package cabana

import (
	"fmt"
	"strings"

	"git.golem15.com/golem15/summercms/modules/pact"
	"git.golem15.com/golem15/summercms/modules/seaglass"
	"github.com/goccy/go-yaml/ast"
)

// richEditorType is the core HTML WYSIWYG field type (D-10).
const richEditorType = "richeditor"

// The phrase keys of the notices a richeditor save reports (backend::lang).
const (
	msgRichRemovedElements   = "backend::lang.richeditor.removed_elements"
	msgRichRemovedAttributes = "backend::lang.richeditor.removed_attributes"
	msgRichRemovedComments   = "backend::lang.richeditor.removed_comments"
	msgRichMarkupChanged     = "backend::lang.richeditor.markup_changed"
)

// richEditorKeys are the fields.yaml keys a richeditor field accepts: the
// common field keys plus size.
var richEditorKeys = map[string]bool{
	"label": true, "comment": true, "span": true, "type": true, "required": true,
	"tab": true, "context": true, "size": true, "default": true,
}

// compileRichEditorKeys refuses every key a richeditor field does not take.
func compileRichEditorKeys(typ string, values map[string]ast.Node) error {
	if typ != richEditorType {
		return nil
	}
	for key := range values {
		if !richEditorKeys[key] {
			return fmt.Errorf("%s is not valid on type: richeditor", key)
		}
	}
	return nil
}

// checkRichEditorValues refuses, before the save transaction, a submitted
// richeditor value that is neither a string nor null: it is a 422 on the
// field, never silently dropped.
func checkRichEditorValues(cc *CompiledController, body map[string]any, op string) error {
	if cc == nil || cc.Form == nil {
		return nil
	}
	for _, field := range cc.Form.Fields {
		if field.Type != richEditorType || !contextAllows(cc, field.Name, op) {
			continue
		}
		value, present := body[field.Name]
		if !present {
			continue
		}
		switch value.(type) {
		case nil, string:
		default:
			return &ValidationError{Details: fillTypeDetails(field.Name)}
		}
	}
	return nil
}

// sanitizeRichEditors runs every projected richeditor value through
// seaglass.SanitizeReport and writes the clean value back, so no richeditor
// value reaches Fill unsanitized. HTML the policy keeps whole is stored byte
// for byte; what it removed is returned as notices on the field.
func sanitizeRichEditors(cc *CompiledController, projected map[string]any) []pluginNotice {
	if cc == nil || cc.Form == nil {
		return nil
	}
	var notices []pluginNotice
	for _, field := range cc.Form.Fields {
		if field.Type != richEditorType {
			continue
		}
		key := fillKeyOf(cc, field.Name)
		value, present := projected[key]
		if !present {
			continue
		}
		text, ok := value.(string)
		if !ok {
			continue
		}
		clean, report := seaglass.SanitizeReport(text)
		projected[key] = clean
		for _, notice := range richEditorNotices(report) {
			notices = append(notices, pluginNotice{field: field.Name, notice: notice})
		}
	}
	return notices
}

// fillKeyOf is the fill key bound to a writable field name.
func fillKeyOf(cc *CompiledController, name string) string {
	for _, field := range cc.Writable {
		if field.Name == name {
			return field.FillKey
		}
	}
	return name
}

// richEditorNotices turns a removal report into admin notices: removed
// elements, removed attributes, removed comments, in that order and only when
// non-zero, and markup_changed when the policy changed the HTML in a way none
// of them describe.
func richEditorNotices(r seaglass.Removals) []pact.FormFieldNotice {
	var out []pact.FormFieldNotice
	if r.ElementCount > 0 {
		out = append(out, pact.FormFieldNotice{
			Message: msgRichRemovedElements,
			Params:  map[string]string{"names": strings.Join(r.Elements, ", ")},
			Count:   r.ElementCount,
		})
	}
	if r.AttributeCount > 0 {
		out = append(out, pact.FormFieldNotice{
			Message: msgRichRemovedAttributes,
			Params:  map[string]string{"names": strings.Join(r.Attributes, ", ")},
			Count:   r.AttributeCount,
		})
	}
	if r.Comments > 0 {
		out = append(out, pact.FormFieldNotice{Message: msgRichRemovedComments, Count: r.Comments})
	}
	if r.Changed && len(out) == 0 {
		out = append(out, pact.FormFieldNotice{Message: msgRichMarkupChanged})
	}
	return out
}