()
	defer r.mu.Unlock()
	for _, id := range toolIDs {
		delete(r.tools, id)
	}
}

// GetCallLogs 获取工具调用记录（最新在前，支持按工具名过滤、分页）
func (r *ToolRegistry) GetCallLogs(toolName string, limit, offset int) ([]CallLogRecord, int) {
	all := r.callLog.getAll()

	// 过滤
	var filtered []CallLogRecord
	if toolName == "" {
		filtered = all
	} else {
		filtered = make([]CallLogRecord, 0)
		for _, rec := range all {
			if rec.ToolName == toolName {
				filtered = append(filtered, rec)
			}
		}
	}

	total := len(filtered)

	// 分页
	if offset >= len(filtered) {
		return []CallLogRecord{}, total
	}
	page := filtered[offset:]
	if limit > 0 && limit < len(page) {
		page = page[:limit]
	}

	return page, total
}

// GetCallStats 获取工具调用统计
func (r *ToolRegistry) GetCallStats() map[string]interface{} {
	byTool := r.callLog.statsByTool()
	totalCalls, successCount, failCount, totalDurationMs := 0, 0, 0, 0
	toolStats := make([]map[string]interface{}, 0, len(byTool))
	for _, s := range byTool {
		count := s["count"].(int)
		success := s["success_count"].(int)
		fail := s["fail_count"].(int)
		totalDur := s["total_duration_ms"].(int)
		avgDur := 0.0
		if count > 0 {
			avgDur = float64(totalDur) / float64(count)
		}
		s["avg_duration_ms"] = avgDur
		delete(s, "total_duration_ms")
		toolStats = append(toolStats, s)
		totalCalls += count
		successCount += success
		failCount += fail
		totalDurationMs += totalDur
	}
	avgDuration := 0.0
	if totalCalls > 0 {
		avgDuration = float64(totalDurationMs) / float64(totalCalls)
	}
	successRate := 0.0
	if totalCalls > 0 {
		successRate = float64(successCount) / float64(totalCalls) * 100
	}
	return map[string]interface{}{
		"total_calls": totalCalls, "success_count": successCount, "fail_count": failCount,
		"success_rate": successRate, "avg_duration_ms": avgDuration, "by_tool": toolStats,
	}
}