package datetime

import (
	"context"
	"fmt"
	"strings"
	"time"

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

type DatetimePlugin struct{ sdk.BasePlugin }

func (p *DatetimePlugin) Metadata() sdk.PluginMetadata {
	return sdk.PluginMetadata{
		Name: "datetime", DisplayName: "Date & Time", Version: "1.0.0",
		Description: "Date/time utilities: now, format, arithmetic, diff, timezone list",
		Category: "utility", Author: sdk.PluginAuthor{Name: "Cyrene Team"},
	}
}

func (p *DatetimePlugin) Tools() []sdk.Tool { return []sdk.Tool{&DatetimeTool{}} }

type DatetimeTool struct{ sdk.BaseTool }

func (t *DatetimeTool) Definition() sdk.ToolDefinition {
	return sdk.ToolDefinition{
		ID: "datetime", Name: "datetime", DisplayName: "Date & Time",
		Description: "Date/time utility. Get current time, format dates, date arithmetic, date diff, list timezones.",
		Category: "utility", Complexity: sdk.ComplexitySimple,
		Parameters: map[string]interface{}{
			"type": "object",
			"properties": map[string]interface{}{
				"action":   map[string]interface{}{"type": "string", "enum": []string{"now", "format", "add", "diff", "timezone_list"}},
				"format":   map[string]interface{}{"type": "string"},
				"timezone": map[string]interface{}{"type": "string"},
				"date":     map[string]interface{}{"type": "string"},
				"duration": map[string]interface{}{"type": "string"},
				"date2":    map[string]interface{}{"type": "string"},
			},
			"required": []string{"action"},
		},
	}
}

func (t *DatetimeTool) Validate(args map[string]interface{}) error {
	if _, ok := args["action"]; !ok {
		return fmt.Errorf("missing required parameter: action")
	}
	return nil
}

func (t *DatetimeTool) Execute(_ context.Context, args map[string]interface{}) (*sdk.ToolResult, error) {
	action, _ := args["action"].(string)
	tzStr, _ := args["timezone"].(string)
	loc, _ := parseLocation(tzStr)
	now := time.Now().In(loc)

	switch action {
	case "now":
		return &sdk.ToolResult{ToolName: "datetime", Success: true,
			Output: fmt.Sprintf("Current time: %s (unix: %d, zone: %s)", now.Format(time.RFC3339), now.Unix(), loc.String())}, nil

	case "format":
		dateStr, _ := args["date"].(string)
		format, _ := args["format"].(string)
		if format == "" {
			format = time.RFC3339
		}
		parsed, err := parseDate(dateStr, loc)
		if err != nil {
			return &sdk.ToolResult{ToolName: "datetime", Success: false, Error: err.Error()}, nil
		}
		return &sdk.ToolResult{ToolName: "datetime", Success: true,
			Output: fmt.Sprintf("Formatted: %s", parsed.Format(format))}, nil

	case "add":
		dateStr, _ := args["date"].(string)
		durStr, _ := args["duration"].(string)
		base := now
		if dateStr != "" {
			var err error
			base, err = parseDate(dateStr, loc)
			if err != nil {
				return &sdk.ToolResult{ToolName: "datetime", Success: false, Error: err.Error()}, nil
			}
		}
		result, err := addDuration(base, durStr)
		if err != nil {
			return &sdk.ToolResult{ToolName: "datetime", Success: false, Error: err.Error()}, nil
		}
		return &sdk.ToolResult{ToolName: "datetime", Success: true,
			Output: fmt.Sprintf("%s + %s = %s", base.Format(time.RFC3339), durStr, result.Format(time.RFC3339))}, nil

	case "diff":
		d1, _ := args["date"].(string)
		d2, _ := args["date2"].(string)
		t1, err := parseDate(d1, loc)
		if err != nil {
			return &sdk.ToolResult{ToolName: "datetime", Success: false, Error: err.Error()}, nil
		}
		t2, err := parseDate(d2, loc)
		if err != nil {
			return &sdk.ToolResult{ToolName: "datetime", Success: false, Error: err.Error()}, nil
		}
		diff := t2.Sub(t1)
		if diff < 0 {
			diff = -diff
		}
		days := int(diff.Hours()) / 24
		hours := int(diff.Hours()) % 24
		minutes := int(diff.Minutes()) % 60
		seconds := int(diff.Seconds()) % 60
		return &sdk.ToolResult{ToolName: "datetime", Success: true,
			Output: fmt.Sprintf("Difference: %d days, %d hours, %d minutes, %d seconds", days, hours, minutes, seconds)}, nil

	case "timezone_list":
		return &sdk.ToolResult{ToolName: "datetime", Success: true,
			Output: "Common timezones: UTC, Asia/Shanghai, Asia/Tokyo, Asia/Seoul, Asia/Singapore, Asia/Kolkata, Asia/Dubai, Europe/London, Europe/Paris, Europe/Moscow, America/New_York, America/Chicago, America/Los_Angeles, America/Sao_Paulo, Australia/Sydney, Pacific/Auckland, Africa/Cairo, Africa/Lagos"}, nil

	default:
		return &sdk.ToolResult{ToolName: "datetime", Success: false,
			Error: fmt.Sprintf("unknown action: %s", action)}, nil
	}
}

func parseLocation(tz string) (*time.Location, error) {
	if tz == "" {
		loc, err := time.LoadLocation("Asia/Shanghai")
		if err != nil {
			return time.UTC, nil
		}
		return loc, nil
	}
	return time.LoadLocation(tz)
}

func parseDate(s string, loc *time.Location) (time.Time, error) {
	formats := []string{time.RFC3339, "2006-01-02T15:04:05", "2006-01-02 15:04:05", "2006-01-02", "2006/01/02"}
	for _, f := range formats {
		if t, err := time.ParseInLocation(f, s, loc); err == nil {
			return t, nil
		}
	}
	return time.Time{}, fmt.Errorf("cannot parse date: %s", s)
}

func addDuration(t time.Time, durStr string) (time.Time, error) {
	durStr = strings.TrimSpace(durStr)
	if durStr == "" {
		return t, nil
	}
	// Handle months and years
	if strings.Contains(durStr, "M") || strings.Contains(durStr, "y") {
		months := 0
		years := 0
		if strings.Contains(durStr, "y") {
			fmt.Sscanf(durStr, "%dy", &years)
		}
		if strings.Contains(durStr, "M") {
			fmt.Sscanf(durStr, "%dM", &months)
		}
		return t.AddDate(years, months, 0), nil
	}
	d, err := time.ParseDuration(durStr)
	if err != nil {
		return t, fmt.Errorf("invalid duration: %s", durStr)
	}
	return t.Add(d), nil
}