package cli

import (
	"flag"
	"fmt"
	"io"
)

type cmdHelp struct {
	name     string
	synopsis string
	summary  string
}

// agentCmds emit machine-readable JSON; adminCmds are human-readable.
var agentCmds = []cmdHelp{
	{"list", "list --account <name> [--folder F] [--new] [--limit N] [--before U] [--since U]", "List message headers, newest first."},
	{"get", "get --account <name> [--folder F] --uid <uid>", "Fetch one full message (body + attachments)."},
	{"search", "search --account <name> [--folder F] [--from A] [--subject-contains S] [--text S] [--since-date D] [--before-date D] [--limit N]", "Server-side IMAP search."},
	{"ack", "ack --account <name> [--folder F] --uid-list U1,U2,…", "Mark message(s) processed."},
	{"send", "send --account <name> --to A… [--cc A…] [--bcc A…] --subject S --body B [--attach P]… [--reply-to U [--folder F]]", "Send or reply (RW accounts only)."},
}

var adminCmds = []cmdHelp{
	{"init", "init", "Create the database and add the first account (interactive)."},
	{"account", "account <add|edit|remove|list> [flags]", "Manage accounts (add/edit accept flags, or run with none for an interactive form)."},
	{"whitelist", "whitelist <in|out> <add|remove|list> --account <name> [--address A]", "Manage inbound/outbound whitelists."},
	{"config", "config <set|get> <key> [value]", "Get or set global settings (e.g. audit_retention_days)."},
	{"audit", "audit list [--account <name>] [--limit N]", "Show recent audit-log entries."},
	{"doctor", "doctor [--account <name>]", "Check each account's IMAP/SMTP connectivity and auth."},
	{"version", "version", "Print the emcli version."},
	{"help", "help [command]", "Show this help, or detailed usage for one command."},
}

func helpIndex() map[string]cmdHelp {
	m := make(map[string]cmdHelp, len(agentCmds)+len(adminCmds))
	for _, c := range append(append([]cmdHelp{}, agentCmds...), adminCmds...) {
		m[c.name] = c
	}
	return m
}

// helpRequested reports whether an argument is a help flag/word.
func helpRequested(s string) bool {
	return s == "help" || s == "-h" || s == "--help"
}

// printMainHelp writes the top-level command catalogue.
func printMainHelp(w io.Writer) {
	fmt.Fprint(w, "emcli — guard-railed email gateway for agents\n\n")
	fmt.Fprint(w, "Usage:\n  emcli <command> [flags]\n\n")
	fmt.Fprint(w, "Agent commands (machine-readable JSON on stdout):\n")
	for _, c := range agentCmds {
		fmt.Fprintf(w, "  %-10s %s\n", c.name, c.summary)
	}
	fmt.Fprint(w, "\nAdmin commands (human-readable):\n")
	for _, c := range adminCmds {
		fmt.Fprintf(w, "  %-10s %s\n", c.name, c.summary)
	}
	fmt.Fprint(w, "\nRun \"emcli <command> --help\" for a command's flags.\n")
	fmt.Fprint(w, "\nEnvironment:\n")
	fmt.Fprint(w, "  EMCLI_KEY   base64-encoded 32-byte AES key; required for any command that uses the database\n")
	fmt.Fprint(w, "  EMCLI_DB    database path (default ~/.config/emcli/emcli.db; %AppData%\\emcli\\emcli.db on Windows)\n")
}

// printCmdUsage writes "Usage: emcli <synopsis>" and the summary for one command.
func printCmdUsage(w io.Writer, name string) {
	if h, ok := helpIndex()[name]; ok {
		fmt.Fprintf(w, "Usage: emcli %s\n\n%s\n", h.synopsis, h.summary)
		return
	}
	fmt.Fprintf(w, "Usage: emcli %s\n", name)
}

// usageFlags makes a flag set print the command's synopsis/summary followed by
// its flags whenever flag prints usage (on -h/--help or a flag error).
func usageFlags(fs *flag.FlagSet, name string, w io.Writer) {
	fs.Usage = func() {
		printCmdUsage(w, name)
		fmt.Fprintln(w, "\nFlags:")
		fs.PrintDefaults()
	}
}