#pragma once

#include "fgc/ImuMount.h"
#include "fgc/Geometry.h"

#include <map>
#include <string>
#include <utility>
#include <vector>

namespace fgc {

// Typed application configuration. Replaces the ad-hoc std::map<string,string>
// lookups that were scattered through main.cpp.

struct GeneralConfig {
    std::string tower_name = "Unnamed";
    int         image_interval = 5;   // seconds between captures
    bool        debug = false;        // print motor telemetry each loop tick
};

// [Board]: which computer this is. Assembly data - it changes only when the
// machine is physically replaced, so it belongs in hardware.ini, not config.ini.
struct BoardConfig {
    std::string model;         // e.g. "lattepanda-3-delta", "lattepanda-iota"
    std::string firmware_env;  // PlatformIO env for the motor MCU ("leonardo", ...)
};

// [Hardware]: what is actually fitted to THIS rig.
//
// The point of declaring it is that the rest of the program degrades gracefully
// when something is missing - TestRunner skips the pitch and IMU leaves, CamEvent
// falls back to encoder pitch, CaptureScheduler sends the single-axis MOVE form -
// which is right for a rig that genuinely lacks them, and indistinguishable from a
// FAILURE on a rig that does not. Declaring what was assembled is what lets
// startup tell those two apart.
struct HardwareConfig {
    // Empty means "not declared": nothing was stated, so nothing is reconciled.
    // This is the state every existing tower is in until it gets a hardware.ini.
    std::vector<std::string> axes;     // e.g. {"yaw", "pitch"}
    std::string              imu;      // sensor model, or "none"
    std::string              env;      // sensor model, or "none"
    std::vector<std::string> cameras;  // the [Camera.<name>] blocks expected to exist

    // Was a hardware.ini actually read? False on every tower that has not been
    // migrated yet, and the switch that keeps this change invisible on rollout.
    bool declared = false;
    // Where it came from, for logging and for `test hardware` to cite.
    std::string source_path;

    // True when `name` is listed in axes. An UNDECLARED rig answers true for
    // everything: with nothing stated there is nothing to contradict, and callers
    // must keep behaving exactly as they did before.
    bool hasAxis(const std::string& name) const;
    // "yaw, pitch" - for log lines and test output.
    std::string axesLabel() const;
};

// [Motor.<axis>] - what this tower's drivetrain IS, one block per axis. These
// change only when the motor, gearbox or driver board changes, so they belong in
// hardware.ini beside the rest of the assembly description.
//
// Currents are milliamps RMS per phase, NOT register values: the conversion needs
// the sense resistor fitted to this particular driver board, so the host owns it
// and sends the firmware the registers it computed (see TmcCurrent.h).
struct AxisDrivetrainConfig {
    bool   declared          = false;  // any [Motor.<axis>] key present at all
    double r_sense_ohm       = 0.0;    // sense resistor on this axis's TMC board
    double run_current_ma    = 0.0;    // 0 = undeclared -> nothing is sent
    double homing_current_ma = 0.0;    // defaults to run_current_ma

    // Mechanical angle between the hard endstops. A nameplate fact, not a
    // calibration: homing measures the travel in counts, and dividing by this
    // yields [Motor] <axis>_counts_per_deg, which lives in config.ini and is
    // saved with history. Keeping them in different files AND different keys is
    // deliberate - hardware.ini is merged over config.ini and wins, so a shared
    // key would silently discard every saved calibration.
    double travel_deg        = 0.0;    // 0 = undeclared -> nothing is derived

    // Production move speed, as a PHYSICAL quantity. VMAX is a register value
    // whose meaning depends on the gear ratio - 30000 is 21.8 deg/s on the Delta
    // fleet and 6.0 deg/s on the IOTA - so declaring it in register units makes
    // the number unportable and, in practice, wrong when copied between towers.
    // The host converts through counts_per_deg and sends SPEED; see AxisSpeed.h.
    double scan_speed_deg_s  = 8.0;    // kDefaultScanSpeedDegPerSec

    // True when the homing current is genuinely lower than the run current, i.e.
    // when the reduction is load-bearing and homing without it risks the rig.
    bool reducesForHoming() const {
        return run_current_ma > 0.0 && homing_current_ma > 0.0 &&
               homing_current_ma < run_current_ma;
    }
};

struct DrivetrainConfig {
    AxisDrivetrainConfig yaw;
    AxisDrivetrainConfig pitch;
};

struct NetworkConfig {
    std::string broker_ip = "127.0.0.1";  // MQTT broker host/IP, or a full tcp://... URI
    int         mqtt_port = 1883;          // ignored when broker_ip carries its own port
    std::string mqtt_user;                 // see secrets note below
    std::string mqtt_pw;

    // Paho serverURI for broker_ip + mqtt_port, e.g. "tcp://10.0.0.5:1883".
    //
    // Built here rather than handing Paho a bare address and relying on its
    // default port, so the port is explicit, configurable and visible in the log.
    // Two precedence rules, both to keep existing configs working:
    //   - broker_ip containing "://" is a URI the operator owns: returned verbatim,
    //     mqtt_port ignored (it may already have a port, or a ws:// path to break).
    //   - broker_ip already carrying "host:port" keeps that port; mqtt_port ignored.
    // A bare IPv6 address is bracketed, or Paho's rightmost-colon parse would read
    // the last hextet as the port.
    std::string brokerUri() const;
};

struct SerialConfig {
    std::string  device = "/dev/ttyACM0";
    unsigned int baud   = 115200;
};

// Per-profile program behaviour, from [Camera.<name>.<profile>]. These are not
// camera settings - the camera's own settings live entirely in the profile XML -
// but timing the program must observe around them.
struct CameraProfileTiming {
    int settle_wait_ms   = 1000;   // hold after standstill before keeping a frame
    int frame_timeout_ms = 2000;   // give up on the waypoint after this
};

// One camera, from a [Camera.<name>] block. Nothing is implied by position: the
// block names the camera, `label` names its output, `driver` picks the backend.
struct CameraSpec {
    std::string name;                    // the block suffix, e.g. "rgb"
    bool        enabled = true;
    std::string driver  = "vimba";       // only "vimba" is implemented
    std::string id;                      // USB DEV_ id or GigE IP
    std::string label;                   // output subdir + CamEvent "cam"; defaults to name
    std::string profile_dir;             // relative => resolved next to config.ini
    std::string profile = "standard";    // which profile to start in
    int         rotation_deg = 0;        // clockwise; 0/90/180/270

    // Encoding, defaulted from [Camera] and overridable per camera.
    double jxl_distance = 0.8;
    int    jxl_effort   = 4;

    std::map<std::string, CameraProfileTiming> timing;   // by profile name

    // Timing for `profile`, or the defaults when the block does not name it.
    CameraProfileTiming timingFor(const std::string& profile_name) const;
};

struct CameraConfig {
    std::vector<CameraSpec> cameras;     // in config order; empty is a config error
    // [Camera] defaults, inherited by each block unless it overrides them.
    double jxl_distance = 0.8;
    int    jxl_effort   = 4;

    // Enabled cameras only.
    std::vector<const CameraSpec*> active() const;
    // The gimbal must stand still long enough for EVERY active camera, so the
    // scheduler takes the longest wait rather than the first camera's.
    int maxSettleWaitMs() const;
    int maxFrameTimeoutMs() const;
};

struct PathsConfig {
    // Where captured .jxl images are written. Supports leading ~ and $ENV
    // expansion. Empty => resolved to a sensible default at load time.
    std::string output_dir;
};

struct FeaturesConfig {
    bool enable_mqtt   = true;
    bool enable_camera = true;
    bool enable_serial = true;
    bool enable_imu    = false;  // Xsens MTi orientation/IMU (off by default)
    bool mock_camera   = false;  // use a simulated camera instead of Vimba X
    bool mock_serial   = false;  // use a simulated motor controller
    bool mock_imu      = false;  // use a simulated IMU instead of the MTi
    bool enable_env    = false;  // ambient temp/humidity sensor (off by default)
    bool mock_env      = false;  // use a simulated env sensor instead of the SHT41

    // Refuse to start when hardware.ini declares a subsystem this rig does not
    // have (HardwarePresence.h). Off by default so that gaining a hardware.ini
    // cannot change how a tower behaves: it is turned on per tower once that
    // file is known good, and the fleet-wide flip is a config change rather than
    // a release. --degraded overrides it for field triage.
    bool strict_presence = false;
};

// Where a sensor's on/off state came from. [Hardware] imu / env DECLARE what is
// fitted; [Features] enable_imu / enable_env are the older flags that said the
// same thing a second time, and could disagree with it.
enum class SensorEnableSource {
    Declaration,  // [Hardware] imu / env said so - the new, single source
    Flag,         // no declaration, but the legacy flag was written explicitly
    Default,      // neither: the built-in default
};

struct SensorEnable {
    bool               enabled  = false;
    SensorEnableSource source   = SensorEnableSource::Default;
    // The legacy flag was present AND contradicted the declaration. The
    // declaration wins; this exists so the stale key can be named and deleted
    // rather than silently ignored.
    bool               conflict = false;
};

// Resolve one sensor's enablement.
//
// The declaration wins wherever it exists, which is what retires the flag: a rig
// that says `imu = mti-630` needs no second key agreeing with it, and a rig that
// says `imu = none` cannot be contradicted into enabling one. With nothing
// declared - every tower until it is migrated - the flag governs exactly as
// before.
SensorEnable resolveSensorEnable(const std::string& declared, bool flag_value, bool flag_present);

// [IMU]: Xsens MTi connected over the LattePanda's RS-232 UART (a hardware
// /dev/ttyS* node, stable across reboots — not a USB device).
struct ImuConfig {
    std::string  device = "";       // e.g. /dev/ttyS4; empty => required when enabled
    unsigned int baud   = 115200;

    // How the unit is bolted to the gimbal, as [IMU] x/y/z. Every reading the
    // program produces is rotated into the gimbal's NED body frame by this, so
    // nothing downstream ever sees the sensor frame. See ImuMount.h for the
    // convention; the default is the identity, which changes nothing.
    ImuMount mount;
};

// [Env]: ambient temperature/humidity sensor (SHT41) on the LattePanda's own
// native I2C bus — NOT the Arduino/motor serial link. Bus number varies by
// board; confirm with `i2cdetect -y N` (expect the SHT41 at 0x44).
struct EnvConfig {
    std::string  i2c_device = "/dev/i2c-1";  // empty => required when enabled
    unsigned int i2c_addr   = 0x44;
    int          period_ms  = 2000;          // sample interval
};

struct LoggingConfig {
    std::string level;  // trace|debug|info|warn|error|off; empty => default (CLI overrides)
    std::string trace;  // verbatim wire-trace categories: serial,mqtt,camera,control,all,none
};

struct UiConfig {
    bool enable_tui = false;  // false => headless line console (default); CLI --tui/--no-tui override
};

// [Scan]: source of the capture scan grid (the (yaw,pitch) waypoints the
// auto-sweep steps through). If grid_file is set, the CSV is loaded verbatim;
// otherwise a grid is generated from the parameters below (see ScanGrid).
struct ScanConfig {
    std::string grid_file;                  // path to an editable yaw_deg,pitch_deg CSV; empty => generate
    int         yaw_intervals = 56;         // generated: yaw positions across [yaw_min_deg, yaw_max_deg]
    double      yaw_min_deg   = -90.0;
    double      yaw_max_deg   = 90.0;
    std::string pitch_levels  = "0";        // generated: comma list of pitch elevations (deg)
};

// [Test] / [TestProfile.<name>]: the hardware self-test command. A profile is a
// named bundle of repetition counts, sampling windows and pass thresholds; the
// modules read the values they care about by key (open map so new tests can add
// knobs without touching the loader).
struct TestProfile {
    std::string                        name;
    std::map<std::string, double>      params;  // numeric knobs: reps, *_window_ms, *_max_*
    std::map<std::string, std::string> text;    // raw values incl. comma lists (e.g. step sizes)

    double                   get(const std::string& key, double fallback) const;
    int                      geti(const std::string& key, int fallback) const;
    bool                     getBool(const std::string& key, bool fallback) const;
    std::string              gets(const std::string& key, const std::string& fallback = "") const;
    std::vector<long>        getLongList(const std::string& key) const;  // parse "200,500,1000"
};

struct TestConfig {
    std::string                        default_profile = "standard";
    std::string                        baseline_file;   // empty => <logdir>/test_baseline.txt
    std::map<std::string, TestProfile> profiles;

    // `test hardware camera` USB preconditions. Both are machine facts rather
    // than tuning: the threshold is what frame delivery needs (known-issues #19),
    // and the LPM node's path differs per board, so it cannot be guessed. Left
    // empty, the LPM check reports "not checked" rather than passing.
    int         usbfs_min_mb = 1000;
    std::string usb3_lpm_path;

    const TestProfile* find(const std::string& name) const;  // nullptr if absent
};

struct AppConfig {
    GeneralConfig  general;
    NetworkConfig  network;
    SerialConfig   serial;
    CameraConfig   camera;
    PathsConfig    paths;
    BoardConfig    board;     // [Board]    from hardware.ini
    HardwareConfig hardware;  // [Hardware] from hardware.ini
    FeaturesConfig features;
    LoggingConfig  logging;
    UiConfig       ui;        // [UI] terminal dashboard toggle
    Geometry       geometry;  // [Motor] degrees<->counts maps (yaw + pitch)
    DrivetrainConfig drivetrain;  // [Motor.<axis>] from hardware.ini
    // [Motor] how long a full two-end homing may take before the host calls it
    // failed. A property of the drivetrain, not of this program: a high gear
    // ratio searching at a gentle speed takes minutes.
    int            homing_timeout_s = 65;
    // [Motor] clearance kept from each hard endstop, in counts. Sent to the
    // firmware (MARGIN), which enforces it; kept in counts rather than degrees
    // because it must apply at homing time, before any degree map is trusted.
    long           yaw_soft_margin_counts   = 5000;
    long           pitch_soft_margin_counts = 5000;
    long           enc_error_warn_counts = 400;       // [Motor] live encoder-error WARN (0=off)
    ScanConfig     scan;      // [Scan] grid source
    ImuConfig      imu;       // [IMU] Xsens MTi serial device
    EnvConfig      env;       // [Env] SHT41 ambient sensor, LattePanda I2C
    TestConfig     test;      // [Test] hardware self-test profiles

    // Capture rate in images/second (derived from general.image_interval).
    double image_rate() const;
};

// Loads and validates configuration.
//
// Secrets: mqtt_user / mqtt_pw are taken from the environment variables
// FGC_MQTT_USER / FGC_MQTT_PW when present; the INI values are a fallback.
class ConfigLoader {
public:
    // Reads the INI file at `path` (via the bundled inih parser), maps it into
    // a typed AppConfig, applies environment overrides, and validates it.
    // Throws std::runtime_error with a clear message on failure.
    //
    // `hardware_path`, when given, is read AFTER the config and its keys win. It
    // carries the assembly-time description of the machine ([Board], [Hardware],
    // and the device bindings), which outlives any amount of operational tuning.
    // Passing "" keeps the historical behaviour exactly: everything comes from
    // config.ini and `hardware.declared` stays false.
    static AppConfig loadFromFile(const std::string& path,
                                  const std::string& hardware_path = "");

    // Same mapping/validation logic, but from an already-parsed key->value map
    // ("Section.name" => value). Exposed for unit testing without file IO.
    static AppConfig fromMap(const std::map<std::string, std::string>& kv);
};

// Return `contents` with the given `key = value` pairs set under `[section]`:
// existing keys in that section are replaced in place (comments/order preserved),
// and any missing ones are appended in a `[section]` block at the end. Pure (no
// I/O) so it is unit-testable.
//
// With a non-empty `provenance`, a key whose value actually CHANGES also gets its
// previous value kept above it as a comment, so a calibration can be reverted by
// hand:
//
//     ;prev yaw_heading_at_center = 0.0   ; 2026-09-11T14:32Z, gimbal heading setup
//     yaw_heading_at_center = 127.4
//
// Exactly one generation is kept - an existing `;prev` for a changing key is
// replaced, not appended to - and unchanged keys are left completely alone, so
// the file grows once and then holds steady.
std::string updateIniSectionKeys(const std::string& contents, const std::string& section,
                                 const std::vector<std::pair<std::string, std::string>>& kv,
                                 const std::string& provenance = "");

// Persist the live `[Motor]` geometry (counts_per_deg / center_count /
// deg_at_center for both axes, plus the endstop margins) back into the INI file
// at `path`. Written via a temp file and rename, so an interrupted save cannot
// leave a truncated config behind. Returns true on success.
//
// `provenance` names what produced these values (e.g. "2026-09-11T14:32Z, gimbal
// heading setup"); when given, superseded values are kept as `;prev` comments.
bool saveMotorGeometry(const std::string& path, const Geometry& geo, long yaw_margin,
                       long pitch_margin, const std::string& provenance = "");

}  // namespace fgc