package msg

import (
	"bytes"
	"encoding/json"
	"fmt"
	"strings"
	"text/template"
	"time"

	"github.com/crazy-max/diun/v4/internal/model"
	"github.com/microcosm-cc/bluemonday"
	"github.com/opencontainers/go-digest"
	"github.com/pkg/errors"
	"github.com/russross/blackfriday/v2"
)

// Client represents an active msg object
type Client struct {
	opts Options
}

// Options holds msg client object options
type Options struct {
	Meta          model.Meta
	Entry         model.NotifEntry
	TemplateTitle string
	TemplateBody  string
	TemplateFuncs template.FuncMap
}

// New initializes a new msg client
func New(opts Options) (*Client, error) {
	return &Client{
		opts,
	}, nil
}

// RenderMarkdown returns a notification message as markdown
func (c *Client) RenderMarkdown() (title []byte, body []byte, _ error) {
	var titleBuf bytes.Buffer
	titleTpl, err := template.New("title").Funcs(c.opts.TemplateFuncs).Parse(strings.TrimSuffix(strings.TrimSpace(c.opts.TemplateTitle), "\n"))
	if err != nil {
		return title, body, errors.Wrap(err, "cannot parse title template")
	}
	if err = titleTpl.Execute(&titleBuf, struct {
		Meta  model.Meta
		Entry model.NotifEntry
	}{
		Meta:  c.opts.Meta,
		Entry: c.opts.Entry,
	}); err != nil {
		return title, body, errors.Wrap(err, "cannot render notif title")
	}
	title = titleBuf.Bytes()

	var bodyBuf bytes.Buffer
	bodyTpl, err := template.New("body").Funcs(c.opts.TemplateFuncs).Parse(strings.TrimSuffix(strings.TrimSpace(c.opts.TemplateBody), "\n"))
	if err != nil {
		return title, body, errors.Wrap(err, "cannot parse body template")
	}
	if err = bodyTpl.Execute(&bodyBuf, struct {
		Meta  model.Meta
		Entry model.NotifEntry
	}{
		Meta:  c.opts.Meta,
		Entry: c.opts.Entry,
	}); err != nil {
		return title, body, errors.Wrap(err, "cannot render notif body")
	}
	body = bodyBuf.Bytes()

	return
}

// RenderHTML returns a notification message as html
func (c *Client) RenderHTML() (title []byte, body []byte, err error) {
	title, body, err = c.RenderMarkdown()
	if err != nil {
		return title, body, err
	}

	body = []byte(bluemonday.UGCPolicy().Sanitize(
		// Dirty way to remove wrapped <p></p> and newline
		// https://github.com/russross/blackfriday/issues/237
		strings.TrimRight(strings.TrimLeft(strings.TrimSpace(string(blackfriday.Run(body))), "<p>"), "</p>"),
	))
	return
}

// RenderJSON returns a notification message as JSON
func (c *Client) RenderJSON() ([]byte, error) {
	return json.Marshal(struct {
		Version  string            `json:"diun_version"`
		Hostname string            `json:"hostname"`
		Status   string            `json:"status"`
		Provider string            `json:"provider"`
		Image    string            `json:"image"`
		HubLink  string            `json:"hub_link"`
		MIMEType string            `json:"mime_type"`
		Digest   digest.Digest     `json:"digest"`
		Created  *time.Time        `json:"created"`
		Platform string            `json:"platform"`
		Metadata map[string]string `json:"metadata"`
	}{
		Version:  c.opts.Meta.Version,
		Hostname: c.opts.Meta.Hostname,
		Status:   string(c.opts.Entry.Status),
		Provider: c.opts.Entry.Provider,
		Image:    c.opts.Entry.Image.String(),
		HubLink:  c.opts.Entry.Image.HubLink,
		MIMEType: c.opts.Entry.Manifest.MIMEType,
		Digest:   c.opts.Entry.Manifest.Digest,
		Created:  c.opts.Entry.Manifest.Created,
		Platform: c.opts.Entry.Manifest.Platform,
		Metadata: c.opts.Entry.Metadata,
	})
}

// RenderEnv returns a notification message as environment variables
func (c *Client) RenderEnv() []string {
	var metadataEnvs []string
	for k, v := range c.opts.Entry.Metadata {
		metadataEnvs = append(metadataEnvs, fmt.Sprintf("DIUN_ENTRY_METADATA_%s=%s", strings.ToUpper(k), v))
	}
	return append([]string{
		fmt.Sprintf("DIUN_VERSION=%s", c.opts.Meta.Version),
		fmt.Sprintf("DIUN_HOSTNAME=%s", c.opts.Meta.Hostname),
		fmt.Sprintf("DIUN_ENTRY_STATUS=%s", string(c.opts.Entry.Status)),
		fmt.Sprintf("DIUN_ENTRY_PROVIDER=%s", c.opts.Entry.Provider),
		fmt.Sprintf("DIUN_ENTRY_IMAGE=%s", c.opts.Entry.Image.String()),
		fmt.Sprintf("DIUN_ENTRY_HUBLINK=%s", c.opts.Entry.Image.HubLink),
		fmt.Sprintf("DIUN_ENTRY_MIMETYPE=%s", c.opts.Entry.Manifest.MIMEType),
		fmt.Sprintf("DIUN_ENTRY_DIGEST=%s", c.opts.Entry.Manifest.Digest),
		fmt.Sprintf("DIUN_ENTRY_CREATED=%s", c.opts.Entry.Manifest.Created),
		fmt.Sprintf("DIUN_ENTRY_PLATFORM=%s", c.opts.Entry.Manifest.Platform),
	}, metadataEnvs...)
}