import json
import os
import pickle
from collections import defaultdict, OrderedDict

import numpy as np
import pandas as pd
from tqdm import tqdm

# ----------------------------- CONFIG -------------------------------- #
INPUT_JSON = "./src/fuse_esdac/outputs/03_photo_gadm/samples_with_photo_gadm.pkl"
OUTPUT_CSV = "./src/fuse_esdac/outputs/04_table/final_table.csv"
OUTPUT_DICT_PKL = "./src/fuse_esdac/outputs/04_table/final_dict.pkl"
OUTPUT_DICT_JSON = "./src/fuse_esdac/outputs/04_table/final_dict.json"
OUTPUT_META = "./src/fuse_esdac/outputs/04_table/column_meta.json"
OUTPUT_META_NAMES = "./src/fuse_esdac/outputs/04_table/column_names.json"
# --------------------------------------------------------------------- #

# Null normalization rules
NULL_STRINGS = {
    "nan", "null", "none", "", "na", "n/a", "missing", "unknown", "unknown1"
}


def is_null_value(v):
    # Real null
    if v is None:
        return True
    # String forms
    if isinstance(v, str):
        s = v.strip().lower()
        if s in NULL_STRINGS:
            return True
    return False


FILL_VALUES_TO_NULL = {-9000, -90000}
NEGATIVE_FEATURE_KEYWORDS = ("density", "percentage", "content", "stock")
NONE_POSITIVE_FEATURE_KEYWORDS = ("ph_",)


def numeric_or_none(v):
    try:
        return float(v)
    except (TypeError, ValueError):
        return None


def clean_numeric_scalar_value(header, v):
    if is_null_value(v):
        return None

    x = numeric_or_none(v)
    if x is None:
        return v

    if x in FILL_VALUES_TO_NULL:
        return None

    h = header.lower()
    if any(k in h for k in NEGATIVE_FEATURE_KEYWORDS) and x < -0.00001:
        return None
    if any(k in h for k in NONE_POSITIVE_FEATURE_KEYWORDS) and x < 0.00001:
        return None

    return v


def clean_numeric_vector_value(header, v):
    if is_null_value(v):
        return None

    if not isinstance(v, list):
        return v

    cleaned = [
        clean_numeric_scalar_value(header, x)
        for x in v
    ]

    if all(x is None for x in cleaned):
        return None

    return cleaned


def main():
    with open(INPUT_JSON, "rb") as f:
        data = pickle.load(f)

    # 1) Discover variables and enforce unit consistency on (theme:var)
    var_to_unit = {}  # "theme:var" -> unit_str ('' if missing)
    for sid, sample in data.items():
        # force presence of required non-variable fields (surface schema issues early)
        _ = sample["LAT_LONG"]
        _ = sample["GADM_IDS"]
        _ = sample["GADM_NAMES"]
        _ = sample["COUNTRY_CODE"]

        for theme, theme_obj in sample.items():
            if theme in ("LAT_LONG", "GADM_IDS", "GADM_NAMES", "COUNTRY_CODE",
                         "SAMPLE_DATE", "SAMPLE_DEPTH_RANGE_CM", "SAMPLE_SOURCE_DATASET"):
                continue

            # theme_obj is expected to be a dict of variables
            for var, var_obj in theme_obj.items():
                # required fields per your spec (value, source_dataset, distance_to_grid; unit optional)
                _ = var_obj["value"]
                _ = var_obj["source_dataset"]
                _ = var_obj["distance_to_grid (m)"]
                unit = var_obj.get("unit", "")  # empty string if missing

                key = f"{theme}:{var}"
                if key not in var_to_unit:
                    var_to_unit[key] = unit
                else:
                    if var_to_unit[key] != unit:
                        print(f"WARNING: inconsistent unit for '{key}': "
                              f"using '{var_to_unit[key]}' but encountered '{unit}'")

    # 2) Build a stable mapping to final column headers with unit parentheses (including empty ())
    def header_for(key):
        unit = var_to_unit[key]
        return f"{key} ({unit})" if unit else key

    base_cols = ["id", "LAT_LONG", "GADM_IDS", "GADM_NAMES", "COUNTRY_CODE",
                 "SAMPLE_DATE", "SAMPLE_DEPTH_RANGE_CM", "SAMPLE_SOURCE_DATASET"]
    var_cols = [header_for(key) for key in var_to_unit.keys()]
    all_cols = base_cols + var_cols

    # 3) Populate rows and collect meta
    meta_sources = defaultdict(set)  # header -> set of datasets
    meta_distances = defaultdict(list)  # header -> list of numeric distances (non-null only)

    table = []
    for sid, sample in tqdm(data.items(), desc="Building table"):
        row = OrderedDict.fromkeys(all_cols, None)

        row["id"] = sid
        row["LAT_LONG"] = sample["LAT_LONG"]
        row["GADM_IDS"] = sample["GADM_IDS"]
        row["GADM_NAMES"] = sample["GADM_NAMES"]
        row["COUNTRY_CODE"] = sample["COUNTRY_CODE"]
        row["SAMPLE_DATE"] = sample.get("SAMPLE_DATE")
        row["SAMPLE_DEPTH_RANGE_CM"] = sample.get("SAMPLE_DEPTH_RANGE_CM")
        row["SAMPLE_SOURCE_DATASET"] = sample.get("SAMPLE_SOURCE_DATASET")

        for theme, theme_obj in sample.items():
            if theme in ("LAT_LONG", "GADM_IDS", "GADM_NAMES", "COUNTRY_CODE",
                         "SAMPLE_DATE", "SAMPLE_DEPTH_RANGE_CM", "SAMPLE_SOURCE_DATASET"):
                continue

            for var, var_obj in theme_obj.items():
                key = f"{theme}:{var}"
                header = header_for(key)

                v = var_obj["value"]
                if is_null_value(v):
                    v = None
                row[header] = v  # write to final header (with unit parentheses)

                # --- meta: collect sources regardless of v ---
                src = var_obj["source_dataset"]
                if isinstance(src, str) and src.strip():
                    meta_sources[header].add(src)

                # --- meta: collect non-null distances only ---
                dist = var_obj["distance_to_grid (m)"]
                if not is_null_value(dist):
                    try:
                        meta_distances[header].append(float(dist))
                    except (TypeError, ValueError):
                        # Surface bad distance type immediately
                        raise TypeError(f"distance_to_grid (m) not numeric for '{header}' in sample '{sid}': {dist!r}")

        table.append(row)

    df = pd.DataFrame(table, columns=all_cols)

    # 4) Warn for columns that are entirely null
    for col in var_cols:
        if df[col].isna().all():
            print(f"WARNING: column has all null values -> {col}")

    # 5) Build column_meta.json before cleaning
    def py_type(x):
        if isinstance(x, bool):
            return "bool"
        if isinstance(x, int):
            return "int"
        if isinstance(x, float):
            return "float"
        if isinstance(x, str):
            return "string"
        return None  # ignore other types

    meta = {}
    total_rows = len(df)

    for header in var_cols:
        # ----- distance stats -----
        dists = np.array(meta_distances[header], dtype=float) if meta_distances[header] else np.array([])
        if dists.size > 0:
            stats = {
                "min": float(np.min(dists)),
                "max": float(np.max(dists)),
                "mean": float(np.mean(dists)),
                "std": float(np.std(dists)),
                "median": float(np.median(dists)),
            }
        else:
            stats = {
                "min": None,
                "max": None,
                "mean": None,
                "std": None,
                "median": None,
            }

        # ----- detect array-valued or scalar -----
        col_vals = df[header].tolist()
        first_non_null = next((v for v in col_vals if v is not None), None)

        if isinstance(first_non_null, list):
            is_array = True
            flat_vals = []
            for v in col_vals:
                if isinstance(v, list):
                    flat_vals.extend(v)
            type_counts = {}
            for v in flat_vals:
                t = py_type(v)
                if t:
                    type_counts[t] = type_counts.get(t, 0) + 1
        else:
            is_array = False
            type_counts = {}
            for v in col_vals:
                t = py_type(v)
                if t:
                    type_counts[t] = type_counts.get(t, 0) + 1

        datatype = max(type_counts.items(), key=lambda x: x[1])[0] if type_counts else "unknown"
        null_fraction = float(df[header].isna().sum()) / total_rows

        meta[header] = {
            "source_datasets": sorted(meta_sources[header]),
            "distance_to_grid_stats (m)": stats,
            "null_fraction": null_fraction,
            "datatype": datatype,
            "is_array_valued": is_array,
            "description": "",
        }

    # 6) Clean numeric scalar columns only
    cleaned_cells = {}
    cleaned_columns = defaultdict(int)

    for header in var_cols:
        if meta[header]["datatype"] not in ("int", "float"):
            continue
        if not meta[header]["is_array_valued"]:
            for row_i, v in df[header].items():
                new_v = clean_numeric_scalar_value(header, v)
                if not (
                        pd.isna(new_v) and pd.isna(v)
                ) and new_v != v:
                    df.at[row_i, header] = new_v
                    cleaned_cells[(row_i, header)] = new_v
                    cleaned_columns[header] += 1
        else:
            for row_i, v in df[header].items():
                new_v = clean_numeric_vector_value(header, v)
                if new_v != v:
                    df.at[row_i, header] = new_v
                    cleaned_cells[(row_i, header)] = new_v
                    cleaned_columns[header] += 1

    if cleaned_columns:
        print("Cleaned columns:")
        for header, n in sorted(cleaned_columns.items()):
            print(f"  {header}: {n} cells")
    else:
        print("Cleaned columns: none")

    # 7) Write cleaned values back to dict
    for row_i, row in df.iterrows():
        sid = row["id"]
        sample = data[sid]

        for theme, theme_obj in sample.items():
            if theme in ("LAT_LONG", "GADM_IDS", "GADM_NAMES", "COUNTRY_CODE",
                         "SAMPLE_DATE", "SAMPLE_DEPTH_RANGE_CM", "SAMPLE_SOURCE_DATASET"):
                continue

            for var, var_obj in theme_obj.items():
                key = f"{theme}:{var}"
                header = header_for(key)

                if (row_i, header) in cleaned_cells:
                    var_obj["value"] = cleaned_cells[(row_i, header)]

    # 8) Save outputs
    os.makedirs(os.path.dirname(OUTPUT_CSV), exist_ok=True)

    df_out = df.copy()
    df_out = df_out.replace({np.nan: None})
    df_out.to_csv(OUTPUT_CSV, index=False, encoding="utf-8", na_rep="")

    # Write cleaned dict as pickle
    with open(OUTPUT_DICT_PKL, "wb") as f:
        pickle.dump(data, f)

    # Write cleaned dict as json
    with open(OUTPUT_DICT_JSON, "w", encoding="utf-8") as f:
        json.dump(
            data,
            f,
            indent=2,
            ensure_ascii=False
        )

    with open(OUTPUT_META, "w", encoding="utf-8") as f:
        json.dump(meta, f, indent=2)

    with open(OUTPUT_META_NAMES, "w", encoding="utf-8") as f:
        json.dump(
            {"column_names": sorted(meta.keys())},
            f,
            indent=2,
            ensure_ascii=False,
        )

    print("Done.")
    print(f"Rows: {len(df)}  Columns: {len(df.columns)}")
    print(f"Cleaned cells: {len(cleaned_cells)}")
    print(
        f"Saved: {OUTPUT_CSV}, "
        f"{OUTPUT_DICT_PKL}, {OUTPUT_DICT_JSON}, "
        f"{OUTPUT_META}, {OUTPUT_META_NAMES}"
    )


if __name__ == "__main__":
    main()