package routes

import (
	"bytes"
	"fmt"
	"io"
	"log"
	"path/filepath"
	"strings"

	"alin.ovh/elgit/git"
	"alin.ovh/elgit/templates"
	"github.com/microcosm-cc/bluemonday"
	"github.com/russross/blackfriday/v2"
	"github.com/savsgio/atreugo/v11"
)

func (d *deps) WriteError(rc *atreugo.RequestCtx, err error, i int) error {
	rc.SetStatusCode(i)
	data := templates.PageData{
		Meta: d.c.Meta,
		Error: &templates.Error{
			Code:    i,
			Message: err.Error(),
		},
	}
	if err := templates.ErrorPage(data).Render(rc); err != nil {
		log.Printf("error template: %s", err)

		return err
	}

	return nil
}

func (d *deps) listFiles(files []git.NiceTree, data map[string]any, rc *atreugo.RequestCtx) error {
	pageData := templates.PageData{
		Meta:        d.c.Meta,
		DisplayName: data["displayname"].(string),
		Name:        data["name"].(string),
		Ref:         data["ref"].(string),
		Description: data["desc"].(string),
		Parent:      "",
	}

	if parent, ok := data["parent"]; ok && parent != nil {
		pageData.Parent = parent.(string)
	}

	readme := ""
	if readmeContent, ok := data["readme"]; ok && readmeContent != nil {
		readme = readmeContent.(string)
	}

	dotdot := ""
	if dotdotPath, ok := data["dotdot"]; ok && dotdotPath != nil {
		dotdot = dotdotPath.(string)
	}

	return templates.TreePage(pageData, files, readme, dotdot).Render(rc)
}

func countLines(r io.Reader) (int, error) {
	buf := make([]byte, 32*1024)
	bufLen := 0
	count := 0
	nl := []byte{'\n'}

	for {
		c, err := r.Read(buf)
		if c > 0 {
			bufLen += c
		}
		count += bytes.Count(buf[:c], nl)

		switch {
		case err == io.EOF:
			/* handle last line not having a newline at the end */
			if bufLen >= 1 && buf[(bufLen-1)%(32*1024)] != '\n' {
				count++
			}

			return count, nil
		case err != nil:
			return 0, err
		}
	}
}

func (d *deps) showFile(content string, data map[string]any, rc *atreugo.RequestCtx) error {
	var renderedContent string
	if len(content) > 0 {
		switch filepath.Ext(data["path"].(string)) {
		case ".md":
			unsafe := blackfriday.Run(
				[]byte(content),
				blackfriday.WithExtensions(blackfriday.CommonExtensions),
			)
			html := bluemonday.UGCPolicy().SanitizeBytes(unsafe)
			renderedContent = string(html)
		default:
			safe := bluemonday.UGCPolicy().SanitizeBytes([]byte(content))
			renderedContent = fmt.Sprintf(`<pre>%s</pre>`, safe)
		}
	}

	lc, err := countLines(strings.NewReader(content))
	if err != nil {
		// Non-fatal, we'll just skip showing line numbers in the template.
		log.Printf("counting lines: %s", err)
	}

	lines := make([]int, lc)
	if lc > 0 {
		for i := range lines {
			lines[i] = i + 1
		}
	}

	pageData := templates.PageData{
		Meta:            d.c.Meta,
		DisplayName:     getDisplayName(data["name"].(string)),
		LineCount:       lines,
		Content:         content,
		RenderedContent: renderedContent,
		Name:            data["name"].(string),
		Ref:             data["ref"].(string),
		Description:     data["desc"].(string),
		Path:            data["path"].(string),
	}

	return templates.FilePage(pageData).Render(rc)
}