package main

import (
	"context"
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"io"
	"net/url"
	"strconv"
	"strings"
)

func runTodos(ctx context.Context, client *Client, args []string, stdin io.Reader, stdout io.Writer) error {
	if len(args) == 0 {
		return runTodosList(ctx, client, nil, stdout)
	}
	if args[0] == "help" || args[0] == "--help" || args[0] == "-h" {
		_, _ = io.WriteString(stdout, "Usage: cmsctl todos [list] [--done=true|false|open|done|all] [--open] [--prio low|medium|high] [--q query] [--limit N] [--offset N]\n       cmsctl todos done <id>\n       cmsctl todos reopen <id>\n       cmsctl todos get <id>\n       cmsctl todos create --note '...' [--prio low|medium|high] [--location '...'] [--url '...']\n       cmsctl todos delete <id> --yes\n")
		return nil
	}

	// If the first argument is a flag (e.g. `cmsctl todos --open`), treat as `list`
	if strings.HasPrefix(args[0], "-") {
		return runTodosList(ctx, client, args, stdout)
	}

	switch args[0] {
	case "list":
		return runTodosList(ctx, client, args[1:], stdout)
	case "done", "mark-done":
		return runTodosSetDone(ctx, client, args[1:], true, stdout)
	case "reopen", "undone", "open":
		return runTodosSetDone(ctx, client, args[1:], false, stdout)
	case "get":
		id, err := requireID(args[1:], "cmsctl todos get requires a todo id")
		if err != nil {
			return err
		}
		body, err := client.get(ctx, client.cmsURL("/nodes/"+escapePathSegment(id)))
		if err != nil {
			return err
		}
		return writeRaw(stdout, body)
	case "create":
		return runTodosCreate(ctx, client, args[1:], stdin, stdout)
	case "delete":
		return cmsDeleteNode(ctx, client, args[1:], stdout)
	default:
		return fmt.Errorf("unknown todos command %q (use --help)", args[0])
	}
}

type doneFlag struct {
	set   bool
	value string
}

func (d *doneFlag) String() string {
	return d.value
}

func (d *doneFlag) Set(s string) error {
	d.set = true
	d.value = strings.TrimSpace(strings.ToLower(s))
	return nil
}

func (d *doneFlag) IsBoolFlag() bool {
	return true
}

func runTodosList(ctx context.Context, client *Client, args []string, stdout io.Writer) error {
	fs := flag.NewFlagSet("todos list", flag.ContinueOnError)
	var done doneFlag
	fs.Var(&done, "done", "filter by completion status: true|false, open|done, or all")
	openOnly := fs.Bool("open", false, "filter to open / uncompleted todos (shorthand for --done=false)")
	prio := fs.String("prio", "", "priority filter: low, medium, or high")
	q := fs.String("q", "", "search substring over note/location/url")
	limit := fs.Int("limit", 100, "page size; use 0 for all")
	offset := fs.Int("offset", 0, "page offset")
	fs.SetOutput(io.Discard)
	if err := fs.Parse(args); err != nil {
		return err
	}

	query := url.Values{
		"limit":  {strconv.Itoa(*limit)},
		"offset": {strconv.Itoa(*offset)},
	}
	if *prio != "" {
		query.Set("prio", strings.ToLower(*prio))
	}
	if *q != "" {
		query.Set("q", *q)
	}

	if *openOnly {
		query.Set("done", "false")
	} else if done.set {
		switch done.value {
		case "true", "t", "1", "done", "yes":
			query.Set("done", "true")
		case "false", "f", "0", "open", "no":
			query.Set("done", "false")
		case "all", "":
			// omit parameter to fetch all
		default:
			return fmt.Errorf("invalid --done value %q: use true, false, open, done, or all", done.value)
		}
	}

	body, err := client.get(ctx, client.cmsURL("/todos")+"?"+query.Encode())
	if err != nil {
		return err
	}
	return writeRaw(stdout, body)
}

func runTodosSetDone(ctx context.Context, client *Client, args []string, done bool, stdout io.Writer) error {
	id, err := requireID(args, "cmsctl todos done requires a todo id")
	if err != nil {
		return err
	}
	patch := map[string]any{
		"data": map[string]any{
			"done": done,
		},
	}
	body, err := json.Marshal(patch)
	if err != nil {
		return err
	}
	response, err := client.patchBody(ctx, client.cmsURL("/nodes/"+escapePathSegment(id)), body, "application/json")
	if err != nil {
		return err
	}
	return writeRaw(stdout, response)
}

func runTodosCreate(ctx context.Context, client *Client, args []string, stdin io.Reader, stdout io.Writer) error {
	fs := flag.NewFlagSet("todos create", flag.ContinueOnError)
	note := fs.String("note", "", "improvement note / description")
	prio := fs.String("prio", "medium", "priority: low, medium, or high")
	done := fs.Bool("done", false, "initial completion status")
	location := fs.String("location", "", "admin view title where suggestion was filed")
	rawURL := fs.String("url", "", "page URL where suggestion was filed")
	tags := fs.String("tags", "", "comma-separated tags")
	input := fs.String("input", "", "complete request JSON file or - for stdin")
	fs.SetOutput(io.Discard)
	if err := fs.Parse(args); err != nil {
		return err
	}

	body, err := readInput(stdin, *input, fs.Args())
	if err != nil {
		return fmt.Errorf("read todo input: %w", err)
	}
	if len(body) == 0 {
		if strings.TrimSpace(*note) == "" {
			return errors.New("todos create requires --note")
		}
		data := map[string]any{
			"note": strings.TrimSpace(*note),
			"prio": *prio,
			"done": *done,
		}
		if *location != "" {
			data["location"] = *location
		}
		if *rawURL != "" {
			data["url"] = *rawURL
		}
		node := map[string]any{
			"dataType": "todo",
			"data":     data,
			"tags":     splitCSV(*tags),
		}
		body, err = json.Marshal(node)
		if err != nil {
			return err
		}
	}
	if !json.Valid(body) {
		return errors.New("create todo input is not valid JSON")
	}
	response, err := client.postBody(ctx, client.cmsURL("/nodes"), body, "application/json")
	if err != nil {
		return err
	}
	return writeRaw(stdout, response)
}