package main

import (
	"fmt"
	"os"
	"path"
	"text/template"
	"time"

	"github.com/google/shlex"
	"github.com/pelletier/go-toml"
)

// Site represents a site.
type Site struct {
	Title      string                 `toml:"title"`
	Tasks      []*Task                `toml:"tasks"`
	Params     map[string]interface{} `toml:"params"`
	Permalinks map[string]string      `toml:"permalinks"`
	Generated  time.Time              `toml:"-"`
	Root       *Page                  `toml:"-"`
	permalinks map[string]*template.Template
	templates  Templates
}

// Task represents a site build task.
type Task struct {
	Name        string            `toml:"name"`
	Input       []string          `toml:"input"`
	OutputExt   string            `toml:"output"`
	TemplateExt string            `toml:"template"`
	Preprocess  map[string]string `toml:"preprocess"`
	Postprocess string            `toml:"postprocess"`
	StaticDir   string            `toml:"static_dir"`
	OutputDir   string            `toml:"output_dir"`
	URL         string            `toml:"url"`
	UglyURLs    bool              `toml:"ugly_urls"`
	Feeds       []Feed            `toml:"feeds"`
	preprocess  map[string][]string
	postprocess []string
	feeds       map[string][]Feed
}

type Feed struct {
	InputDir string `toml:"input_dir"`
	Title    string `toml:"title"`
	Template string `toml:"template"`
	Output   string `toml:"output"`
}

func (t *Task) Match(ext string) bool {
	for i := range t.Input {
		if t.Input[i] == ext {
			return true
		}
	}
	return false
}

// LoadSite loads the site with the given configuration file.
func LoadSite(config string) (*Site, error) {
	f, err := os.Open(config)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	site := &Site{
		Generated: time.Now(),
	}
	if err := toml.NewDecoder(f).Decode(site); err != nil {
		return nil, err
	}

	funcs := site.funcs()

	// Parse permalinks
	site.permalinks = map[string]*template.Template{}
	for path := range site.Permalinks {
		t := template.New(fmt.Sprintf("permalink %q", path)).Funcs(funcs)
		_, err := t.Parse(site.Permalinks[path])
		if err != nil {
			return nil, err
		}
		site.permalinks[path] = t
	}

	// Load templates
	templateExts := []string{}
	for _, task := range site.Tasks {
		if task.TemplateExt != "" {
			templateExts = append(templateExts, task.TemplateExt)
		}
	}
	site.templates.Funcs(funcs)
	if err := site.templates.Load("templates", templateExts); err != nil {
		return nil, err
	}

	for _, task := range site.Tasks {
		// Populate feeds
		task.feeds = map[string][]Feed{}
		for _, feed := range task.Feeds {
			dir := path.Clean(feed.InputDir)
			task.feeds[dir] = append(task.feeds[dir], feed)
		}

		// Parse commands
		task.preprocess = map[string][]string{}
		for path := range task.Preprocess {
			preprocess, err := shlex.Split(task.Preprocess[path])
			if err != nil {
				return nil, err
			}
			task.preprocess[path] = preprocess
		}
		if task.Postprocess != "" {
			postprocess, err := shlex.Split(task.Postprocess)
			if err != nil {
				return nil, err
			}
			task.postprocess = postprocess
		}
	}

	return site, nil
}

func (s *Site) page(path string) *Page {
	return s.Root.getPage(path)
}