package main

import (
	"context"
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"

	"gitea.ssig33.com/ssig33/esacli/esa"
)

const usage = `esacli - esa.io API CLI

Usage:
  esacli <command> [options]

Commands:
  get      Fetch a single post
  search   Search posts
  create   Create a new post
  update   Update an existing post
  help     Show this help

Environment variables:
  ESA_TOKEN  esa.io API access token (required)
  ESA_TEAM   esa.io team name (required)

Run "esacli <command> -h" for command-specific options.
`

func main() {
	if err := run(os.Args[1:], os.Stdout, os.Stderr); err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		os.Exit(1)
	}
}

func run(args []string, stdout, stderr io.Writer) error {
	if len(args) == 0 {
		fmt.Fprint(stderr, usage)
		return errors.New("no command specified")
	}

	cmd := args[0]
	rest := args[1:]

	switch cmd {
	case "help", "-h", "--help":
		fmt.Fprint(stdout, usage)
		return nil
	case "get":
		return runGet(rest, stdout)
	case "search":
		return runSearch(rest, stdout)
	case "create":
		return runCreate(rest, stdout)
	case "update":
		return runUpdate(rest, stdout)
	default:
		fmt.Fprint(stderr, usage)
		return fmt.Errorf("unknown command: %s", cmd)
	}
}

func newClient() (*esa.Client, error) {
	token := os.Getenv("ESA_TOKEN")
	if token == "" {
		return nil, errors.New("ESA_TOKEN is not set")
	}
	team := os.Getenv("ESA_TEAM")
	if team == "" {
		return nil, errors.New("ESA_TEAM is not set")
	}
	c := esa.NewClient(team, token)
	if base := os.Getenv("ESA_BASE_URL"); base != "" {
		c.BaseURL = base
	}
	return c, nil
}

func runGet(args []string, stdout io.Writer) error {
	fs := flag.NewFlagSet("get", flag.ContinueOnError)
	number := fs.Int("number", 0, "post number (required)")
	bodyOnly := fs.Bool("body", false, "print only body_md instead of JSON")
	if err := fs.Parse(args); err != nil {
		return err
	}
	if *number <= 0 {
		return errors.New("get: -number is required")
	}
	c, err := newClient()
	if err != nil {
		return err
	}
	post, err := c.GetPost(context.Background(), *number)
	if err != nil {
		return err
	}
	if *bodyOnly {
		fmt.Fprint(stdout, post.BodyMD)
		return nil
	}
	return printJSON(stdout, post)
}

func runSearch(args []string, stdout io.Writer) error {
	fs := flag.NewFlagSet("search", flag.ContinueOnError)
	query := fs.String("q", "", "search query")
	page := fs.Int("page", 0, "page number")
	perPage := fs.Int("per-page", 0, "results per page (max 100)")
	sort := fs.String("sort", "", "sort field (updated, created, number, stars, watches, comments, best_match)")
	order := fs.String("order", "", "order (desc, asc)")
	if err := fs.Parse(args); err != nil {
		return err
	}
	c, err := newClient()
	if err != nil {
		return err
	}
	resp, err := c.SearchPosts(context.Background(), esa.SearchOptions{
		Query:   *query,
		Page:    *page,
		PerPage: *perPage,
		Sort:    *sort,
		Order:   *order,
	})
	if err != nil {
		return err
	}
	return printJSON(stdout, resp)
}

func runCreate(args []string, stdout io.Writer) error {
	fs := flag.NewFlagSet("create", flag.ContinueOnError)
	name := fs.String("name", "", "post title (required)")
	bodyFile := fs.String("body-file", "", "path to file containing body_md ('-' for stdin)")
	body := fs.String("body", "", "body_md (use -body-file for longer content)")
	tagsCSV := fs.String("tags", "", "comma-separated tags")
	category := fs.String("category", "", "category")
	wip := fs.Bool("wip", true, "WIP flag")
	message := fs.String("message", "", "commit-like message")
	if err := fs.Parse(args); err != nil {
		return err
	}
	if *name == "" {
		return errors.New("create: -name is required")
	}
	bodyMD, err := resolveBody(*body, *bodyFile)
	if err != nil {
		return err
	}
	c, err := newClient()
	if err != nil {
		return err
	}
	wipVal := *wip
	post, err := c.CreatePost(context.Background(), esa.PostInput{
		Name:     *name,
		BodyMD:   bodyMD,
		Tags:     splitCSV(*tagsCSV),
		Category: *category,
		WIP:      &wipVal,
		Message:  *message,
	})
	if err != nil {
		return err
	}
	return printJSON(stdout, post)
}

func runUpdate(args []string, stdout io.Writer) error {
	fs := flag.NewFlagSet("update", flag.ContinueOnError)
	number := fs.Int("number", 0, "post number (required)")
	name := fs.String("name", "", "new title")
	bodyFile := fs.String("body-file", "", "path to file containing body_md ('-' for stdin)")
	body := fs.String("body", "", "body_md (use -body-file for longer content)")
	tagsCSV := fs.String("tags", "", "comma-separated tags")
	category := fs.String("category", "", "category")
	wipFlag := fs.String("wip", "", "WIP flag (true/false); empty leaves unchanged")
	message := fs.String("message", "", "commit-like message")
	if err := fs.Parse(args); err != nil {
		return err
	}
	if *number <= 0 {
		return errors.New("update: -number is required")
	}
	bodyMD, err := resolveBody(*body, *bodyFile)
	if err != nil {
		return err
	}
	input := esa.PostInput{
		Name:     *name,
		BodyMD:   bodyMD,
		Tags:     splitCSV(*tagsCSV),
		Category: *category,
		Message:  *message,
	}
	if *wipFlag != "" {
		v, err := strconv.ParseBool(*wipFlag)
		if err != nil {
			return fmt.Errorf("update: -wip: %w", err)
		}
		input.WIP = &v
	}
	c, err := newClient()
	if err != nil {
		return err
	}
	post, err := c.UpdatePost(context.Background(), *number, input)
	if err != nil {
		return err
	}
	return printJSON(stdout, post)
}

func resolveBody(inline, file string) (string, error) {
	if inline != "" && file != "" {
		return "", errors.New("specify only one of -body or -body-file")
	}
	if file == "" {
		return inline, nil
	}
	if file == "-" {
		b, err := io.ReadAll(os.Stdin)
		if err != nil {
			return "", fmt.Errorf("read stdin: %w", err)
		}
		return string(b), nil
	}
	b, err := os.ReadFile(file)
	if err != nil {
		return "", fmt.Errorf("read body file: %w", err)
	}
	return string(b), nil
}

func splitCSV(s string) []string {
	if s == "" {
		return nil
	}
	parts := strings.Split(s, ",")
	out := make([]string, 0, len(parts))
	for _, p := range parts {
		p = strings.TrimSpace(p)
		if p != "" {
			out = append(out, p)
		}
	}
	return out
}

func printJSON(w io.Writer, v any) error {
	enc := json.NewEncoder(w)
	enc.SetIndent("", "  ")
	return enc.Encode(v)
}