package operation

import (
	"bytes"
	"fmt"
	"log"
	"os"
	"strings"
	txtTemplate "text/template"

	gopath "path"

	"github.com/aziis98/cabret"
	"github.com/aziis98/cabret/path"
)

func init() {
	registerType("target", &Target{})
}

type Target struct {
	PathTemplate string
}

func (op *Target) Configure(config map[string]any) error {
	if v, ok := config["target"]; ok {
		template, ok := v.(string)
		if !ok {
			return fmt.Errorf(`expected a path template but got "%v" of type %T`, v, v)
		}

		op.PathTemplate = template
		return nil
	}

	return fmt.Errorf(`invalid config for "target": %#v`, config)
}

func (op Target) ProcessItem(c cabret.Content) (*cabret.Content, error) {
	log.Printf(`[operation.Target] expanding pattern "%s"`, op.PathTemplate)

	target := op.PathTemplate

	if strings.Contains(target, "{{") {
		t, err := txtTemplate.New("path").Parse(target)
		if err != nil {
			return nil, err
		}

		var buf bytes.Buffer
		if err := t.Execute(&buf, c.Metadata); err != nil {
			return nil, err
		}

		target = buf.String()
	}

	if v, ok := c.Metadata[cabret.MatchResultKey]; ok {
		context, ok := v.(map[string]string)
		if !ok {
			return nil, fmt.Errorf(`invalid match result type %T`, c.Metadata[cabret.MatchResultKey])
		}

		target = path.RenderTemplate(target, context)
	}

	log.Printf(`[operation.Target] writing "%s"`, target)

	if err := os.MkdirAll(gopath.Dir(target), 0777); err != nil {
		return nil, err
	}
	if err := os.WriteFile(target, c.Data, 0666); err != nil {
		return nil, err
	}

	c.Metadata["Target"] = op.PathTemplate
	return &c, nil
}