from django.contrib import admin
from django.contrib.admin import action
from django.utils.safestring import mark_safe
from . import models


class StateParameterInline(admin.StackedInline):
    model = models.StateParameter
    extra = 1


class ProcessNodeInline(admin.StackedInline):
    model = models.ProcessNode
    extra = 1
    autocomplete_fields = ('state',)
    ordering = ('order',)


@admin.register(models.State)
class StateAdmin(admin.ModelAdmin):
    list_display = (
        'id', 
        'name', 
        'description', 
        'created_at', 
        'updated_at',
        'parameter_overview',
    )
    search_fields = ('name', 'description')
    list_filter = ('created_at', 'updated_at', 'processes__name')
    inlines = [StateParameterInline]

    @admin.display(description='参数概览')
    def parameter_overview(self, obj: models.State):
        params = obj.parameters.all()
        if params:
            result = "<br>".join([f"{param.key}={param.value}" for param in params])
        else:
            result = "-"
        return mark_safe(result)


@admin.register(models.Process)
class ProcessAdmin(admin.ModelAdmin):
    list_display = (
        'id', 
        'name', 
        'node_count',
        'description', 
        'updated_at',
    )
    search_fields = ('name', 'description')
    list_filter = ('created_at', 'updated_at')
    inlines = [ProcessNodeInline]

    @admin.display(description='节点数量')
    def node_count(self, obj: models.Process):
        return obj.process_nodes.count()


class StateFlowRecordInline(admin.StackedInline):
    model = models.StateFlowRecord
    extra = 0
    fields = ('state', 'completed_at', 'completed_by', 'is_cancelled', 'cancelled_at')
    readonly_fields = ('completed_at', 'completed_by', 'cancelled_at')
    can_delete = False
    ordering = ('completed_at',)


@admin.register(models.BusinessObject)
class BusinessObjectAdmin(admin.ModelAdmin):
    list_display = (
        'id', 
        'name', 
        'process',
        'content_object_display',
        'current_state_display', 
        'progress',
        'params',
        'updated_at',
    )
    search_fields = ('name', 'description')
    list_filter = ('process', 'created_at', 'updated_at')
    actions = ['advance_to_next_state_action', 'reset_progress_action']
    autocomplete_fields = ('process',)
    inlines = [StateFlowRecordInline]
    fieldsets = [
        ('基本信息', {
            'fields': ['name', 'process', 'description']
        }),
        ('关联对象（可选）', {
            'fields': ['content_type', 'object_id'],
            'description': '可选择关联到实际的业务对象，如订单、工单等'
        }),
    ]

    @admin.display(description='关联对象')
    def content_object_display(self, obj: models.BusinessObject):
        """显示关联对象"""
        if obj.content_object:
            return f"{obj.content_type} #{obj.object_id}"
        return "-"
    
    @action(description='前进到下一个状态')
    def advance_to_next_state_action(self, request, queryset):
        from . import services
        success_count = 0
        messages = []
        
        for obj in queryset:
            success, message = services.advance_to_next_state(obj, request.user)
            if success:
                success_count += 1
            messages.append(f"{obj.name}: {message}")
        
        self.message_user(request, f'成功推进 {success_count}/{queryset.count()} 个业务对象。详情: {"; ".join(messages[:5])}')

    @action(description='重置进度')
    def reset_progress_action(self, request, queryset):
        from . import services
        for obj in queryset:
            services.reset_business_object_progress(obj)
        self.message_user(request, f'已重置 {queryset.count()} 个业务对象的进度。')

    @admin.display(description='当前状态', ordering='process')
    def current_state_display(self, obj: models.BusinessObject):
        from . import services
        current_state = obj.get_current_state()
        overall_status = services.get_overall_status(obj)
        
        if overall_status == 'not_started':
            return '未开始'
        elif overall_status == 'completed':
            return '已完成'
        elif current_state:
            return current_state.name
        return '-'

    @admin.display(description='进度')
    def progress(self, obj: models.BusinessObject):
        return f"{obj.get_progress_percentage():.1f}%"

    @admin.display(description='本步骤参数')
    def params(self, obj: models.BusinessObject):
        current_state = obj.get_current_state()
        if current_state:
            params = current_state.parameters.all()
            if params:
                return ", ".join([f"{param.key}={param.value}" for param in params])
        return "-"


@admin.register(models.StateFlowRecord)
class StateFlowRecordAdmin(admin.ModelAdmin):
    list_display = ('id', 'business_object', 'state', 'completed_at', 'completed_by', 'is_cancelled', 'cancelled_at')
    search_fields = ('business_object__name', 'state__name')
    list_filter = ('state', 'is_cancelled', 'completed_at', 'completed_by')
    readonly_fields = ('business_object', 'state', 'completed_at', 'completed_by', 'cancelled_at')
    fields = ('business_object', 'state', 'completed_at', 'completed_by', 'is_cancelled', 'cancelled_at')
    autocomplete_fields = ('business_object', 'state', 'completed_by')