package builder

import (
	"fmt"

	"github.com/acaloiaro/frm"
	"github.com/acaloiaro/frm/types"
	"github.com/acaloiaro/frm/ui"
	"github.com/acaloiaro/frm/ui/collector"
	"github.com/acaloiaro/frm/ui/fields"
	"github.com/acaloiaro/frm/ui/selector"

	"github.com/google/uuid"
)

// Application DOM events
const (
	// FieldsFormEvent is the event triggered when any of a form's fields have been updated in the UI. When triggered,
	// the fields form pushes updates from the UI to the draft form on the backend.
	FieldsFormUpdateEvent = "fields-form-updated"
	// FormSettingsEvent is the event triggered when any of a form's settings have been updated in the UI. When triggered,
	// the fields form pushes updates from the UI to the draft form on the backend.
	FormSettingsUpdateEvent = "form-settings-updated"
	// LogicConfiguratorTargetFieldSelected is the event triggered when a form field is selected as a the target for field logic
	LogicConfiguratorTargetFieldSelected = "logic-configurator-target-field-selected"
)

// Logic field group form field names
const (
	// FieldLogicChosenFieldID is the name of a HTML form field. The value of the form field with this name represents the field that was chosen as the target for field-specific logic.
	//
	// TODO: provide an example
	FieldLogicTargetFieldID = "target_field_id"
	// FieldLogicChosenField is the name of a HTML form field. The value of the form field represents the boolean comparator to be used to evaluate the chosen field against its field value.
	//
	// TODO: provide an example
	FieldLogicComparator = "comparator"
	// FieldLogicChosenFieldValue is the name of a HTML Form field. The value of the form field represents the value that the target field's value is compared against when deciding whether or not to display a field in the UI.
	//
	// TODO: provide an example
	FieldLogicTargetFieldValue = "target_field_value"
)

// Field groups within the the form field configuration screen
const (
	FieldGroupLogic = "logic"
)

// Builder is the primary form builder UI, surrounded by the app chrome
templ Builder(form frm.Form) {
	@ui.App("Form builder") {
		<section id="app-container h-2/3 max-h-1/3">
			@FormBuilderNav(form)
			<section id="builder-main" class="flex pt-20">
				<!-- Left column -->
				@builderColumnLeft(form)
				<!-- Middle Column -->
				@collector.FormPreview(collector.ViewerArgs{Preview: true, Form: form})
				<!-- Right Column -->
				@builderColumnRight(form)
			</section>
		</section>
	}
}

// FormBuilderNavTitle renders the title of the form in the nav bar. This is a separate template so that the title can be updated when settings change, without updating, and losing the state of, the rest of the nav bar
templ FormBuilderNavTitle(form frm.Form) {
	<div id="form-builder-nav-title" data-hx-swap-oob="true" class="flex-grow flex justify-center">
		<h3 tabindex="0" class="rounded px-2 cursor-pointer relative font-medium py-1 text-2xl w-2/3 text-center text-gray-500 truncate form-editor-title" style="height: auto;" id="form-editor-title">
			{ form.Name }
		</h3>
	</div>
}

// FormBuilderNav is the top-of-the-page navigation bar
templ FormBuilderNav(form frm.Form) {
	<div id="form-builder-nav" data-hx-swap-oob="true" class="fixed w-full p-2 flex gap-x-2 items-center bg-white z-50">
		<div id="form-editor-navbar-tabs">
			<div role="tablist" aria-orientation="horizontal" class="tabs tabs-boxed bg-gray-50 dark:bg-gray-800 rounded-lg p-1 h-auto grid grid-cols-2 items-center gap-x-1.5 px-2">
				@ui.MutedButton(ui.ButtonArgs{Label: "Build", Classes: []string{"cursor-pointer tab-active [--fallback-p:white] [--fallback-pc:black] place-self-center"}}, templ.Attributes{
					"role":     "tab",
					"tabindex": 0,
					"_":        "on click take .tab-active from .tab-active then add .hidden to .active-section then take .active-section for #form-fields then remove .hidden from #form-fields",
				})
				@ui.MutedButton(ui.ButtonArgs{Label: "Settings", Classes: []string{"cursor-pointer [--fallback-p:white] [--fallback-pc:black] place-self-center"}}, templ.Attributes{
					"role":     "tab",
					"tabindex": 2,
					"_":        "on click take .tab-active from .tab-active then add .hidden to .active-section take .active-section for #settings-main then remove .hidden from #settings-main",
				})
			</div>
		</div>
		@FormBuilderNavTitle(form)
		<div class="flex items-stretch gap-x-2">
			<div class="inline-flex items-center relative">
				<a href="#" class="text-sm p-2 hover:bg-gray-100 cursor-pointer rounded-lg text-gray-500 hover:text-gray-800 cursor-pointer"><span class="iconify i-heroicons:question-mark-circle w-5 h-5" aria-hidden="true"></span></a><!---->
			</div>
			<div class="relative inline-flex">
				<button
					type="button"
					class="focus:outline-none disabled:cursor-not-allowed disabled:opacity-75 aria-disabled:cursor-not-allowed aria-disabled:opacity-75 flex-shrink-0 font-medium rounded-md text-sm gap-x-1.5 shadow-sm text-white dark:text-gray-900 bg-primary-500 hover:bg-primary-600 disabled:bg-primary-500 aria-disabled:bg-primary-500 dark:bg-primary-400 dark:hover:bg-primary-500 dark:disabled:bg-primary-400 dark:aria-disabled:bg-primary-400 focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-primary-500 dark:focus-visible:outline-primary-400 inline-flex items-center px-8 md:px-4 py-2"
					data-hx-put={ ui.FormUrl[string](ctx, form, "/publish") }
					data-hx-trigger="click"
					data-hx-swap="none"
				>
					<!---->
					<svg class="w-4 h-4 text-white inline mr-1 -mt-1" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg"><path d="M17 21V13H7V21M7 3V8H15M19 21H5C4.46957 21 3.96086 20.7893 3.58579 20.4142C3.21071 20.0391 3 19.5304 3 19V5C3 4.46957 3.21071 3.96086 3.58579 3.58579C3.96086 3.21071 4.46957 3 5 3H16L21 8V19C21 19.5304 20.7893 20.0391 20.4142 20.4142C20.0391 20.7893 19.5304 21 19 21Z" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg> Save Form <!---->
				</button><!---->
			</div>
		</div>
	</div>
}

// FormSettings is the UI for configuring form-level settings.
templ FormSettings(form frm.Form) {
	<div id="settings-main" class="hidden">
		<form
			id="settings-form"
			data-hx-put={ ui.FormUrl[string](ctx, form, "/settings") }
			data-hx-trigger={ FormSettingsUpdateEvent }
			data-hx-swap-oob="true"
		>
			<div class="pt-3">
				<label for="form-name-field" class="pr-1">
					Form name
				</label>
				@fields.RequiredFieldIndicator()
			</div>
			<input
				id="form-name-field"
				name="name"
				type="text"
				class="w-full rounded-md"
				value={ form.Name }
				placeholder="Enter a good name for your form"
				autocomplete="off"
				_={ fmt.Sprintf("on keyup debounced at 600ms trigger '%s'", FormSettingsUpdateEvent) }
			/>
		</form>
	</div>
}

// builderColumnLeft is the left-hand panel of the form builder UI
templ builderColumnLeft(form frm.Form) {
	<section id="builder-main-left-col" class="flex flex-col gap-3 w-1/4 min-w-max h-full p-4 text-gray-800 rounded-md">
		@FormFields(form)
		@FormSettings(form)
	</section>
}

// FormFields lists a form's fields as a sortable list, that when re-sorted, updates the fields' sort order in the form
templ FormFields(form frm.Form) {
	<div id="form-fields" class="active-section">
		@FormFieldsForm(form)
	</div>
}

// FormFieldsForm is the list of fields on the left-hand side of the screen that displays a sorted list of form fields
templ FormFieldsForm(form frm.Form) {
	<div id="form-fields-form" data-hx-swap-oob="true" class="flex flex-col gap-3 w-full">
		@ui.Button(ui.ButtonArgs{
			Label:   "Add field",
			Classes: []string{"flex-grow", "justify-center", "uppercase"},
		}, templ.Attributes{
			"_": "on click toggle .hidden on .active-configurator then take .active-configurator from .active-configurator for #configure-add-field then remove .hidden from #configure-add-field",
		}) {
			@ui.HeroIcon("solid", "plus")
		}
		<div class="w-full border-b pb-2"></div>
		<form
			data-hx-put={ ui.FormUrl[string](ctx, form, "/fields/order") }
			data-hx-trigger="end"
			data-hx-swap="outerHTML"
			data-hx-target="#form-fields-form"
			data-hx-indidcator="#ind"
		>
			<div class="flex flex-col gap-1 sortable">
				for _, field := range fields.SortFields(form.Fields) {
					<div class="mx-auto w-full border-gray-300 transition-colors bg-gray-50 hover:bg-gray-100 rounded-lg sortme max-w-84 field-row">
						<input name="order" type="hidden" value={ field.ID.String() }/>
						<div class="group flex items-center gap-x-0.5 py-1.5 pr-1">
							<!-- field item -->
							<a
								href="#"
								class="w-full"
								_={ fmt.Sprintf("on click add .hidden to .active-configurator then take .active-configurator from .active-configurator for #configure-%s then remove .hidden from #configure-%s", field.ID.String(), field.ID.String()) }
							>
								<div class="flex flex-col cursor-pointer">
									<div tabindex="0" class="dark:hover:bg-gray-800 rounded px-2 relative text-gray-700 max-w-72 min-h-6" style="height: auto;">
										<p class="w-full cursor-pointer truncate">{ field.Label }</p>
									</div>
								</div>
							</a>
							if field.Required {
								<div class="relative inline-flex">
									<button class="hidden rounded p-0.5 transition-colors hover:bg-nt-blue-lighter items-center px-1 justify-center md:flex text-red-500">
										<div class="h-6 text-center text-2xl font-bold text-inherit -mt-0.5">* </div>
									</button>
								</div>
							}
							<div class="cursor-move">
								@ui.HeroIcon("solid", "bars-3")
							</div>
						</div>
					</div>
				}
			</div>
		</form>
	</div>
}

// builerColumnRight is the right-hand panel of the form build UI, used for adding and configuring fields
templ builderColumnRight(form frm.Form) {
	<section id="builder-main-right-col" class="w-1/4 h-full p-4 text-gray-800 rounded-md">
		<div id="configure-add-field" class="hidden">
			<div class="h-12 border-b text-lg text-center uppercase">Add field</div>
			for i, fieldType := range types.FormFieldTypeValues() {
				<div class="group flex items-center my-1.5 pr-1">
					<a href="#" class="w-full">
						<div class="flex flex-col">
							<div
								tabindex={ fmt.Sprint(i) }
								class="hover:bg-gray-50 dark:hover:bg-gray-800 rounded cursor-pointer relative truncate text-gray-700 min-w-16 min-h-6"
								style="height: auto;"
								data-hx-post={ ui.FormUrl[string](ctx, form, "/fields") }
								data-hx-trigger="click"
								data-hx-vals={ fmt.Sprintf(`{"field_type": "%s"}`, fieldType) }
								data-hx-swap="none"
							>
								@fields.FormFieldTypeLabel(types.FormFieldType(fieldType))
							</div>
						</div>
					</a>
				</div>
			}
		</div>
		@FormFieldConfigurator(form)
	</section>
}

// FormFieldConfigurator is the view on the right-hand side of the screen for configuring individual fields
templ FormFieldConfigurator(form frm.Form) {
	<form
		id="fields-form"
		data-hx-put={ ui.FormUrl[string](ctx, form, "/fields") }
		data-hx-trigger={ FieldsFormUpdateEvent }
		data-hx-swap="none"
		data-hx-swap-oob="true"
	>
		for _, field := range fields.SortFields(form.Fields) {
			<div id={ fmt.Sprintf("configure-%s", field.ID.String()) } class="hidden">
				<div class="mx-auto w-full border-gray-300 transition-colors pb-3">
					@fields.FormFieldTypeLabel(types.FormFieldType(field.Type))
				</div>
				<div id={ fmt.Sprintf("configurator-tabs-%s", field.ID.String()) } class="border-b pb-4">
					<div role="tablist" aria-orientation="horizontal" class="tabs tabs-boxed bg-gray-50 dark:bg-gray-800 rounded-lg h-auto flex gap-2">
						@ui.MutedButton(ui.ButtonArgs{Label: "Settings", Classes: []string{"cursor-pointer tab-active [--fallback-p:white] [--fallback-pc:black] place-self-center w-1/2"}}, templ.Attributes{
							"role":     "tab",
							"tabindex": 1,
							"_":        fmt.Sprintf("on click take .tab-active from <#configurator-tabs-%s .tab-active/> then add .hidden to #field-%s-logic then take .active-configurator-section from #field-%s-logic for #%s then remove .hidden from #%s", field.ID.String(), field.ID.String(), field.ID.String(), fmt.Sprintf("field-%s-settings", field.ID.String()), fmt.Sprintf("field-%s-settings", field.ID.String())),
						})
						@ui.MutedButton(ui.ButtonArgs{Label: "Logic", Classes: []string{"cursor-pointer [--fallback-p:white] [--fallback-pc:black] place-self-center w-1/2"}}, templ.Attributes{
							"role":     "tab",
							"tabindex": 2,
							"_":        fmt.Sprintf("on click take .tab-active from <#configurator-tabs-%s .tab-active/> then add .hidden to #field-%s-settings then take .active-configurator-section from #field-%s-settings for #%s then remove .hidden from #%s", field.ID.String(), field.ID.String(), field.ID.String(), fmt.Sprintf("field-%s-logic", field.ID.String()), fmt.Sprintf("field-%s-logic", field.ID.String())),
						})
					</div>
				</div>
				<!-- Form fields settings configurations -->
				@fieldSettingsConfiguration(form, field)
				<!-- Form fields logic configurations -->
				@fieldLogicConfiguration(form, field)
			</div>
		}
	</form>
}

// fieldSettingsConfiguration configures the settings for a specific field
// FIELD_TYPES: field types may be added/modified/removed below
templ fieldSettingsConfiguration(form frm.Form, field types.FormField) {
	<div id={ fmt.Sprintf("field-%s-settings", field.ID.String()) } class="active-configurator-section">
		<input name={ fields.FieldName(field, "", "required") } type="hidden" value={ fmt.Sprint(field.Required) }/>
		<input name={ fields.FieldName(field, "", "hidden") } type="hidden" value={ fmt.Sprint(field.Hidden) }/>
		<input name={ fields.FieldName(field, "", "field_type") } type="hidden" value={ fmt.Sprint(field.Type) }/>
		<div class="pt-3">
			<label for={ fields.FieldName(field, "", "label") } class="pr-1">
				Field label
			</label>
			@fields.RequiredFieldIndicator()
		</div>
		<input
			id={ fields.FieldName(field, "", "label") }
			name={ fields.FieldName(field, "", "label") }
			type="text"
			class="w-full rounded-md"
			value={ field.Label }
			autocomplete="off"
			_={ fmt.Sprintf("on keyup debounced at 600ms trigger '%s'", FieldsFormUpdateEvent) }
		/>
		switch field.Type {
			case types.FormFieldTypeTextSingle, types.FormFieldTypeTextMultiple:
				<div class="pt-3">
					<label for={ fields.FieldName(field, "", "placeholder") } class="pr-1">
						Placeholder
					</label>
				</div>
				<input
					id={ fields.FieldName(field, "", "placeholder") }
					name={ fields.FieldName(field, "", "placeholder") }
					type="text"
					class="w-full rounded-md"
					value={ field.Placeholder }
					autocomplete="off"
					_={ fmt.Sprintf("on keyup debounced at 600ms trigger '%s'", FieldsFormUpdateEvent) }
				/>
			case types.FormFieldTypeMultiSelect, types.FormFieldTypeSingleSelect, types.FormFieldTypeSingleChoice:
				<div class="pt-3">
					<label for={ fields.FieldName(field, "", "options") } class="pr-1">
						Options
					</label>
				</div>
				@selector.Selector(selector.SelectArgs{
					ID:                   fields.FieldName(field, "", "options"),
					Name:                 fields.FieldName(field, "", "options"),
					Placeholder:          "Add, remove, or create new options",
					Multiple:             true,
					EditItems:            true,
					Options:              fields.ToSelectorOpts(field.Options, true),
					SelectionChangeEvent: FieldsFormUpdateEvent,
				})
				if field.Type == types.FormFieldTypeSingleChoice {
					<div class="pt-3">
						<label for={ fields.FieldName(field, "", "option_labels") } class="pr-1">
							Option labels
						</label>
					</div>
					@selector.Selector(selector.SelectArgs{
						ID:                   fields.FieldName(field, "", "option_labels"),
						Name:                 fields.FieldName(field, "", "option_labels"),
						Placeholder:          "Create labels for your options",
						Multiple:             true,
						EditItems:            true,
						Options:              fields.ToSelectorOptsStr(field.OptionLabels, true),
						SelectionChangeEvent: FieldsFormUpdateEvent,
					})
				}
		}
		<div class="pt-3">
			<label for={ fields.FieldName(field, "", "required") } class="pr-1">
				Required
			</label>
		</div>
		<input
			id={ fields.FieldName(field, "", "required") }
			name={ fields.FieldName(field, "", "required") }
			type="checkbox"
			class="checkbox checkbox-primary"
			if field.Required {
				checked
			}
			_={ fmt.Sprintf(`
						on click 
						if my.checked 
							set <input[name='%s']/>'s checked to false 
						end  
						then trigger '%s'`, 
						fields.FieldName(field, "","hidden"), FieldsFormUpdateEvent) }
		/>
		<div class="pt-3">
			<label for={ fields.FieldName(field, "", "hidden") } class="pr-1">
				Hidden
			</label>
		</div>
		<input
			id={ fields.FieldName(field, "", "hidden") }
			name={ fields.FieldName(field, "", "hidden") }
			type="checkbox"
			class="checkbox checkbox-primary"
			if field.Hidden {
				checked
			}
			_={ fmt.Sprintf(`
						on click 
						if my.checked 
							set <input[name='%s']/>'s checked to false 
						end  
						then trigger '%s'`, 
						fields.FieldName(field, "","required"), FieldsFormUpdateEvent) }
		/>
		<div class="py-3 divide-y">
			<label for="delete-field" class="pr-1">
				Danger zone
			</label>
		</div>
		@ui.Button(ui.ButtonArgs{Type: "button", Label: "Delete field"}, templ.Attributes{
			"data-hx-delete":  ui.FormUrl[string](ctx, form, fmt.Sprintf("/fields/%s", field.ID)),
			"data-hx-trigger": "click",
			"data-hx-confirm": "Are you sure?",
		})
	</div>
}

templ fieldLogicConfiguration(form frm.Form, field types.FormField) {
	<div id={ fmt.Sprintf("field-%s-logic", field.ID.String()) } class="flex flex-col gap-5 hidden">
		<div>
			<div
				data-hx-get={ frm.BuilderPathFormField(ctx, form.ID, field.ID.String(), "/logic/choices") }
				data-hx-trigger={ FieldsFormUpdateEvent }
				data-hx-swap="innerHTML"
				data-hx-target={ fmt.Sprintf("#logic-field-value-chooser-%s", field.ID.String()) }
				data-hx-on:htmx:config-request="event.detail.parameters['id'] = event.detail.triggeringEvent.detail.value"
			>
				@selector.Selector(selector.SelectArgs{
					ID:                   fmt.Sprintf("field-%s-logic-config-field-chooser", field.ID.String()),
					Name:                 fields.FieldName(field, FieldGroupLogic, FieldLogicTargetFieldID),
					Placeholder:          "Choose a field",
					Options:              fields.FieldsAsSelectorOptions(form, field.ID),
					SearchDisabled:       true,
					SelectionChangeEvent: FieldsFormUpdateEvent,
				})
			</div>
		</div>
		<div>
			@selector.Selector(selector.SelectArgs{
				ID:                   fmt.Sprintf("field-%s-logic-config-condition-chooser", field.ID.String()),
				Name:                 fields.FieldName(field, FieldGroupLogic, FieldLogicComparator),
				Placeholder:          "Choose a condition",
				Options:              comparatorOptionsFor(field),
				SearchDisabled:       true,
				SelectionChangeEvent: FieldsFormUpdateEvent,
			})
		</div>
		<div>
			<div
				id={ fmt.Sprintf("logic-field-value-chooser-%s", field.ID.String()) }
			>
				if field.Logic != nil && field.Logic.TargetFieldID != uuid.Nil {
					@LogicConfiguratorStepThree(form, field, form.Fields[field.Logic.TargetFieldID.String()])
				}
			</div>
		</div>
		<div>
			<p class="pb-3">Choose an action</p>
			<input
				id={ fmt.Sprintf("%s-logic-action", field.ID.String()) }
				type="checkbox"
				class="checkbox"
				name={ fields.FieldName(field, FieldGroupLogic, types.FieldLogicTriggerShow.String()) }
				if field.Logic != nil && field.Logic.TriggerActions.Contains(types.FieldLogicTriggerShow) {
					checked
				}
				_={ fmt.Sprintf(`
						on click 
						trigger '%s'`, 
						FieldsFormUpdateEvent) }
			/>
			<label for={ fmt.Sprintf("%s-logic-action", field.ID.String()) }>Show this field</label>
		</div>
	</div>
}

// comparatorOptionsFor returns the comparators available for a logic field given its Type
func comparatorOptionsFor(field types.FormField) (options selector.FieldOptions) {
	switch field.Type {
	default:
		options = selector.FieldOptions{
			selector.Option{
				Value:    fmt.Sprint(types.FieldLogicComparatorContains),
				Label:    "Contains",
				Selected: field.Logic != nil && field.Logic.TriggerComparator == types.FieldLogicComparatorContains,
			},
			selector.Option{
				Value:    fmt.Sprint(types.FieldLogicComparatorEqual),
				Label:    "Equal to =",
				Selected: field.Logic != nil && field.Logic.TriggerComparator == types.FieldLogicComparatorEqual,
			},
			selector.Option{
				Value:    fmt.Sprint(types.FieldLogicComparatorNot),
				Label:    "NOT",
				Selected: field.Logic != nil && field.Logic.TriggerComparator == types.FieldLogicComparatorNot,
			},
		}
	}

	return
}

// LogicConfiguratorStepThree returns HTML input elments appropriate for choosing values for `targetField` in the logic configurator.
//
// field: the field being configured
// targetField: the target field chosen as the logic target
templ LogicConfiguratorStepThree(form frm.Form, field types.FormField, targetField types.FormField) {
	switch targetField.Type {
		case types.FormFieldTypeMultiSelect, types.FormFieldTypeSingleSelect, types.FormFieldTypeSingleChoice:
			@selector.Selector(selector.SelectArgs{
				ID:                   fmt.Sprintf("%s-logic-chosen-field-value", field.ID.String()),
				Label:                "",
				Name:                 fields.FieldName(field, FieldGroupLogic, FieldLogicTargetFieldValue),
				Options:              ui.FieldOptionsAsSelectorOptions(form, targetField),
				Placeholder:          "Choose a value",
				SelectionChangeEvent: FieldsFormUpdateEvent,
			})
		case types.FormFieldTypeTextSingle, types.FormFieldTypeTextMultiple:
			<input
				id={ fmt.Sprintf("%s-logic-chosen-field-value", field.ID.String()) }
				name={ fields.FieldName(field, FieldGroupLogic, FieldLogicTargetFieldValue) }
				type="text"
				class="bg-gray-50"
				placeholder="Enter a value"
				if field.Logic != nil && len(field.Logic.TriggerValues) > 0 {
					value={ field.Logic.TriggerValues[0] }
				}
				_={ fmt.Sprintf("on keyup debounced at 600ms trigger '%s'", FieldsFormUpdateEvent) }
			/>
	}
}